Merge release 1.73.x to main (#336)

* remove cronet files

* remove cronet files

* Sync c-core 1.72.0-pre1

* use c++17 for swift package

* update ios deployment target to 15.0

* Sync c-core 1.72.0

* Sync c-core 1.73.0-pre1

* include additional files

* Re-sync c-core 1.73.0-pre1

* exclude inc files from swift package

* upgrade abseil swift to 0.20250127.1 (#330)

* Sync c-core 1.73.0-pre2

* Sync c-core 1.73.0

* Sync c-core 1.73.1

.github/workflows/manual-push-a-pod.yml

@@ -23,7 +23,7 @@ env:
 
 jobs:
   release-cocoapod:
-    runs-on: macos-12
+    runs-on: macos-14
     steps:
       - name: Repo checkout
         uses: actions/checkout@v3

Package.swift

@@ -24,7 +24,7 @@ let package = Package(
   ],
 
   dependencies: [
-    .package(url: "https://github.com/firebase/abseil-cpp-SwiftPM.git", "0.20240722.0"..<"0.20240723.0"),
+    .package(url: "https://github.com/firebase/abseil-cpp-SwiftPM.git", "0.20250127.0"..<"0.20250128.0"),
     .package(url: "https://github.com/firebase/boringssl-SwiftPM.git", "0.32.0"..<"0.33.0"),
   ],
 
@@ -41,6 +41,8 @@ let package = Package(
         "src/cpp/",
         "third_party/upb/upb/port/def.inc",
         "third_party/upb/upb/port/undef.inc",
+        "third_party/utf8_range/utf8_range_sse.inc",
+        "third_party/utf8_range/utf8_range_neon.inc",
         "third_party/re2/LICENSE",
         "third_party/utf8_range/LICENSE",
         "third_party/xxhash/LICENSE",
@@ -82,6 +84,8 @@ let package = Package(
       path: basePath,
       exclude: [
         "tests",
+        "include/grpcpp/ports_undef.inc",
+        "include/grpcpp/ports_def.inc",
       ],
       sources: [
         "src/cpp/",

gRPC-C++.podspec

@@ -22,7 +22,7 @@
 Pod::Spec.new do |s|
   s.name     = 'gRPC-C++'
   # TODO (mxyan): use version that match gRPC version when pod is stabilized
-  version = '1.72.1'
+  version = '1.73.1'
   s.version  = version
   s.summary  = 'gRPC C++ library'
   s.homepage = 'https://grpc.io'
@@ -232,7 +232,7 @@ Pod::Spec.new do |s|
     ss.dependency "#{s.name}/Privacy", version
     ss.dependency "#{s.name}/Interface", version
     ss.dependency 'gRPC-Core', version
-    abseil_version = '~> 1.20240722.0'
+    abseil_version = '~> 1.20250127.1'
     ss.dependency 'abseil/algorithm/container', abseil_version
     ss.dependency 'abseil/base/base', abseil_version
     ss.dependency 'abseil/base/config', abseil_version
@@ -240,6 +240,7 @@ Pod::Spec.new do |s|
     ss.dependency 'abseil/base/log_severity', abseil_version
     ss.dependency 'abseil/base/no_destructor', abseil_version
     ss.dependency 'abseil/cleanup/cleanup', abseil_version
+    ss.dependency 'abseil/container/btree', abseil_version
     ss.dependency 'abseil/container/flat_hash_map', abseil_version
     ss.dependency 'abseil/container/flat_hash_set', abseil_version
     ss.dependency 'abseil/container/inlined_vector', abseil_version
@@ -294,6 +295,7 @@ Pod::Spec.new do |s|
                       'src/core/channelz/channel_trace.h',
                       'src/core/channelz/channelz.h',
                       'src/core/channelz/channelz_registry.h',
+                      'src/core/channelz/ztrace_collector.h',
                       'src/core/client_channel/backup_poller.h',
                       'src/core/client_channel/client_channel.h',
                       'src/core/client_channel/client_channel_args.h',
@@ -393,7 +395,6 @@ Pod::Spec.new do |s|
                       'src/core/ext/transport/chttp2/transport/bin_encoder.h',
                       'src/core/ext/transport/chttp2/transport/call_tracer_wrapper.h',
                       'src/core/ext/transport/chttp2/transport/chttp2_transport.h',
-                      'src/core/ext/transport/chttp2/transport/context_list_entry.h',
                       'src/core/ext/transport/chttp2/transport/decode_huff.h',
                       'src/core/ext/transport/chttp2/transport/flow_control.h',
                       'src/core/ext/transport/chttp2/transport/frame.h',
@@ -412,8 +413,10 @@ Pod::Spec.new do |s|
                       'src/core/ext/transport/chttp2/transport/hpack_parser_table.h',
                       'src/core/ext/transport/chttp2/transport/http2_settings.h',
                       'src/core/ext/transport/chttp2/transport/http2_status.h',
+                      'src/core/ext/transport/chttp2/transport/http2_ztrace_collector.h',
                       'src/core/ext/transport/chttp2/transport/huffsyms.h',
                       'src/core/ext/transport/chttp2/transport/internal.h',
+                      'src/core/ext/transport/chttp2/transport/internal_channel_arg_names.h',
                       'src/core/ext/transport/chttp2/transport/legacy_frame.h',
                       'src/core/ext/transport/chttp2/transport/ping_abuse_policy.h',
                       'src/core/ext/transport/chttp2/transport/ping_callbacks.h',
@@ -951,7 +954,9 @@ Pod::Spec.new do |s|
                       'src/core/lib/event_engine/default_event_engine.h',
                       'src/core/lib/event_engine/default_event_engine_factory.h',
                       'src/core/lib/event_engine/event_engine_context.h',
+                      'src/core/lib/event_engine/extensions/blocking_dns.h',
                       'src/core/lib/event_engine/extensions/can_track_errors.h',
+                      'src/core/lib/event_engine/extensions/channelz.h',
                       'src/core/lib/event_engine/extensions/chaotic_good_extension.h',
                       'src/core/lib/event_engine/extensions/iomgr_compatible.h',
                       'src/core/lib/event_engine/extensions/supports_fd.h',
@@ -1029,7 +1034,6 @@ Pod::Spec.new do |s|
                       'src/core/lib/iomgr/event_engine_shims/endpoint.h',
                       'src/core/lib/iomgr/event_engine_shims/tcp_client.h',
                       'src/core/lib/iomgr/exec_ctx.h',
-                      'src/core/lib/iomgr/executor.h',
                       'src/core/lib/iomgr/internal_errqueue.h',
                       'src/core/lib/iomgr/iocp_windows.h',
                       'src/core/lib/iomgr/iomgr.h',
@@ -1205,12 +1209,16 @@ Pod::Spec.new do |s|
                       'src/core/service_config/service_config_impl.h',
                       'src/core/service_config/service_config_parser.h',
                       'src/core/telemetry/call_tracer.h',
+                      'src/core/telemetry/context_list_entry.h',
+                      'src/core/telemetry/default_tcp_tracer.h',
                       'src/core/telemetry/histogram_view.h',
                       'src/core/telemetry/metrics.h',
                       'src/core/telemetry/stats.h',
                       'src/core/telemetry/stats_data.h',
                       'src/core/telemetry/tcp_tracer.h',
                       'src/core/transport/auth_context.h',
+                      'src/core/transport/endpoint_transport.h',
+                      'src/core/transport/endpoint_transport_client_channel_factory.h',
                       'src/core/tsi/alts/crypt/gsec.h',
                       'src/core/tsi/alts/frame_protector/alts_counter.h',
                       'src/core/tsi/alts/frame_protector/alts_crypter.h',
@@ -1259,6 +1267,7 @@ Pod::Spec.new do |s|
                       'src/core/util/event_log.h',
                       'src/core/util/examine_stack.h',
                       'src/core/util/fork.h',
+                      'src/core/util/function_signature.h',
                       'src/core/util/gcp_metadata_query.h',
                       'src/core/util/gethostname.h',
                       'src/core/util/glob.h',
@@ -1295,6 +1304,7 @@ Pod::Spec.new do |s|
                       'src/core/util/ref_counted_ptr.h',
                       'src/core/util/ref_counted_string.h',
                       'src/core/util/ring_buffer.h',
+                      'src/core/util/shared_bit_gen.h',
                       'src/core/util/single_set_ptr.h',
                       'src/core/util/sorted_pack.h',
                       'src/core/util/spinlock.h',
@@ -1603,6 +1613,7 @@ Pod::Spec.new do |s|
                               'src/core/channelz/channel_trace.h',
                               'src/core/channelz/channelz.h',
                               'src/core/channelz/channelz_registry.h',
+                              'src/core/channelz/ztrace_collector.h',
                               'src/core/client_channel/backup_poller.h',
                               'src/core/client_channel/client_channel.h',
                               'src/core/client_channel/client_channel_args.h',
@@ -1702,7 +1713,6 @@ Pod::Spec.new do |s|
                               'src/core/ext/transport/chttp2/transport/bin_encoder.h',
                               'src/core/ext/transport/chttp2/transport/call_tracer_wrapper.h',
                               'src/core/ext/transport/chttp2/transport/chttp2_transport.h',
-                              'src/core/ext/transport/chttp2/transport/context_list_entry.h',
                               'src/core/ext/transport/chttp2/transport/decode_huff.h',
                               'src/core/ext/transport/chttp2/transport/flow_control.h',
                               'src/core/ext/transport/chttp2/transport/frame.h',
@@ -1721,8 +1731,10 @@ Pod::Spec.new do |s|
                               'src/core/ext/transport/chttp2/transport/hpack_parser_table.h',
                               'src/core/ext/transport/chttp2/transport/http2_settings.h',
                               'src/core/ext/transport/chttp2/transport/http2_status.h',
+                              'src/core/ext/transport/chttp2/transport/http2_ztrace_collector.h',
                               'src/core/ext/transport/chttp2/transport/huffsyms.h',
                               'src/core/ext/transport/chttp2/transport/internal.h',
+                              'src/core/ext/transport/chttp2/transport/internal_channel_arg_names.h',
                               'src/core/ext/transport/chttp2/transport/legacy_frame.h',
                               'src/core/ext/transport/chttp2/transport/ping_abuse_policy.h',
                               'src/core/ext/transport/chttp2/transport/ping_callbacks.h',
@@ -2260,7 +2272,9 @@ Pod::Spec.new do |s|
                               'src/core/lib/event_engine/default_event_engine.h',
                               'src/core/lib/event_engine/default_event_engine_factory.h',
                               'src/core/lib/event_engine/event_engine_context.h',
+                              'src/core/lib/event_engine/extensions/blocking_dns.h',
                               'src/core/lib/event_engine/extensions/can_track_errors.h',
+                              'src/core/lib/event_engine/extensions/channelz.h',
                               'src/core/lib/event_engine/extensions/chaotic_good_extension.h',
                               'src/core/lib/event_engine/extensions/iomgr_compatible.h',
                               'src/core/lib/event_engine/extensions/supports_fd.h',
@@ -2338,7 +2352,6 @@ Pod::Spec.new do |s|
                               'src/core/lib/iomgr/event_engine_shims/endpoint.h',
                               'src/core/lib/iomgr/event_engine_shims/tcp_client.h',
                               'src/core/lib/iomgr/exec_ctx.h',
-                              'src/core/lib/iomgr/executor.h',
                               'src/core/lib/iomgr/internal_errqueue.h',
                               'src/core/lib/iomgr/iocp_windows.h',
                               'src/core/lib/iomgr/iomgr.h',
@@ -2514,12 +2527,16 @@ Pod::Spec.new do |s|
                               'src/core/service_config/service_config_impl.h',
                               'src/core/service_config/service_config_parser.h',
                               'src/core/telemetry/call_tracer.h',
+                              'src/core/telemetry/context_list_entry.h',
+                              'src/core/telemetry/default_tcp_tracer.h',
                               'src/core/telemetry/histogram_view.h',
                               'src/core/telemetry/metrics.h',
                               'src/core/telemetry/stats.h',
                               'src/core/telemetry/stats_data.h',
                               'src/core/telemetry/tcp_tracer.h',
                               'src/core/transport/auth_context.h',
+                              'src/core/transport/endpoint_transport.h',
+                              'src/core/transport/endpoint_transport_client_channel_factory.h',
                               'src/core/tsi/alts/crypt/gsec.h',
                               'src/core/tsi/alts/frame_protector/alts_counter.h',
                               'src/core/tsi/alts/frame_protector/alts_crypter.h',
@@ -2568,6 +2585,7 @@ Pod::Spec.new do |s|
                               'src/core/util/event_log.h',
                               'src/core/util/examine_stack.h',
                               'src/core/util/fork.h',
+                              'src/core/util/function_signature.h',
                               'src/core/util/gcp_metadata_query.h',
                               'src/core/util/gethostname.h',
                               'src/core/util/glob.h',
@@ -2604,6 +2622,7 @@ Pod::Spec.new do |s|
                               'src/core/util/ref_counted_ptr.h',
                               'src/core/util/ref_counted_string.h',
                               'src/core/util/ring_buffer.h',
+                              'src/core/util/shared_bit_gen.h',
                               'src/core/util/single_set_ptr.h',
                               'src/core/util/sorted_pack.h',
                               'src/core/util/spinlock.h',

gRPC-Core.podspec

@@ -21,7 +21,7 @@
 
 Pod::Spec.new do |s|
   s.name     = 'gRPC-Core'
-  version = '1.72.1'
+  version = '1.73.1'
   s.version  = version
   s.summary  = 'Core cross-platform gRPC library, written in C'
   s.homepage = 'https://grpc.io'
@@ -47,7 +47,7 @@ Pod::Spec.new do |s|
   s.requires_arc = false
 
   name = 'grpc'
-  abseil_version = '~> 1.20240722.0'
+  abseil_version = '~> 1.20250127.1'
 
   # When creating a dynamic framework, name it grpc.framework instead of gRPC-Core.framework.
   # This lets users write their includes like `#include <grpc/grpc.h>` as opposed to `#include
@@ -127,6 +127,7 @@ Pod::Spec.new do |s|
                       'include/grpc/event_engine/extensible.h',
                       'include/grpc/event_engine/internal/memory_allocator_impl.h',
                       'include/grpc/event_engine/internal/slice_cast.h',
+                      'include/grpc/event_engine/internal/write_event.h',
                       'include/grpc/event_engine/memory_allocator.h',
                       'include/grpc/event_engine/memory_request.h',
                       'include/grpc/event_engine/port.h',
@@ -200,7 +201,7 @@ Pod::Spec.new do |s|
     ss.libraries = 'z'
     ss.dependency "#{s.name}/Interface", version
     ss.dependency "#{s.name}/Privacy", version
-    ss.dependency 'BoringSSL-GRPC', '0.0.40'
+    ss.dependency 'BoringSSL-GRPC', '0.0.41'
     ss.dependency 'abseil/algorithm/container', abseil_version
     ss.dependency 'abseil/base/base', abseil_version
     ss.dependency 'abseil/base/config', abseil_version
@@ -208,6 +209,7 @@ Pod::Spec.new do |s|
     ss.dependency 'abseil/base/log_severity', abseil_version
     ss.dependency 'abseil/base/no_destructor', abseil_version
     ss.dependency 'abseil/cleanup/cleanup', abseil_version
+    ss.dependency 'abseil/container/btree', abseil_version
     ss.dependency 'abseil/container/flat_hash_map', abseil_version
     ss.dependency 'abseil/container/flat_hash_set', abseil_version
     ss.dependency 'abseil/container/inlined_vector', abseil_version
@@ -279,6 +281,7 @@ Pod::Spec.new do |s|
                       'src/core/channelz/channelz.h',
                       'src/core/channelz/channelz_registry.cc',
                       'src/core/channelz/channelz_registry.h',
+                      'src/core/channelz/ztrace_collector.h',
                       'src/core/client_channel/backup_poller.cc',
                       'src/core/client_channel/backup_poller.h',
                       'src/core/client_channel/client_channel.cc',
@@ -469,6 +472,7 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/stateful_session/stateful_session_service_config_parser.h',
                       'src/core/ext/transport/chttp2/alpn/alpn.cc',
                       'src/core/ext/transport/chttp2/alpn/alpn.h',
+                      'src/core/ext/transport/chttp2/chttp2_plugin.cc',
                       'src/core/ext/transport/chttp2/client/chttp2_connector.cc',
                       'src/core/ext/transport/chttp2/client/chttp2_connector.h',
                       'src/core/ext/transport/chttp2/server/chttp2_server.cc',
@@ -481,7 +485,6 @@ Pod::Spec.new do |s|
                       'src/core/ext/transport/chttp2/transport/call_tracer_wrapper.h',
                       'src/core/ext/transport/chttp2/transport/chttp2_transport.cc',
                       'src/core/ext/transport/chttp2/transport/chttp2_transport.h',
-                      'src/core/ext/transport/chttp2/transport/context_list_entry.h',
                       'src/core/ext/transport/chttp2/transport/decode_huff.cc',
                       'src/core/ext/transport/chttp2/transport/decode_huff.h',
                       'src/core/ext/transport/chttp2/transport/flow_control.cc',
@@ -516,9 +519,11 @@ Pod::Spec.new do |s|
                       'src/core/ext/transport/chttp2/transport/http2_settings.cc',
                       'src/core/ext/transport/chttp2/transport/http2_settings.h',
                       'src/core/ext/transport/chttp2/transport/http2_status.h',
+                      'src/core/ext/transport/chttp2/transport/http2_ztrace_collector.h',
                       'src/core/ext/transport/chttp2/transport/huffsyms.cc',
                       'src/core/ext/transport/chttp2/transport/huffsyms.h',
                       'src/core/ext/transport/chttp2/transport/internal.h',
+                      'src/core/ext/transport/chttp2/transport/internal_channel_arg_names.h',
                       'src/core/ext/transport/chttp2/transport/legacy_frame.h',
                       'src/core/ext/transport/chttp2/transport/parsing.cc',
                       'src/core/ext/transport/chttp2/transport/ping_abuse_policy.cc',
@@ -1369,6 +1374,7 @@ Pod::Spec.new do |s|
                       'src/core/handshaker/proxy_mapper.h',
                       'src/core/handshaker/proxy_mapper_registry.cc',
                       'src/core/handshaker/proxy_mapper_registry.h',
+                      'src/core/handshaker/security/legacy_secure_endpoint.cc',
                       'src/core/handshaker/security/secure_endpoint.cc',
                       'src/core/handshaker/security/secure_endpoint.h',
                       'src/core/handshaker/security/security_handshaker.cc',
@@ -1422,7 +1428,9 @@ Pod::Spec.new do |s|
                       'src/core/lib/event_engine/default_event_engine_factory.h',
                       'src/core/lib/event_engine/event_engine.cc',
                       'src/core/lib/event_engine/event_engine_context.h',
+                      'src/core/lib/event_engine/extensions/blocking_dns.h',
                       'src/core/lib/event_engine/extensions/can_track_errors.h',
+                      'src/core/lib/event_engine/extensions/channelz.h',
                       'src/core/lib/event_engine/extensions/chaotic_good_extension.h',
                       'src/core/lib/event_engine/extensions/iomgr_compatible.h',
                       'src/core/lib/event_engine/extensions/supports_fd.h',
@@ -1562,8 +1570,6 @@ Pod::Spec.new do |s|
                       'src/core/lib/iomgr/event_engine_shims/tcp_client.h',
                       'src/core/lib/iomgr/exec_ctx.cc',
                       'src/core/lib/iomgr/exec_ctx.h',
-                      'src/core/lib/iomgr/executor.cc',
-                      'src/core/lib/iomgr/executor.h',
                       'src/core/lib/iomgr/fork_posix.cc',
                       'src/core/lib/iomgr/fork_windows.cc',
                       'src/core/lib/iomgr/internal_errqueue.cc',
@@ -1879,6 +1885,7 @@ Pod::Spec.new do |s|
                       'src/core/resolver/xds/xds_dependency_manager.h',
                       'src/core/resolver/xds/xds_resolver.cc',
                       'src/core/resolver/xds/xds_resolver_attributes.h',
+                      'src/core/server/add_port.cc',
                       'src/core/server/server.cc',
                       'src/core/server/server.h',
                       'src/core/server/server_call_tracer_filter.cc',
@@ -1899,6 +1906,9 @@ Pod::Spec.new do |s|
                       'src/core/service_config/service_config_parser.h',
                       'src/core/telemetry/call_tracer.cc',
                       'src/core/telemetry/call_tracer.h',
+                      'src/core/telemetry/context_list_entry.h',
+                      'src/core/telemetry/default_tcp_tracer.cc',
+                      'src/core/telemetry/default_tcp_tracer.h',
                       'src/core/telemetry/histogram_view.cc',
                       'src/core/telemetry/histogram_view.h',
                       'src/core/telemetry/metrics.cc',
@@ -1907,9 +1917,13 @@ Pod::Spec.new do |s|
                       'src/core/telemetry/stats.h',
                       'src/core/telemetry/stats_data.cc',
                       'src/core/telemetry/stats_data.h',
+                      'src/core/telemetry/tcp_tracer.cc',
                       'src/core/telemetry/tcp_tracer.h',
                       'src/core/transport/auth_context.cc',
                       'src/core/transport/auth_context.h',
+                      'src/core/transport/endpoint_transport.h',
+                      'src/core/transport/endpoint_transport_client_channel_factory.cc',
+                      'src/core/transport/endpoint_transport_client_channel_factory.h',
                       'src/core/tsi/alts/crypt/aes_gcm.cc',
                       'src/core/tsi/alts/crypt/gsec.cc',
                       'src/core/tsi/alts/crypt/gsec.h',
@@ -1994,6 +2008,7 @@ Pod::Spec.new do |s|
                       'src/core/util/examine_stack.h',
                       'src/core/util/fork.cc',
                       'src/core/util/fork.h',
+                      'src/core/util/function_signature.h',
                       'src/core/util/gcp_metadata_query.cc',
                       'src/core/util/gcp_metadata_query.h',
                       'src/core/util/gethostname.h',
@@ -2068,6 +2083,8 @@ Pod::Spec.new do |s|
                       'src/core/util/ref_counted_string.cc',
                       'src/core/util/ref_counted_string.h',
                       'src/core/util/ring_buffer.h',
+                      'src/core/util/shared_bit_gen.cc',
+                      'src/core/util/shared_bit_gen.h',
                       'src/core/util/single_set_ptr.h',
                       'src/core/util/sorted_pack.h',
                       'src/core/util/spinlock.h',
@@ -2461,6 +2478,7 @@ Pod::Spec.new do |s|
                               'src/core/channelz/channel_trace.h',
                               'src/core/channelz/channelz.h',
                               'src/core/channelz/channelz_registry.h',
+                              'src/core/channelz/ztrace_collector.h',
                               'src/core/client_channel/backup_poller.h',
                               'src/core/client_channel/client_channel.h',
                               'src/core/client_channel/client_channel_args.h',
@@ -2560,7 +2578,6 @@ Pod::Spec.new do |s|
                               'src/core/ext/transport/chttp2/transport/bin_encoder.h',
                               'src/core/ext/transport/chttp2/transport/call_tracer_wrapper.h',
                               'src/core/ext/transport/chttp2/transport/chttp2_transport.h',
-                              'src/core/ext/transport/chttp2/transport/context_list_entry.h',
                               'src/core/ext/transport/chttp2/transport/decode_huff.h',
                               'src/core/ext/transport/chttp2/transport/flow_control.h',
                               'src/core/ext/transport/chttp2/transport/frame.h',
@@ -2579,8 +2596,10 @@ Pod::Spec.new do |s|
                               'src/core/ext/transport/chttp2/transport/hpack_parser_table.h',
                               'src/core/ext/transport/chttp2/transport/http2_settings.h',
                               'src/core/ext/transport/chttp2/transport/http2_status.h',
+                              'src/core/ext/transport/chttp2/transport/http2_ztrace_collector.h',
                               'src/core/ext/transport/chttp2/transport/huffsyms.h',
                               'src/core/ext/transport/chttp2/transport/internal.h',
+                              'src/core/ext/transport/chttp2/transport/internal_channel_arg_names.h',
                               'src/core/ext/transport/chttp2/transport/legacy_frame.h',
                               'src/core/ext/transport/chttp2/transport/ping_abuse_policy.h',
                               'src/core/ext/transport/chttp2/transport/ping_callbacks.h',
@@ -3118,7 +3137,9 @@ Pod::Spec.new do |s|
                               'src/core/lib/event_engine/default_event_engine.h',
                               'src/core/lib/event_engine/default_event_engine_factory.h',
                               'src/core/lib/event_engine/event_engine_context.h',
+                              'src/core/lib/event_engine/extensions/blocking_dns.h',
                               'src/core/lib/event_engine/extensions/can_track_errors.h',
+                              'src/core/lib/event_engine/extensions/channelz.h',
                               'src/core/lib/event_engine/extensions/chaotic_good_extension.h',
                               'src/core/lib/event_engine/extensions/iomgr_compatible.h',
                               'src/core/lib/event_engine/extensions/supports_fd.h',
@@ -3196,7 +3217,6 @@ Pod::Spec.new do |s|
                               'src/core/lib/iomgr/event_engine_shims/endpoint.h',
                               'src/core/lib/iomgr/event_engine_shims/tcp_client.h',
                               'src/core/lib/iomgr/exec_ctx.h',
-                              'src/core/lib/iomgr/executor.h',
                               'src/core/lib/iomgr/internal_errqueue.h',
                               'src/core/lib/iomgr/iocp_windows.h',
                               'src/core/lib/iomgr/iomgr.h',
@@ -3372,12 +3392,16 @@ Pod::Spec.new do |s|
                               'src/core/service_config/service_config_impl.h',
                               'src/core/service_config/service_config_parser.h',
                               'src/core/telemetry/call_tracer.h',
+                              'src/core/telemetry/context_list_entry.h',
+                              'src/core/telemetry/default_tcp_tracer.h',
                               'src/core/telemetry/histogram_view.h',
                               'src/core/telemetry/metrics.h',
                               'src/core/telemetry/stats.h',
                               'src/core/telemetry/stats_data.h',
                               'src/core/telemetry/tcp_tracer.h',
                               'src/core/transport/auth_context.h',
+                              'src/core/transport/endpoint_transport.h',
+                              'src/core/transport/endpoint_transport_client_channel_factory.h',
                               'src/core/tsi/alts/crypt/gsec.h',
                               'src/core/tsi/alts/frame_protector/alts_counter.h',
                               'src/core/tsi/alts/frame_protector/alts_crypter.h',
@@ -3426,6 +3450,7 @@ Pod::Spec.new do |s|
                               'src/core/util/event_log.h',
                               'src/core/util/examine_stack.h',
                               'src/core/util/fork.h',
+                              'src/core/util/function_signature.h',
                               'src/core/util/gcp_metadata_query.h',
                               'src/core/util/gethostname.h',
                               'src/core/util/glob.h',
@@ -3462,6 +3487,7 @@ Pod::Spec.new do |s|
                               'src/core/util/ref_counted_ptr.h',
                               'src/core/util/ref_counted_string.h',
                               'src/core/util/ring_buffer.h',
+                              'src/core/util/shared_bit_gen.h',
                               'src/core/util/single_set_ptr.h',
                               'src/core/util/sorted_pack.h',
                               'src/core/util/spinlock.h',

gRPC-ProtoRPC.podspec

@@ -21,7 +21,7 @@
 
 Pod::Spec.new do |s|
   s.name     = 'gRPC-ProtoRPC'
-  version = '1.72.1'
+  version = '1.73.1'
   s.version  = version
   s.summary  = 'RPC library for Protocol Buffers, based on gRPC'
   s.homepage = 'https://grpc.io'

gRPC-RxLibrary.podspec

@@ -21,7 +21,7 @@
 
 Pod::Spec.new do |s|
   s.name     = 'gRPC-RxLibrary'
-  version = '1.72.1'
+  version = '1.73.1'
   s.version  = version
   s.summary  = 'Reactive Extensions library for iOS/OSX.'
   s.homepage = 'https://grpc.io'

gRPC.podspec

@@ -20,7 +20,7 @@
 
 Pod::Spec.new do |s|
   s.name     = 'gRPC'
-  version = '1.72.1'
+  version = '1.73.1'
   s.version  = version
   s.summary  = 'gRPC client library for iOS/OSX'
   s.homepage = 'https://grpc.io'

include/grpc/event_engine/event_engine.h

@@ -16,11 +16,14 @@
 
 #include <grpc/event_engine/endpoint_config.h>
 #include <grpc/event_engine/extensible.h>
+#include <grpc/event_engine/internal/write_event.h>
 #include <grpc/event_engine/memory_allocator.h>
 #include <grpc/event_engine/port.h>
 #include <grpc/event_engine/slice_buffer.h>
 #include <grpc/support/port_platform.h>
 
+#include <bitset>
+#include <initializer_list>
 #include <vector>
 
 #include "absl/functional/any_invocable.h"
@@ -180,13 +183,26 @@ class EventEngine : public std::enable_shared_from_this<EventEngine>,
     /// EventEngine Endpoint Read API  call.
     ///
     /// Passed as argument to an Endpoint \a Read
-    struct ReadArgs {
+    class ReadArgs final {
+     public:
+      ReadArgs() = default;
+      ReadArgs(const ReadArgs&) = delete;
+      ReadArgs& operator=(const ReadArgs&) = delete;
+      ReadArgs(ReadArgs&&) = default;
+      ReadArgs& operator=(ReadArgs&&) = default;
+
       // A suggestion to the endpoint implementation to read at-least the
       // specified number of bytes over the network connection before marking
       // the endpoint read operation as complete. gRPC may use this argument
       // to minimize the number of endpoint read API calls over the lifetime
       // of a connection.
-      int64_t read_hint_bytes;
+      void set_read_hint_bytes(int64_t read_hint_bytes) {
+        read_hint_bytes_ = read_hint_bytes;
+      }
+      int64_t read_hint_bytes() const { return read_hint_bytes_; }
+
+     private:
+      int64_t read_hint_bytes_ = 1;
     };
     /// Reads data from the Endpoint.
     ///
@@ -212,20 +228,110 @@ class EventEngine : public std::enable_shared_from_this<EventEngine>,
     /// statuses to \a on_read. For example, callbacks might expect to receive
     /// CANCELLED on endpoint shutdown.
     virtual bool Read(absl::AnyInvocable<void(absl::Status)> on_read,
-                      SliceBuffer* buffer, const ReadArgs* args) = 0;
+                      SliceBuffer* buffer, ReadArgs args) = 0;
+    //// The set of write events that can be reported by an Endpoint.
+    using WriteEvent = ::grpc_event_engine::experimental::internal::WriteEvent;
+    /// An output WriteMetric consists of a key and a value.
+    /// The space of keys can be queried from the endpoint via the
+    /// \a AllWriteMetrics, \a GetMetricName and \a GetMetricKey APIs.
+    /// The value is an int64_t that is implementation-defined. Check with the
+    /// endpoint implementation documentation for the semantics of each metric.
+    struct WriteMetric {
+      size_t key;
+      int64_t value;
+    };
+    using WriteEventCallback = absl::AnyInvocable<void(
+        WriteEvent, absl::Time, std::vector<WriteMetric>) const>;
+    // A bitmask of the events that the caller is interested in.
+    // Each bit corresponds to an entry in WriteEvent.
+    using WriteEventSet = std::bitset<static_cast<int>(WriteEvent::kCount)>;
+    // A sink to receive write events.
+    // The requested metrics are the keys of the metrics that the caller is
+    // interested in. The on_event callback will be called on each event
+    // requested.
+    class WriteEventSink final {
+     public:
+      WriteEventSink(absl::Span<const size_t> requested_metrics,
+                     std::initializer_list<WriteEvent> requested_events,
+                     WriteEventCallback on_event)
+          : requested_metrics_(requested_metrics),
+            on_event_(std::move(on_event)) {
+        for (auto event : requested_events) {
+          requested_events_mask_.set(static_cast<int>(event));
+        }
+      }
+
+      absl::Span<const size_t> requested_metrics() const {
+        return requested_metrics_;
+      }
+
+      bool requested_event(WriteEvent event) const {
+        return requested_events_mask_.test(static_cast<int>(event));
+      }
+
+      WriteEventSet requested_events_mask() const {
+        return requested_events_mask_;
+      }
+
+      WriteEventCallback TakeEventCallback() { return std::move(on_event_); }
+
+     private:
+      absl::Span<const size_t> requested_metrics_;
+      WriteEventSet requested_events_mask_;
+      // The callback to be called on each event.
+      WriteEventCallback on_event_;
+    };
     /// A struct representing optional arguments that may be provided to an
     /// EventEngine Endpoint Write API call.
     ///
     /// Passed as argument to an Endpoint \a Write
-    struct WriteArgs {
+    class WriteArgs final {
+     public:
+      WriteArgs() = default;
+      WriteArgs(const WriteArgs&) = delete;
+      WriteArgs& operator=(const WriteArgs&) = delete;
+      WriteArgs(WriteArgs&&) = default;
+      WriteArgs& operator=(WriteArgs&&) = default;
+
+      // A sink to receive write events.
+      std::optional<WriteEventSink> TakeMetricsSink() {
+        auto sink = std::move(metrics_sink_);
+        metrics_sink_.reset();
+        return sink;
+      }
+
+      bool has_metrics_sink() const { return metrics_sink_.has_value(); }
+
+      void set_metrics_sink(WriteEventSink sink) {
+        metrics_sink_ = std::move(sink);
+      }
+
       // Represents private information that may be passed by gRPC for
       // select endpoints expected to be used only within google.
-      void* google_specific = nullptr;
+      // TODO(ctiller): Remove this method once all callers are migrated to
+      // metrics sink.
+      void* GetDeprecatedAndDiscouragedGoogleSpecificPointer() {
+        return google_specific_;
+      }
+
+      void SetDeprecatedAndDiscouragedGoogleSpecificPointer(void* pointer) {
+        google_specific_ = pointer;
+      }
+
       // A suggestion to the endpoint implementation to group data to be written
       // into frames of the specified max_frame_size. gRPC may use this
       // argument to dynamically control the max sizes of frames sent to a
       // receiver in response to high receiver memory pressure.
-      int64_t max_frame_size;
+      int64_t max_frame_size() const { return max_frame_size_; }
+
+      void set_max_frame_size(int64_t max_frame_size) {
+        max_frame_size_ = max_frame_size;
+      }
+
+     private:
+      std::optional<WriteEventSink> metrics_sink_;
+      void* google_specific_ = nullptr;
+      int64_t max_frame_size_ = 1024 * 1024;
     };
     /// Writes data out on the connection.
     ///
@@ -248,11 +354,22 @@ class EventEngine : public std::enable_shared_from_this<EventEngine>,
     /// statuses to \a on_writable. For example, callbacks might expect to
     /// receive CANCELLED on endpoint shutdown.
     virtual bool Write(absl::AnyInvocable<void(absl::Status)> on_writable,
-                       SliceBuffer* data, const WriteArgs* args) = 0;
+                       SliceBuffer* data, WriteArgs args) = 0;
     /// Returns an address in the format described in DNSResolver. The returned
     /// values are expected to remain valid for the life of the Endpoint.
     virtual const ResolvedAddress& GetPeerAddress() const = 0;
     virtual const ResolvedAddress& GetLocalAddress() const = 0;
+    /// Returns the list of write metrics that the endpoint supports.
+    /// The keys are used to identify the metrics in the GetMetricName and
+    /// GetMetricKey APIs. The current value of the metric can be queried by
+    /// adding a WriteEventSink to the WriteArgs of a Write call.
+    virtual std::vector<size_t> AllWriteMetrics() = 0;
+    /// Returns the name of the write metric with the given key.
+    /// If the key is not found, returns std::nullopt.
+    virtual std::optional<absl::string_view> GetMetricName(size_t key) = 0;
+    /// Returns the key of the write metric with the given name.
+    /// If the name is not found, returns std::nullopt.
+    virtual std::optional<size_t> GetMetricKey(absl::string_view name) = 0;
   };
 
   /// Called when a new connection is established.
@@ -334,7 +451,7 @@ class EventEngine : public std::enable_shared_from_this<EventEngine>,
   /// when the object is destroyed and all pending callbacks will be called
   /// shortly. If cancellation races with request completion, implementations
   /// may choose to either cancel or satisfy the request.
-  class DNSResolver {
+  class DNSResolver : public Extensible {
    public:
     /// Optional configuration for DNSResolvers.
     struct ResolverOptions {

include/grpc/event_engine/internal/write_event.h

@@ -0,0 +1,34 @@
+// Copyright 2022 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef GRPC_EVENT_ENGINE_INTERNAL_WRITE_EVENT_H
+#define GRPC_EVENT_ENGINE_INTERNAL_WRITE_EVENT_H
+
+namespace grpc_event_engine::experimental::internal {
+
+// Use of this enum via this name is internal to gRPC.
+// API users should get this enumeration via the
+// EventEngine::Endpoint::WriteEvent.
+enum class WriteEvent {
+  kSendMsg,
+  kScheduled,
+  kSent,
+  kAcked,
+  kClosed,
+  kCount  // Must be last.
+};
+
+}  // namespace grpc_event_engine::experimental::internal
+
+#endif  // GRPC_EVENT_ENGINE_INTERNAL_WRITE_EVENT_H

include/grpc/impl/channel_arg_names.h

@@ -51,11 +51,13 @@
  * server will close the connection. Int valued, milliseconds. INT_MAX means
  * unlimited. Defaults to INT_MAX. */
 #define GRPC_ARG_MAX_CONNECTION_IDLE_MS "grpc.max_connection_idle_ms"
-/** Maximum time that a channel may exist. Int valued, milliseconds.
- * INT_MAX means unlimited. Defaults to INT_MAX. */
+/** Maximum amount of time in milliseconds that a connection may exist before it
+ * will be gracefully shut down. Refer
+ * https://github.com/grpc/proposal/blob/master/A9-server-side-conn-mgt.md for
+ * more details. Int valued, defaults to INT_MAX (disabled). */
 #define GRPC_ARG_MAX_CONNECTION_AGE_MS "grpc.max_connection_age_ms"
-/** Grace period after the channel reaches its max age. Int valued,
-   milliseconds. INT_MAX means unlimited. Defaults to INT_MAX. */
+/** Grace period in milliseconds after connection reaches its max age for
+ * outstanding RPCs to complete. Int valued, defaults to INT_MAX (disabled). */
 #define GRPC_ARG_MAX_CONNECTION_AGE_GRACE_MS "grpc.max_connection_age_grace_ms"
 /** Timeout after the last RPC finishes on the client channel at which the
  * channel goes back into IDLE state. Int valued, milliseconds. INT_MAX means
@@ -168,13 +170,19 @@
 /** Secondary user agent: goes at the end of the user-agent metadata
     sent on each request. A string. */
 #define GRPC_ARG_SECONDARY_USER_AGENT_STRING "grpc.secondary_user_agent"
-/** The minimum time between subsequent connection attempts, in ms. Defaults to
- * 20 seconds. */
+/** The minimum time between subsequent connection attempts, in ms. Refer to
+ * MIN_CONNECT_TIMEOUT from
+ * https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md. Defaults
+ * to 20 seconds. */
 #define GRPC_ARG_MIN_RECONNECT_BACKOFF_MS "grpc.min_reconnect_backoff_ms"
-/** The maximum time between subsequent connection attempts, in ms. Defaults to
- * 120 seconds. */
+/** The maximum time between subsequent connection attempts, in ms. Refer to
+ * MAX_BACKOFF from
+ * https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md. Defaults
+ * to 120 seconds.  */
 #define GRPC_ARG_MAX_RECONNECT_BACKOFF_MS "grpc.max_reconnect_backoff_ms"
-/** The time between the first and second connection attempts, in ms. Defaults
+/** The time between the first and second connection attempts, in ms. Refer to
+ * INITIAL_BACKOFF from
+ * https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md. Defaults
  * to 1 second. */
 #define GRPC_ARG_INITIAL_RECONNECT_BACKOFF_MS \
   "grpc.initial_reconnect_backoff_ms"

include/grpc/impl/compression_types.h

@@ -41,8 +41,9 @@ extern "C" {
  * Its value is an int from the \a grpc_compression_algorithm enum. */
 #define GRPC_COMPRESSION_CHANNEL_DEFAULT_ALGORITHM \
   "grpc.default_compression_algorithm"
-/** Default compression level for the channel.
- * Its value is an int from the \a grpc_compression_level enum. */
+/** Set the default compression level for the channel.
+ * Valid values are defined by the enum type grpc_compression_level, defaults to
+ * GRPC_COMPRESS_LEVEL_NONE. */
 #define GRPC_COMPRESSION_CHANNEL_DEFAULT_LEVEL "grpc.default_compression_level"
 /** Compression algorithms supported by the channel.
  * Its value is a bitset (an int). Bits correspond to algorithms in \a

include/grpc/impl/slice_type.h

@@ -73,7 +73,7 @@ struct grpc_slice {
   } data;
 };
 
-#define GRPC_SLICE_BUFFER_INLINE_ELEMENTS 6
+#define GRPC_SLICE_BUFFER_INLINE_ELEMENTS 3
 
 /** Represents an expandable array of slices, to be interpreted as a
    single item. */

include/grpc/support/json.h

@@ -22,6 +22,7 @@
 
 #include <map>
 #include <string>
+#include <type_traits>
 #include <utility>
 #include <variant>
 #include <vector>
@@ -72,27 +73,8 @@ class Json {
     json.value_ = NumberValue{std::move(str)};
     return json;
   }
-  static Json FromNumber(int32_t value) {
-    Json json;
-    json.value_ = NumberValue{absl::StrCat(value)};
-    return json;
-  }
-  static Json FromNumber(uint32_t value) {
-    Json json;
-    json.value_ = NumberValue{absl::StrCat(value)};
-    return json;
-  }
-  static Json FromNumber(int64_t value) {
-    Json json;
-    json.value_ = NumberValue{absl::StrCat(value)};
-    return json;
-  }
-  static Json FromNumber(uint64_t value) {
-    Json json;
-    json.value_ = NumberValue{absl::StrCat(value)};
-    return json;
-  }
-  static Json FromNumber(double value) {
+  template <typename T>
+  static std::enable_if_t<std::is_arithmetic_v<T>, Json> FromNumber(T value) {
     Json json;
     json.value_ = NumberValue{absl::StrCat(value)};
     return json;

include/grpc/support/port_platform.h

@@ -26,17 +26,20 @@
 #define GRPC_DEPRECATED(reason)
 #endif  // __cplusplus >= 201402L
 
+#ifndef GPR_DISABLE_ABSEIL_SYNC
 /*
  * Defines GPR_ABSEIL_SYNC to use synchronization features from Abseil
+ *
+ * You can opt for gRPC's native synchronization by enabling
+ * GPR_DISABLE_ABSEIL_SYNC. However, this flag is temporary and will be
+ * removed once the Abseil synchronization is stabilized.
+ * If you encounter any issues with this feature, please report them
+ * by filing a bug at https://github.com/grpc/grpc.
  */
 #ifndef GPR_ABSEIL_SYNC
-#if defined(__APPLE__)
-// This is disabled on Apple platforms because macos/grpc_basictests_c_cpp
-// fails with this. https://github.com/grpc/grpc/issues/23661
-#else
 #define GPR_ABSEIL_SYNC 1
-#endif
 #endif  // GPR_ABSEIL_SYNC
+#endif  // GPR_DISABLE_ABSEIL_SYNC
 
 /* Get windows.h included everywhere (we need it) */
 #if defined(_WIN64) || defined(WIN64) || defined(_WIN32) || defined(WIN32)

include/grpcpp/impl/server_callback_handlers.h

@@ -116,8 +116,8 @@ class CallbackUnaryHandler : public grpc::internal::MethodHandler {
       // A callback that only contains a call to MaybeDone can be run as an
       // inline callback regardless of whether or not OnDone is inlineable
       // because if the actual OnDone callback needs to be scheduled, MaybeDone
-      // is responsible for dispatching to an executor thread if needed. Thus,
-      // when setting up the finish_tag_, we can set its own callback to
+      // is responsible for dispatching to an EventEngine thread if needed.
+      // Thus, when setting up the finish_tag_, we can set its own callback to
       // inlineable.
       finish_tag_.Set(
           call_.call(),
@@ -152,9 +152,9 @@ class CallbackUnaryHandler : public grpc::internal::MethodHandler {
       this->Ref();
       // The callback for this function should not be marked inline because it
       // is directly invoking a user-controlled reaction
-      // (OnSendInitialMetadataDone). Thus it must be dispatched to an executor
-      // thread. However, any OnDone needed after that can be inlined because it
-      // is already running on an executor thread.
+      // (OnSendInitialMetadataDone). Thus it must be dispatched to an
+      // EventEngine thread. However, any OnDone needed after that can be
+      // inlined because it is already running on an EventEngine thread.
       meta_tag_.Set(
           call_.call(),
           [this](bool ok) {
@@ -340,7 +340,7 @@ class CallbackClientStreamingHandler : public grpc::internal::MethodHandler {
       this->Ref();
       // The callback for this function should not be inlined because it invokes
       // a user-controlled reaction, but any resulting OnDone can be inlined in
-      // the executor to which this callback is dispatched.
+      // the EventEngine thread to which this callback is dispatched.
       meta_tag_.Set(
           call_.call(),
           [this](bool ok) {
@@ -380,7 +380,7 @@ class CallbackClientStreamingHandler : public grpc::internal::MethodHandler {
       reactor_.store(reactor, std::memory_order_relaxed);
       // The callback for this function should not be inlined because it invokes
       // a user-controlled reaction, but any resulting OnDone can be inlined in
-      // the executor to which this callback is dispatched.
+      // the EventEngine thread to which this callback is dispatched.
       read_tag_.Set(
           call_.call(),
           [this, reactor](bool ok) {
@@ -544,7 +544,7 @@ class CallbackServerStreamingHandler : public grpc::internal::MethodHandler {
       this->Ref();
       // The callback for this function should not be inlined because it invokes
       // a user-controlled reaction, but any resulting OnDone can be inlined in
-      // the executor to which this callback is dispatched.
+      // the EventEngine thread to which this callback is dispatched.
       meta_tag_.Set(
           call_.call(),
           [this](bool ok) {
@@ -607,7 +607,7 @@ class CallbackServerStreamingHandler : public grpc::internal::MethodHandler {
       reactor_.store(reactor, std::memory_order_relaxed);
       // The callback for this function should not be inlined because it invokes
       // a user-controlled reaction, but any resulting OnDone can be inlined in
-      // the executor to which this callback is dispatched.
+      // the EventEngine thread to which this callback is dispatched.
       write_tag_.Set(
           call_.call(),
           [this, reactor](bool ok) {
@@ -756,7 +756,7 @@ class CallbackBidiHandler : public grpc::internal::MethodHandler {
       this->Ref();
       // The callback for this function should not be inlined because it invokes
       // a user-controlled reaction, but any resulting OnDone can be inlined in
-      // the executor to which this callback is dispatched.
+      // the EventEngine thread to which this callback is dispatched.
       meta_tag_.Set(
           call_.call(),
           [this](bool ok) {
@@ -821,7 +821,7 @@ class CallbackBidiHandler : public grpc::internal::MethodHandler {
       reactor_.store(reactor, std::memory_order_relaxed);
       // The callbacks for these functions should not be inlined because they
       // invoke user-controlled reactions, but any resulting OnDones can be
-      // inlined in the executor to which a callback is dispatched.
+      // inlined in the EventEngine thread to which a callback is dispatched.
       write_tag_.Set(
           call_.call(),
           [this, reactor](bool ok) {

include/grpcpp/server_context.h

@@ -501,9 +501,9 @@ class ServerContextBase {
     void OnCancel() override {}
     void OnDone() override {}
     // Override InternalInlineable for this class since its reactions are
-    // trivial and thus do not need to be run from the executor (triggering a
-    // thread hop). This should only be used by internal reactors (thus the
-    // name) and not by user application code.
+    // trivial and thus do not need to be run from the EventEngine (potentially
+    // triggering a thread hop). This should only be used by internal reactors
+    // (thus the name) and not by user application code.
     bool InternalInlineable() override { return true; }
   };
 

include/grpcpp/support/client_callback.h

@@ -636,8 +636,8 @@ class ClientCallbackReaderWriterImpl
   // like StartCall or RemoveHold. If this is the last operation or hold on this
   // object, it will invoke the OnDone reaction. If MaybeFinish was called from
   // a reaction, it can call OnDone directly. If not, it would need to schedule
-  // OnDone onto an executor thread to avoid the possibility of deadlocking with
-  // any locks in the user code that invoked it.
+  // OnDone onto an EventEngine thread to avoid the possibility of deadlocking
+  // with any locks in the user code that invoked it.
   void MaybeFinish(bool from_reaction) {
     if (GPR_UNLIKELY(callbacks_outstanding_.fetch_sub(
                          1, std::memory_order_acq_rel) == 1)) {

include/grpcpp/support/server_callback.h

@@ -56,7 +56,7 @@ class ServerReactor {
   virtual void OnCancel() = 0;
 
   // The following is not API. It is for internal use only and specifies whether
-  // all reactions of this Reactor can be run without an extra executor
+  // all reactions of this Reactor can be run without extra EventEngine
   // scheduling. This should only be used for internally-defined reactors with
   // trivial reactions.
   virtual bool InternalInlineable() { return false; }
@@ -90,7 +90,7 @@ class ServerCallbackCall {
   // advance (used for the ServerContext CompletionOp), and one for where we
   // know the inlineability of the OnDone reaction. You should set the inline
   // flag to true if either the Reactor is InternalInlineable() or if this
-  // callback is already being forced to run dispatched to an executor
+  // callback is already being forced to run dispatched to an EventEngine thread
   // (typically because it contains additional work than just the MaybeDone).
 
   void MaybeDone() {
@@ -141,12 +141,12 @@ class ServerCallbackCall {
   // ever invoked on a fully-Unref'fed ServerCallbackCall.
   virtual void CallOnDone() = 0;
 
-  // If the OnDone reaction is inlineable, execute it inline. Otherwise send it
-  // to an executor.
+  // If the OnDone reaction is inlineable, execute it inline. Otherwise run it
+  // async on EventEngine.
   void ScheduleOnDone(bool inline_ondone);
 
-  // If the OnCancel reaction is inlineable, execute it inline. Otherwise send
-  // it to an executor.
+  // If the OnCancel reaction is inlineable, execute it inline. Otherwise run it
+  // async on EventEngine.
   void CallOnCancel(ServerReactor* reactor);
 
   // Implement the cancellation constraint counter. Return true if OnCancel

include/grpcpp/version_info.h

@@ -19,9 +19,9 @@
 #define GRPCPP_VERSION_INFO_H
 
 #define GRPC_CPP_VERSION_MAJOR 1
-#define GRPC_CPP_VERSION_MINOR 72
+#define GRPC_CPP_VERSION_MINOR 73
 #define GRPC_CPP_VERSION_PATCH 1
 #define GRPC_CPP_VERSION_TAG ""
-#define GRPC_CPP_VERSION_STRING "1.72.1"
+#define GRPC_CPP_VERSION_STRING "1.73.1"
 
-#endif  // GRPCPP_VERSION_INFO_H
+#endif // GRPCPP_VERSION_INFO_H

scripts/extract-grpc-ios-files.py

@@ -28,10 +28,14 @@ targets = (
     'grpc_authorization_provider',
     'gpr',
     'upb_base_lib',
+    'upb_hash_lib',
+    'upb_lex_lib',
     'upb_mem_lib',
     'upb_message_lib',
     'upb_mini_descriptor_lib',
+    'upb_mini_table_lib',
     'upb_json_lib',
+    'upb_reflection_lib',
     'upb_textformat_lib',
     'upb_wire_lib',
     'utf8_range_lib',

src/core/call/call_filters.h

@@ -1316,7 +1316,7 @@ template <typename T>
 GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION inline OperationExecutor<
     T>::~OperationExecutor() {
   if (promise_data_ != nullptr) {
-    ops_->early_destroy(promise_data_);
+    if (ops_ != end_ops_) ops_->early_destroy(promise_data_);
     gpr_free_aligned(promise_data_);
   }
 }
@@ -1349,7 +1349,10 @@ OperationExecutor<T>::InitStep(T input, void* call_data) {
         ops_->promise_init(promise_data_, Offset(call_data, ops_->call_offset),
                            ops_->channel_data, std::move(input));
     if (auto* r = p.value_if_ready()) {
-      if (r->ok == nullptr) return std::move(*r);
+      if (r->ok == nullptr) {
+        ops_ = end_ops_;
+        return std::move(*r);
+      }
       input = std::move(r->ok);
       ++ops_;
       continue;
@@ -1443,20 +1446,20 @@ constexpr bool MethodHasChannelAccess<R (T::*)()> = false;
 template <typename T, typename R, typename A, typename C>
 constexpr bool MethodHasChannelAccess<R (T::*)(A, C)> = true;
 
-template <auto... Ts>
-constexpr bool AnyMethodHasChannelAccess =
-    (MethodHasChannelAccess<decltype(Ts)> || ...);
+template <typename... Ts>
+constexpr bool AnyMethodHasChannelAccess = (MethodHasChannelAccess<Ts> || ...);
 
 // Composite for a given channel type to determine if any of its interceptors
 // fall into this category: later code should use this.
 template <typename Derived>
 inline constexpr bool CallHasChannelAccess() {
-  return AnyMethodHasChannelAccess<&Derived::Call::OnClientInitialMetadata,
-                                   &Derived::Call::OnClientToServerMessage,
-                                   &Derived::Call::OnServerInitialMetadata,
-                                   &Derived::Call::OnServerToClientMessage,
-                                   &Derived::Call::OnServerTrailingMetadata,
-                                   &Derived::Call::OnFinalize>;
+  return AnyMethodHasChannelAccess<
+      decltype(&Derived::Call::OnClientInitialMetadata),
+      decltype(&Derived::Call::OnClientToServerMessage),
+      decltype(&Derived::Call::OnServerInitialMetadata),
+      decltype(&Derived::Call::OnServerToClientMessage),
+      decltype(&Derived::Call::OnServerTrailingMetadata),
+      decltype(&Derived::Call::OnFinalize)>;
 }
 }  // namespace filters_detail
 
@@ -1667,7 +1670,9 @@ class CallFilters {
         }
         return FinishStep(executor_.Start(
             &(stack_current_->stack->data_.*layout),
-            std::move(filters_->*input_location), filters_->call_data_));
+            std::move(filters_->*input_location),
+            filters_detail::Offset(filters_->call_data_,
+                                   stack_current_->call_data_offset)));
       } else {
         return FinishStep(executor_.Step(filters_->call_data_));
       }
@@ -1684,9 +1689,10 @@ class CallFilters {
           (filters_->call_state_.*on_done)();
           return ValueOrFailure<Output>{std::move(r->ok)};
         }
-        return FinishStep(
-            executor_.Start(&(stack_current_->stack->data_.*layout),
-                            std::move(r->ok), filters_->call_data_));
+        return FinishStep(executor_.Start(
+            &(stack_current_->stack->data_.*layout), std::move(r->ok),
+            filters_detail::Offset(filters_->call_data_,
+                                   stack_current_->call_data_offset)));
       }
       (filters_->call_state_.*on_done)();
       filters_->PushServerTrailingMetadata(std::move(r->error));
@@ -1724,7 +1730,9 @@ class CallFilters {
         }
         return FinishStep(executor_.Start(
             &(stack_current_->stack->data_.*layout),
-            std::move(filters_->*input_location), filters_->call_data_));
+            std::move(filters_->*input_location),
+            filters_detail::Offset(filters_->call_data_,
+                                   stack_current_->call_data_offset)));
       } else {
         return FinishStep(executor_.Step(filters_->call_data_));
       }
@@ -1739,9 +1747,10 @@ class CallFilters {
         if (stack_current_ == stack_end_) {
           return NextMsg{std::move(r->ok), &filters_->call_state_};
         }
-        return FinishStep(
-            executor_.Start(&(stack_current_->stack->data_.*layout),
-                            std::move(r->ok), filters_->call_data_));
+        return FinishStep(executor_.Start(
+            &(stack_current_->stack->data_.*layout), std::move(r->ok),
+            filters_detail::Offset(filters_->call_data_,
+                                   stack_current_->call_data_offset)));
       }
       (filters_->call_state_.*on_done)();
       filters_->PushServerTrailingMetadata(std::move(r->error));

src/core/call/call_spine.h

@@ -144,6 +144,8 @@ class CallSpine final : public Party {
   template <typename StatusType>
   void CancelIfFailed(const StatusType& r) {
     if (!IsStatusOk(r)) {
+      GRPC_TRACE_LOG(call_state, INFO)
+          << "[call_state] spine " << this << " fails: " << r;
       Cancel();
     }
   }

src/core/call/metadata.h

@@ -62,6 +62,16 @@ class ServerMetadataOrHandle {
     return value_;
   }
 
+  ServerMetadataHandle TakeMetadata() && {
+    CHECK(!ok());
+    return std::move(server_metadata_);
+  }
+
+  ValueType TakeValue() && {
+    CHECK(ok());
+    return std::move(value_);
+  }
+
  private:
   ServerMetadataOrHandle(ServerMetadataHandle server_metadata, ValueType value)
       : server_metadata_(std::move(server_metadata)),
@@ -85,6 +95,13 @@ struct FailureStatusCastImpl<ServerMetadataOrHandle<T>, ServerMetadataHandle&> {
   }
 };
 
+template <>
+struct FailureStatusCastImpl<ServerMetadataHandle, ServerMetadataHandle&> {
+  static ServerMetadataHandle Cast(ServerMetadataHandle& t) {
+    return std::move(t);
+  }
+};
+
 template <typename T>
 inline bool IsStatusOk(const ServerMetadataOrHandle<T>& x) {
   return x.ok();

src/core/channelz/channel_trace.cc

@@ -29,7 +29,9 @@
 #include "src/core/channelz/channelz.h"
 #include "src/core/lib/slice/slice.h"
 #include "src/core/lib/slice/slice_internal.h"
+#include "src/core/util/ref_counted_ptr.h"
 #include "src/core/util/string.h"
+#include "src/core/util/sync.h"
 #include "src/core/util/time.h"
 
 namespace grpc_core {
@@ -52,41 +54,8 @@ ChannelTrace::TraceEvent::TraceEvent(Severity severity, const grpc_slice& data)
 
 ChannelTrace::TraceEvent::~TraceEvent() { CSliceUnref(data_); }
 
-namespace {
-
-const char* SeverityString(ChannelTrace::Severity severity) {
-  switch (severity) {
-    case ChannelTrace::Severity::Info:
-      return "CT_INFO";
-    case ChannelTrace::Severity::Warning:
-      return "CT_WARNING";
-    case ChannelTrace::Severity::Error:
-      return "CT_ERROR";
-    default:
-      GPR_UNREACHABLE_CODE(return "CT_UNKNOWN");
-  }
-}
-
-}  // anonymous namespace
-
-Json ChannelTrace::TraceEvent::RenderTraceEvent() const {
-  char* description = grpc_slice_to_c_string(data_);
-  Json::Object object = {
-      {"description", Json::FromString(description)},
-      {"severity", Json::FromString(SeverityString(severity_))},
-      {"timestamp", Json::FromString(gpr_format_timespec(timestamp_))},
-  };
-  gpr_free(description);
-  if (referenced_entity_ != nullptr) {
-    const bool is_channel =
-        (referenced_entity_->type() == BaseNode::EntityType::kTopLevelChannel ||
-         referenced_entity_->type() == BaseNode::EntityType::kInternalChannel);
-    object[is_channel ? "channelRef" : "subchannelRef"] = Json::FromObject({
-        {(is_channel ? "channelId" : "subchannelId"),
-         Json::FromString(absl::StrCat(referenced_entity_->uuid()))},
-    });
-  }
-  return Json::FromObject(std::move(object));
+RefCountedPtr<BaseNode> ChannelTrace::TraceEvent::referenced_entity() const {
+  return referenced_entity_;
 }
 
 //
@@ -115,9 +84,8 @@ void ChannelTrace::AddTraceEventHelper(TraceEvent* new_trace_event) {
   // first event case
   if (head_trace_ == nullptr) {
     head_trace_ = tail_trace_ = new_trace_event;
-  }
-  // regular event add case
-  else {
+  } else {
+    // regular event add case
     tail_trace_->set_next(new_trace_event);
     tail_trace_ = tail_trace_->next();
   }
@@ -151,6 +119,25 @@ void ChannelTrace::AddTraceEventWithReference(
       new TraceEvent(severity, data, std::move(referenced_entity)));
 }
 
+std::string ChannelTrace::TraceEvent::description() const {
+  char* description = grpc_slice_to_c_string(data_);
+  std::string s(description);
+  gpr_free(description);
+  return s;
+}
+
+void ChannelTrace::ForEachTraceEventLocked(
+    absl::FunctionRef<void(gpr_timespec, Severity, std::string,
+                           RefCountedPtr<BaseNode>)>
+        callback) const {
+  TraceEvent* it = head_trace_;
+  while (it != nullptr) {
+    callback(it->timestamp(), it->severity(), it->description(),
+             it->referenced_entity());
+    it = it->next();
+  }
+}
+
 Json ChannelTrace::RenderJson() const {
   // Tracing is disabled if max_event_memory_ == 0.
   if (max_event_memory_ == 0) {
@@ -166,15 +153,36 @@ Json ChannelTrace::RenderJson() const {
         Json::FromString(absl::StrCat(num_events_logged_));
   }
   // Only add in the event list if it is non-empty.
-  if (head_trace_ != nullptr) {
-    Json::Array array;
-    for (TraceEvent* it = head_trace_; it != nullptr; it = it->next()) {
-      array.emplace_back(it->RenderTraceEvent());
+  Json::Array array;
+  ForEachTraceEventLocked([&array](gpr_timespec timestamp, Severity severity,
+                                   std::string description,
+                                   RefCountedPtr<BaseNode> referenced_entity) {
+    Json::Object object = {
+        {"description", Json::FromString(description)},
+        {"severity", Json::FromString(SeverityString(severity))},
+        {"timestamp", Json::FromString(gpr_format_timespec(timestamp))},
+    };
+    if (referenced_entity != nullptr) {
+      const bool is_channel =
+          (referenced_entity->type() ==
+               BaseNode::EntityType::kTopLevelChannel ||
+           referenced_entity->type() == BaseNode::EntityType::kInternalChannel);
+      object[is_channel ? "channelRef" : "subchannelRef"] = Json::FromObject({
+          {(is_channel ? "channelId" : "subchannelId"),
+           Json::FromString(absl::StrCat(referenced_entity->uuid()))},
+      });
     }
+    array.emplace_back(Json::FromObject(std::move(object)));
+  });
+  if (!array.empty()) {
     object["events"] = Json::FromArray(std::move(array));
   }
   return Json::FromObject(std::move(object));
 }
 
+std::string ChannelTrace::creation_timestamp() const {
+  return gpr_format_timespec(time_created_);
+}
+
 }  // namespace channelz
 }  // namespace grpc_core

src/core/channelz/channel_trace.h

@@ -24,6 +24,7 @@
 #include <grpc/support/time.h>
 #include <stddef.h>
 #include <stdint.h>
+#include <sys/types.h>
 
 #include "absl/base/thread_annotations.h"
 #include "src/core/util/json/json.h"
@@ -54,6 +55,19 @@ class ChannelTrace {
     Error
   };
 
+  static const char* SeverityString(ChannelTrace::Severity severity) {
+    switch (severity) {
+      case ChannelTrace::Severity::Info:
+        return "CT_INFO";
+      case ChannelTrace::Severity::Warning:
+        return "CT_WARNING";
+      case ChannelTrace::Severity::Error:
+        return "CT_ERROR";
+      default:
+        GPR_UNREACHABLE_CODE(return "CT_UNKNOWN");
+    }
+  }
+
   // Adds a new trace event to the tracing object
   //
   // NOTE: each ChannelTrace tracks the memory used by its list of trace
@@ -82,6 +96,19 @@ class ChannelTrace {
   // object may incorporate the json before rendering.
   Json RenderJson() const;
 
+  void ForEachTraceEvent(
+      absl::FunctionRef<void(gpr_timespec, Severity, std::string,
+                             RefCountedPtr<BaseNode>)>
+          callback) const {
+    MutexLock lock(&mu_);
+    ForEachTraceEventLocked(callback);
+  }
+  std::string creation_timestamp() const;
+  uint64_t num_events_logged() const {
+    MutexLock lock(&mu_);
+    return num_events_logged_;
+  }
+
  private:
   friend size_t testing::GetSizeofTraceEvent(void);
 
@@ -99,15 +126,15 @@ class ChannelTrace {
 
     ~TraceEvent();
 
-    // Renders the data inside of this TraceEvent into a json object. This is
-    // used by the ChannelTrace, when it is rendering itself.
-    Json RenderTraceEvent() const;
-
     // set and get for the next_ pointer.
     TraceEvent* next() const { return next_; }
     void set_next(TraceEvent* next) { next_ = next; }
 
     size_t memory_usage() const { return memory_usage_; }
+    gpr_timespec timestamp() const { return timestamp_; }
+    Severity severity() const { return severity_; }
+    std::string description() const;
+    RefCountedPtr<BaseNode> referenced_entity() const;
 
    private:
     const gpr_timespec timestamp_;
@@ -121,6 +148,10 @@ class ChannelTrace {
 
   // Internal helper to add and link in a trace event
   void AddTraceEventHelper(TraceEvent* new_trace_event);
+  void ForEachTraceEventLocked(
+      absl::FunctionRef<void(gpr_timespec, Severity, std::string,
+                             RefCountedPtr<BaseNode>)>) const
+      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
 
   const size_t max_event_memory_;
   const gpr_timespec time_created_;

src/core/channelz/channelz.cc

@@ -25,6 +25,10 @@
 #include <algorithm>
 #include <atomic>
 #include <cstdint>
+#include <initializer_list>
+#include <limits>
+#include <string>
+#include <tuple>
 
 #include "absl/log/check.h"
 #include "absl/status/statusor.h"
@@ -39,12 +43,123 @@
 #include "src/core/lib/transport/connectivity_state.h"
 #include "src/core/util/json/json_writer.h"
 #include "src/core/util/string.h"
+#include "src/core/util/time.h"
 #include "src/core/util/uri.h"
 #include "src/core/util/useful.h"
 
 namespace grpc_core {
 namespace channelz {
 
+//
+// DataSink
+//
+
+namespace {
+class ChildObjectCollector {
+ public:
+  void Add(RefCountedPtr<BaseNode> node) {
+    child_objects_[node->type()].insert(node->uuid());
+  }
+
+  void Add(std::vector<RefCountedPtr<BaseNode>> nodes) {
+    for (auto& node : nodes) Add(std::move(node));
+  }
+
+  // Calls AddAdditionalInfo to export the collected child objects.
+  void Finalize(DataSink& sink) {
+    if (child_objects_.empty()) return;
+    Json::Object subobjects;
+    for (const auto& [type, child_objects] : child_objects_) {
+      std::string key;
+      switch (type) {
+        case BaseNode::EntityType::kTopLevelChannel:
+        case BaseNode::EntityType::kSubchannel:
+        case BaseNode::EntityType::kListenSocket:
+        case BaseNode::EntityType::kServer:
+        case BaseNode::EntityType::kInternalChannel: {
+          LOG(ERROR)
+              << "Nodes of type " << BaseNode::EntityTypeString(type)
+              << " not supported for child object collection in DataSink";
+          continue;
+        }
+        case BaseNode::EntityType::kSocket:
+          key = "subSockets";
+          break;
+        case BaseNode::EntityType::kCall:
+          key = "calls";
+          break;
+      }
+      Json::Array uuids;
+      uuids.reserve(child_objects.size());
+      for (int64_t uuid : child_objects) {
+        uuids.push_back(Json::FromNumber(uuid));
+      }
+      subobjects[key] = Json::FromArray(std::move(uuids));
+    }
+    sink.AddAdditionalInfo("childObjects", std::move(subobjects));
+  }
+
+ private:
+  std::map<BaseNode::EntityType, std::set<int64_t>> child_objects_;
+};
+
+class JsonDataSink final : public DataSink {
+ public:
+  explicit JsonDataSink(Json::Object& output) : output_(output) {
+    CHECK(output_.find("additionalInfo") == output_.end());
+  }
+  ~JsonDataSink() {
+    collector_.Finalize(*this);
+    if (additional_info_ != nullptr) {
+      output_["additionalInfo"] =
+          Json::FromObject(std::move(*additional_info_));
+    }
+  }
+
+  void AddAdditionalInfo(absl::string_view name,
+                         Json::Object additional_info) override {
+    if (additional_info_ == nullptr) {
+      additional_info_ = std::make_unique<Json::Object>();
+    }
+    additional_info_->emplace(name,
+                              Json::FromObject(std::move(additional_info)));
+  }
+
+  void AddChildObjects(
+      std::vector<RefCountedPtr<BaseNode>> child_objects) override {
+    collector_.Add(std::move(child_objects));
+  }
+
+ private:
+  Json::Object& output_;
+  std::unique_ptr<Json::Object> additional_info_;
+  ChildObjectCollector collector_;
+};
+
+class ExplicitJsonDataSink final : public DataSink {
+ public:
+  void AddAdditionalInfo(absl::string_view name,
+                         Json::Object additional_info) override {
+    additional_info_.emplace(name,
+                             Json::FromObject(std::move(additional_info)));
+  }
+
+  void AddChildObjects(
+      std::vector<RefCountedPtr<BaseNode>> child_objects) override {
+    collector_.Add(std::move(child_objects));
+  }
+
+  Json::Object Finalize() {
+    collector_.Finalize(*this);
+    return std::move(additional_info_);
+  }
+
+ private:
+  Json::Object additional_info_;
+  ChildObjectCollector collector_;
+};
+}  // namespace
+
 //
 // BaseNode
 //
@@ -55,13 +170,95 @@ BaseNode::BaseNode(EntityType type, std::string name)
   ChannelzRegistry::Register(this);
 }
 
-BaseNode::~BaseNode() { ChannelzRegistry::Unregister(uuid_); }
+void BaseNode::Orphaned() { ChannelzRegistry::Unregister(this); }
+
+intptr_t BaseNode::UuidSlow() { return ChannelzRegistry::NumberNode(this); }
 
 std::string BaseNode::RenderJsonString() {
   Json json = RenderJson();
   return JsonDump(json);
 }
 
+void BaseNode::PopulateJsonFromDataSources(Json::Object& json) {
+  JsonDataSink sink(json);
+  MutexLock lock(&data_sources_mu_);
+  for (DataSource* data_source : data_sources_) {
+    data_source->AddData(sink);
+  }
+}
+
+Json::Object BaseNode::AdditionalInfo() {
+  ExplicitJsonDataSink sink;
+  MutexLock lock(&data_sources_mu_);
+  for (DataSource* data_source : data_sources_) {
+    data_source->AddData(sink);
+  }
+  return sink.Finalize();
+}
+
+void BaseNode::RunZTrace(
+    absl::string_view name, Timestamp deadline,
+    std::map<std::string, std::string> args,
+    std::shared_ptr<grpc_event_engine::experimental::EventEngine> event_engine,
+    absl::AnyInvocable<void(Json)> callback) {
+  // Limit deadline to help contain potential resource exhaustion due to
+  // tracing.
+  deadline = std::min(deadline, Timestamp::Now() + Duration::Minutes(10));
+  auto fail = [&callback, event_engine](absl::Status status) {
+    event_engine->Run(
+        [callback = std::move(callback), status = std::move(status)]() mutable {
+          Json::Object object;
+          object["status"] = Json::FromString(status.ToString());
+          callback(Json::FromObject(std::move(object)));
+        });
+  };
+  std::unique_ptr<ZTrace> ztrace;
+  {
+    MutexLock lock(&data_sources_mu_);
+    for (auto* data_source : data_sources_) {
+      if (auto found_ztrace = data_source->GetZTrace(name);
+          found_ztrace != nullptr) {
+        if (ztrace == nullptr) {
+          ztrace = std::move(found_ztrace);
+        } else {
+          fail(absl::InternalError(
+              absl::StrCat("Ambiguous ztrace handler: ", name)));
+          return;
+        }
+      }
+    }
+  }
+  if (ztrace == nullptr) {
+    fail(absl::NotFoundError(absl::StrCat("ztrace not found: ", name)));
+    return;
+  }
+  ztrace->Run(deadline, std::move(args), event_engine, std::move(callback));
+}
+
+//
+// DataSource
+//
+
+DataSource::DataSource(RefCountedPtr<BaseNode> node) : node_(std::move(node)) {
+  if (node_ == nullptr) return;
+  MutexLock lock(&node_->data_sources_mu_);
+  node_->data_sources_.push_back(this);
+}
+
+DataSource::~DataSource() {
+  DCHECK(node_ == nullptr) << "DataSource must be ResetDataSource()'d in the "
+                              "most derived class before destruction";
+}
+
+void DataSource::ResetDataSource() {
+  RefCountedPtr<BaseNode> node = std::move(node_);
+  if (node == nullptr) return;
+  MutexLock lock(&node->data_sources_mu_);
+  node->data_sources_.erase(
+      std::remove(node->data_sources_.begin(), node->data_sources_.end(), this),
+      node->data_sources_.end());
+}
+
 //
 // CallCountingHelper
 //
@@ -80,24 +277,21 @@ void CallCountingHelper::RecordCallSucceeded() {
   calls_succeeded_.fetch_add(1, std::memory_order_relaxed);
 }
 
-void CallCountingHelper::PopulateCallCounts(Json::Object* json) {
-  auto calls_started = calls_started_.load(std::memory_order_relaxed);
-  auto calls_succeeded = calls_succeeded_.load(std::memory_order_relaxed);
-  auto calls_failed = calls_failed_.load(std::memory_order_relaxed);
-  auto last_call_started_cycle =
-      last_call_started_cycle_.load(std::memory_order_relaxed);
+//
+// CallCounts
+//
+
+void CallCounts::PopulateJson(Json::Object& json) const {
   if (calls_started != 0) {
-    (*json)["callsStarted"] = Json::FromString(absl::StrCat(calls_started));
-    gpr_timespec ts = gpr_convert_clock_type(
-        gpr_cycle_counter_to_time(last_call_started_cycle), GPR_CLOCK_REALTIME);
-    (*json)["lastCallStartedTimestamp"] =
-        Json::FromString(gpr_format_timespec(ts));
+    json["callsStarted"] = Json::FromString(absl::StrCat(calls_started));
+    json["lastCallStartedTimestamp"] =
+        Json::FromString(last_call_started_timestamp());
   }
   if (calls_succeeded != 0) {
-    (*json)["callsSucceeded"] = Json::FromString(absl::StrCat(calls_succeeded));
+    json["callsSucceeded"] = Json::FromString(absl::StrCat(calls_succeeded));
   }
   if (calls_failed != 0) {
-    (*json)["callsFailed"] = Json::FromString(absl::StrCat(calls_failed));
+    json["callsFailed"] = Json::FromString(absl::StrCat(calls_failed));
   }
 }
 
@@ -121,33 +315,20 @@ void PerCpuCallCountingHelper::RecordCallSucceeded() {
                                                      std::memory_order_relaxed);
 }
 
-void PerCpuCallCountingHelper::PopulateCallCounts(Json::Object* json) {
-  int64_t calls_started = 0;
-  int64_t calls_succeeded = 0;
-  int64_t calls_failed = 0;
-  gpr_cycle_counter last_call_started_cycle = 0;
+CallCounts PerCpuCallCountingHelper::GetCallCounts() const {
+  CallCounts call_counts;
   for (const auto& cpu : per_cpu_data_) {
-    calls_started += cpu.calls_started.load(std::memory_order_relaxed);
-    calls_succeeded += cpu.calls_succeeded.load(std::memory_order_relaxed);
-    calls_failed += cpu.calls_failed.load(std::memory_order_relaxed);
-    last_call_started_cycle =
-        std::max(last_call_started_cycle,
+    call_counts.calls_started +=
+        cpu.calls_started.load(std::memory_order_relaxed);
+    call_counts.calls_succeeded +=
+        cpu.calls_succeeded.load(std::memory_order_relaxed);
+    call_counts.calls_failed +=
+        cpu.calls_failed.load(std::memory_order_relaxed);
+    call_counts.last_call_started_cycle =
+        std::max(call_counts.last_call_started_cycle,
                  cpu.last_call_started_cycle.load(std::memory_order_relaxed));
   }
-
-  if (calls_started != 0) {
-    (*json)["callsStarted"] = Json::FromString(absl::StrCat(calls_started));
-    gpr_timespec ts = gpr_convert_clock_type(
-        gpr_cycle_counter_to_time(last_call_started_cycle), GPR_CLOCK_REALTIME);
-    (*json)["lastCallStartedTimestamp"] =
-        Json::FromString(gpr_format_timespec(ts));
-  }
-  if (calls_succeeded != 0) {
-    (*json)["callsSucceeded"] = Json::FromString(absl::StrCat(calls_succeeded));
-  }
-  if (calls_failed != 0) {
-    (*json)["callsFailed"] = Json::FromString(absl::StrCat(calls_failed));
-  }
+  return call_counts;
 }
 
 //
@@ -179,18 +360,48 @@ const char* ChannelNode::GetChannelConnectivityStateChangeString(
   GPR_UNREACHABLE_CODE(return "UNKNOWN");
 }
 
-Json ChannelNode::RenderJson() {
-  Json::Object data = {
-      {"target", Json::FromString(target_)},
-  };
+namespace {
+
+std::set<intptr_t> ChildIdSet(const BaseNode* parent,
+                              BaseNode::EntityType type) {
+  std::set<intptr_t> ids;
+  auto [children, _] = ChannelzRegistry::GetChildrenOfType(
+      0, parent, type, std::numeric_limits<size_t>::max());
+  for (const auto& node : children) {
+    ids.insert(node->uuid());
+  }
+  return ids;
+}
+
+}  // namespace
+
+std::set<intptr_t> ChannelNode::child_channels() const {
+  return ChildIdSet(this, BaseNode::EntityType::kInternalChannel);
+}
+
+std::set<intptr_t> ChannelNode::child_subchannels() const {
+  return ChildIdSet(this, BaseNode::EntityType::kSubchannel);
+}
+
+std::optional<std::string> ChannelNode::connectivity_state() {
   // Connectivity state.
   // If low-order bit is on, then the field is set.
   int state_field = connectivity_state_.load(std::memory_order_relaxed);
   if ((state_field & 1) != 0) {
     grpc_connectivity_state state =
         static_cast<grpc_connectivity_state>(state_field >> 1);
+    return ConnectivityStateName(state);
+  }
+  return std::nullopt;
+}
+
+Json ChannelNode::RenderJson() {
+  Json::Object data = {
+      {"target", Json::FromString(target_)},
+  };
+  if (auto cs = connectivity_state(); cs.has_value()) {
     data["state"] = Json::FromObject({
-        {"state", Json::FromString(ConnectivityStateName(state))},
+        {"state", Json::FromString(cs.value())},
     });
   }
   // Fill in the channel trace if applicable.
@@ -199,7 +410,7 @@ Json ChannelNode::RenderJson() {
     data["trace"] = std::move(trace_json);
   }
   // Ask CallCountingHelper to populate call count data.
-  call_counter_.PopulateCallCounts(&data);
+  call_counter_.GetCallCounts().PopulateJson(data);
   // Construct outer object.
   Json::Object json = {
       {"ref", Json::FromObject({
@@ -210,23 +421,25 @@ Json ChannelNode::RenderJson() {
   // Template method. Child classes may override this to add their specific
   // functionality.
   PopulateChildRefs(&json);
+  PopulateJsonFromDataSources(json);
   return Json::FromObject(std::move(json));
 }
 
 void ChannelNode::PopulateChildRefs(Json::Object* json) {
-  MutexLock lock(&child_mu_);
-  if (!child_subchannels_.empty()) {
+  auto child_subchannels = this->child_subchannels();
+  auto child_channels = this->child_channels();
+  if (!child_subchannels.empty()) {
     Json::Array array;
-    for (intptr_t subchannel_uuid : child_subchannels_) {
+    for (intptr_t subchannel_uuid : child_subchannels) {
       array.emplace_back(Json::FromObject({
           {"subchannelId", Json::FromString(absl::StrCat(subchannel_uuid))},
       }));
     }
     (*json)["subchannelRef"] = Json::FromArray(std::move(array));
   }
-  if (!child_channels_.empty()) {
+  if (!child_channels.empty()) {
     Json::Array array;
-    for (intptr_t channel_uuid : child_channels_) {
+    for (intptr_t channel_uuid : child_channels) {
       array.emplace_back(Json::FromObject({
           {"channelId", Json::FromString(absl::StrCat(channel_uuid))},
       }));
@@ -241,26 +454,6 @@ void ChannelNode::SetConnectivityState(grpc_connectivity_state state) {
   connectivity_state_.store(state_field, std::memory_order_relaxed);
 }
 
-void ChannelNode::AddChildChannel(intptr_t child_uuid) {
-  MutexLock lock(&child_mu_);
-  child_channels_.insert(child_uuid);
-}
-
-void ChannelNode::RemoveChildChannel(intptr_t child_uuid) {
-  MutexLock lock(&child_mu_);
-  child_channels_.erase(child_uuid);
-}
-
-void ChannelNode::AddChildSubchannel(intptr_t child_uuid) {
-  MutexLock lock(&child_mu_);
-  child_subchannels_.insert(child_uuid);
-}
-
-void ChannelNode::RemoveChildSubchannel(intptr_t child_uuid) {
-  MutexLock lock(&child_mu_);
-  child_subchannels_.erase(child_uuid);
-}
-
 //
 // SubchannelNode
 //
@@ -282,13 +475,17 @@ void SubchannelNode::SetChildSocket(RefCountedPtr<SocketNode> socket) {
   child_socket_ = std::move(socket);
 }
 
-Json SubchannelNode::RenderJson() {
-  // Create and fill the data child.
+std::string SubchannelNode::connectivity_state() const {
   grpc_connectivity_state state =
       connectivity_state_.load(std::memory_order_relaxed);
+  return ConnectivityStateName(state);
+}
+
+Json SubchannelNode::RenderJson() {
+  // Create and fill the data child.
   Json::Object data = {
       {"state", Json::FromObject({
-                    {"state", Json::FromString(ConnectivityStateName(state))},
+                    {"state", Json::FromString(connectivity_state())},
                 })},
       {"target", Json::FromString(target_)},
   };
@@ -298,7 +495,7 @@ Json SubchannelNode::RenderJson() {
     data["trace"] = std::move(trace_json);
   }
   // Ask CallCountingHelper to populate call count data.
-  call_counter_.PopulateCallCounts(&data);
+  call_counter_.GetCallCounts().PopulateJson(data);
   // Construct top-level object.
   Json::Object object{
       {"ref", Json::FromObject({
@@ -320,7 +517,8 @@ Json SubchannelNode::RenderJson() {
         }),
     });
   }
-  return Json::FromObject(object);
+  PopulateJsonFromDataSources(object);
+  return Json::FromObject(std::move(object));
 }
 
 //
@@ -332,51 +530,25 @@ ServerNode::ServerNode(size_t channel_tracer_max_nodes)
 
 ServerNode::~ServerNode() {}
 
-void ServerNode::AddChildSocket(RefCountedPtr<SocketNode> node) {
-  MutexLock lock(&child_mu_);
-  child_sockets_.insert(std::pair(node->uuid(), std::move(node)));
-}
-
-void ServerNode::RemoveChildSocket(intptr_t child_uuid) {
-  MutexLock lock(&child_mu_);
-  child_sockets_.erase(child_uuid);
-}
-
-void ServerNode::AddChildListenSocket(RefCountedPtr<ListenSocketNode> node) {
-  MutexLock lock(&child_mu_);
-  child_listen_sockets_.insert(std::pair(node->uuid(), std::move(node)));
-}
-
-void ServerNode::RemoveChildListenSocket(intptr_t child_uuid) {
-  MutexLock lock(&child_mu_);
-  child_listen_sockets_.erase(child_uuid);
-}
-
 std::string ServerNode::RenderServerSockets(intptr_t start_socket_id,
                                             intptr_t max_results) {
   CHECK_GE(start_socket_id, 0);
   CHECK_GE(max_results, 0);
   // If user does not set max_results, we choose 500.
-  size_t pagination_limit = max_results == 0 ? 500 : max_results;
+  if (max_results == 0) max_results = 500;
   Json::Object object;
-  {
-    MutexLock lock(&child_mu_);
-    size_t sockets_rendered = 0;
-    // Create list of socket refs.
-    Json::Array array;
-    auto it = child_sockets_.lower_bound(start_socket_id);
-    for (; it != child_sockets_.end() && sockets_rendered < pagination_limit;
-         ++it, ++sockets_rendered) {
-      array.emplace_back(Json::FromObject({
-          {"socketId", Json::FromString(absl::StrCat(it->first))},
-          {"name", Json::FromString(it->second->name())},
-      }));
-    }
-    object["socketRef"] = Json::FromArray(std::move(array));
-    if (it == child_sockets_.end()) {
-      object["end"] = Json::FromBool(true);
-    }
+  auto [children, end] = ChannelzRegistry::GetChildrenOfType(
+      start_socket_id, this, BaseNode::EntityType::kSocket, max_results);
+  // Create list of socket refs.
+  Json::Array array;
+  for (const auto& child : children) {
+    array.emplace_back(Json::FromObject({
+        {"socketId", Json::FromString(absl::StrCat(child->uuid()))},
+        {"name", Json::FromString(child->name())},
+    }));
   }
+  object["socketRef"] = Json::FromArray(std::move(array));
+  if (end) object["end"] = Json::FromBool(true);
   return JsonDump(Json::FromObject(std::move(object)));
 }
 
@@ -388,7 +560,7 @@ Json ServerNode::RenderJson() {
     data["trace"] = std::move(trace_json);
   }
   // Ask CallCountingHelper to populate call count data.
-  call_counter_.PopulateCallCounts(&data);
+  call_counter_.GetCallCounts().PopulateJson(data);
   // Construct top-level object.
   Json::Object object = {
       {"ref", Json::FromObject({
@@ -397,22 +569,47 @@ Json ServerNode::RenderJson() {
       {"data", Json::FromObject(std::move(data))},
   };
   // Render listen sockets.
-  {
-    MutexLock lock(&child_mu_);
-    if (!child_listen_sockets_.empty()) {
-      Json::Array array;
-      for (const auto& it : child_listen_sockets_) {
-        array.emplace_back(Json::FromObject({
-            {"socketId", Json::FromString(absl::StrCat(it.first))},
-            {"name", Json::FromString(it.second->name())},
-        }));
-      }
-      object["listenSocket"] = Json::FromArray(std::move(array));
+  auto [children, _] = ChannelzRegistry::GetChildrenOfType(
+      0, this, BaseNode::EntityType::kListenSocket,
+      std::numeric_limits<size_t>::max());
+  if (!children.empty()) {
+    Json::Array array;
+    for (const auto& child : children) {
+      array.emplace_back(Json::FromObject({
+          {"socketId", Json::FromString(absl::StrCat(child->uuid()))},
+          {"name", Json::FromString(child->name())},
+      }));
     }
+    object["listenSocket"] = Json::FromArray(std::move(array));
   }
+  PopulateJsonFromDataSources(object);
   return Json::FromObject(std::move(object));
 }
 
+std::map<intptr_t, RefCountedPtr<ListenSocketNode>>
+ServerNode::child_listen_sockets() const {
+  std::map<intptr_t, RefCountedPtr<ListenSocketNode>> result;
+  auto [children, _] = ChannelzRegistry::GetChildrenOfType(
+      0, this, BaseNode::EntityType::kListenSocket,
+      std::numeric_limits<size_t>::max());
+  for (const auto& child : children) {
+    result[child->uuid()] = child->RefAsSubclass<ListenSocketNode>();
+  }
+  return result;
+}
+
+std::map<intptr_t, RefCountedPtr<SocketNode>> ServerNode::child_sockets()
+    const {
+  std::map<intptr_t, RefCountedPtr<SocketNode>> result;
+  auto [children, _] = ChannelzRegistry::GetChildrenOfType(
+      0, this, BaseNode::EntityType::kSocket,
+      std::numeric_limits<size_t>::max());
+  for (const auto& child : children) {
+    result[child->uuid()] = child->RefAsSubclass<SocketNode>();
+  }
+  return result;
+}
+
 //
 // SocketNode::Security::Tls
 //
@@ -644,6 +841,7 @@ Json SocketNode::RenderJson() {
   }
   PopulateSocketAddressJson(&object, "remote", remote_.c_str());
   PopulateSocketAddressJson(&object, "local", local_.c_str());
+  PopulateJsonFromDataSources(object);
   return Json::FromObject(std::move(object));
 }
 
@@ -652,7 +850,7 @@ Json SocketNode::RenderJson() {
 //
 
 ListenSocketNode::ListenSocketNode(std::string local_addr, std::string name)
-    : BaseNode(EntityType::kSocket, std::move(name)),
+    : BaseNode(EntityType::kListenSocket, std::move(name)),
       local_addr_(std::move(local_addr)) {}
 
 Json ListenSocketNode::RenderJson() {
@@ -663,6 +861,21 @@ Json ListenSocketNode::RenderJson() {
               })},
   };
   PopulateSocketAddressJson(&object, "local", local_addr_.c_str());
+  PopulateJsonFromDataSources(object);
+  return Json::FromObject(std::move(object));
+}
+
+//
+// CallNode
+//
+
+Json CallNode::RenderJson() {
+  Json::Object object = {
+      {"ref", Json::FromObject({
+                  {"callId", Json::FromString(absl::StrCat(uuid()))},
+              })},
+  };
+  PopulateJsonFromDataSources(object);
   return Json::FromObject(std::move(object));
 }
 

src/core/channelz/channelz.h

@@ -27,6 +27,7 @@
 
 #include <atomic>
 #include <cstdint>
+#include <initializer_list>
 #include <map>
 #include <optional>
 #include <set>
@@ -34,18 +35,29 @@
 #include <utility>
 
 #include "absl/base/thread_annotations.h"
+#include "absl/container/flat_hash_set.h"
+#include "absl/container/inlined_vector.h"
 #include "absl/strings/string_view.h"
 #include "src/core/channelz/channel_trace.h"
+#include "src/core/lib/channel/channel_args.h"
+#include "src/core/util/dual_ref_counted.h"
 #include "src/core/util/json/json.h"
 #include "src/core/util/per_cpu.h"
 #include "src/core/util/ref_counted.h"
 #include "src/core/util/ref_counted_ptr.h"
+#include "src/core/util/string.h"
 #include "src/core/util/sync.h"
+#include "src/core/util/time.h"
 #include "src/core/util/time_precise.h"
 #include "src/core/util/useful.h"
 
 // Channel arg key for channelz node.
-#define GRPC_ARG_CHANNELZ_CHANNEL_NODE "grpc.internal.channelz_channel_node"
+#define GRPC_ARG_CHANNELZ_CHANNEL_NODE \
+  "grpc.internal.no_subchannel.channelz_channel_node"
+
+// Channel arg key for the containing base node
+#define GRPC_ARG_CHANNELZ_CONTAINING_BASE_NODE \
+  "grpc.internal.no_subchannel.channelz_containing_base_node"
 
 // Channel arg key for indicating an internal channel.
 #define GRPC_ARG_CHANNELZ_IS_INTERNAL_CHANNEL \
@@ -67,6 +79,8 @@ namespace channelz {
 
 class SocketNode;
 class ListenSocketNode;
+class DataSource;
+class ZTrace;
 
 namespace testing {
 class CallCountingHelperPeer;
@@ -74,7 +88,7 @@ class SubchannelNodePeer;
 }  // namespace testing
 
 // base class for all channelz entities
-class BaseNode : public RefCounted<BaseNode> {
+class BaseNode : public DualRefCounted<BaseNode> {
  public:
   // There are only four high level channelz entities. However, to support
   // GetTopChannelsRequest, we split the Channel entity into two different
@@ -84,14 +98,58 @@ class BaseNode : public RefCounted<BaseNode> {
     kInternalChannel,
     kSubchannel,
     kServer,
+    kListenSocket,
     kSocket,
+    kCall,
   };
 
+  static absl::string_view EntityTypeString(EntityType type) {
+    switch (type) {
+      case EntityType::kTopLevelChannel:
+        return "top_level_channel";
+      case EntityType::kInternalChannel:
+        return "internal_channel";
+      case EntityType::kSubchannel:
+        return "subchannel";
+      case EntityType::kServer:
+        return "server";
+      case EntityType::kListenSocket:
+        return "listen_socket";
+      case EntityType::kSocket:
+        return "socket";
+      case EntityType::kCall:
+        return "call";
+    }
+    return "unknown";
+  }
+
  protected:
   BaseNode(EntityType type, std::string name);
 
  public:
-  ~BaseNode() override;
+  void Orphaned() override;
+
+  bool HasParent(const BaseNode* parent) const {
+    MutexLock lock(&parent_mu_);
+    return parents_.find(parent) != parents_.end();
+  }
+
+  void AddParent(BaseNode* parent) {
+    MutexLock lock(&parent_mu_);
+    parents_.insert(parent->WeakRef());
+  }
+
+  void RemoveParent(BaseNode* parent) {
+    MutexLock lock(&parent_mu_);
+    parents_.erase(parent);
+  }
+
+  static absl::string_view ChannelArgName() {
+    return GRPC_ARG_CHANNELZ_CONTAINING_BASE_NODE;
+  }
+  static int ChannelArgsCompare(const BaseNode* a, const BaseNode* b) {
+    return QsortCompare(a, b);
+  }
 
   // All children must implement this function.
   virtual Json RenderJson() = 0;
@@ -101,15 +159,107 @@ class BaseNode : public RefCounted<BaseNode> {
   std::string RenderJsonString();
 
   EntityType type() const { return type_; }
-  intptr_t uuid() const { return uuid_; }
+  intptr_t uuid() {
+    const intptr_t id = uuid_.load(std::memory_order_relaxed);
+    if (id > 0) return id;
+    return UuidSlow();
+  }
   const std::string& name() const { return name_; }
 
+  void RunZTrace(absl::string_view name, Timestamp deadline,
+                 std::map<std::string, std::string> args,
+                 std::shared_ptr<grpc_event_engine::experimental::EventEngine>
+                     event_engine,
+                 absl::AnyInvocable<void(Json output)> callback);
+  Json::Object AdditionalInfo();
+
+ protected:
+  void PopulateJsonFromDataSources(Json::Object& json);
+
  private:
   // to allow the ChannelzRegistry to set uuid_ under its lock.
   friend class ChannelzRegistry;
+  // allow data source to register/unregister itself
+  friend class DataSource;
+  using ParentSet = absl::flat_hash_set<WeakRefCountedPtr<BaseNode>,
+                                        WeakRefCountedPtrHash<BaseNode>,
+                                        WeakRefCountedPtrEq<BaseNode>>;
+
+  intptr_t UuidSlow();
+
   const EntityType type_;
-  intptr_t uuid_;
+  uint64_t orphaned_index_ = 0;  // updated by registry
+  std::atomic<intptr_t> uuid_;
   std::string name_;
+  Mutex data_sources_mu_;
+  absl::InlinedVector<DataSource*, 3> data_sources_
+      ABSL_GUARDED_BY(data_sources_mu_);
+  BaseNode* prev_;  // updated by registry
+  BaseNode* next_;  // updated by registry
+  mutable Mutex parent_mu_;
+  ParentSet parents_ ABSL_GUARDED_BY(parent_mu_);
+};
+
+class ZTrace {
+ public:
+  virtual ~ZTrace() = default;
+  virtual void Run(Timestamp deadline, std::map<std::string, std::string> args,
+                   std::shared_ptr<grpc_event_engine::experimental::EventEngine>
+                       event_engine,
+                   absl::AnyInvocable<void(Json)>) = 0;
+};
+
+class DataSink {
+ public:
+  virtual void AddAdditionalInfo(absl::string_view name,
+                                 Json::Object additional_info) = 0;
+  virtual void AddChildObjects(
+      std::vector<RefCountedPtr<BaseNode>> children) = 0;
+
+ protected:
+  ~DataSink() = default;
+};
+
+class DataSource {
+ public:
+  explicit DataSource(RefCountedPtr<BaseNode> node);
+
+  // Add any relevant json fragments to the output.
+  // This method must not cause the DataSource to be deleted, or else there will
+  // be a deadlock.
+  virtual void AddData(DataSink&) {}
+
+  // If this data source exports some ztrace, return it here.
+  virtual std::unique_ptr<ZTrace> GetZTrace(absl::string_view /*name*/) {
+    return nullptr;
+  }
+
+ protected:
+  ~DataSource();
+  RefCountedPtr<BaseNode> channelz_node() { return node_; }
+
+  // This method must be called in the most derived class's destructor.
+  // It removes this data source from the node's list of data sources.
+  // If it is not called, then the AddData() function pointer may be invalid
+  // when the node is queried.
+  void ResetDataSource();
+
+ private:
+  RefCountedPtr<BaseNode> node_;
+};
+
+struct CallCounts {
+  int64_t calls_started = 0;
+  int64_t calls_succeeded = 0;
+  int64_t calls_failed = 0;
+  gpr_cycle_counter last_call_started_cycle = 0;
+
+  std::string last_call_started_timestamp() const {
+    return gpr_format_timespec(
+        gpr_cycle_counter_to_time(last_call_started_cycle));
+  }
+
+  void PopulateJson(Json::Object& json) const;
 };
 
 // This class is a helper class for channelz entities that deal with Channels,
@@ -124,8 +274,14 @@ class CallCountingHelper final {
   void RecordCallFailed();
   void RecordCallSucceeded();
 
-  // Common rendering of the call count data and last_call_started_timestamp.
-  void PopulateCallCounts(Json::Object* json);
+  CallCounts GetCallCounts() const {
+    return {
+        calls_started_.load(std::memory_order_relaxed),
+        calls_succeeded_.load(std::memory_order_relaxed),
+        calls_failed_.load(std::memory_order_relaxed),
+        last_call_started_cycle_.load(std::memory_order_relaxed),
+    };
+  }
 
  private:
   // testing peer friend.
@@ -143,8 +299,7 @@ class PerCpuCallCountingHelper final {
   void RecordCallFailed();
   void RecordCallSucceeded();
 
-  // Common rendering of the call count data and last_call_started_timestamp.
-  void PopulateCallCounts(Json::Object* json);
+  CallCounts GetCallCounts() const;
 
  private:
   // testing peer friend.
@@ -167,6 +322,11 @@ class ChannelNode final : public BaseNode {
   ChannelNode(std::string target, size_t channel_tracer_max_nodes,
               bool is_internal_channel);
 
+  void Orphaned() override {
+    channel_args_ = ChannelArgs();
+    BaseNode::Orphaned();
+  }
+
   static absl::string_view ChannelArgName() {
     return GRPC_ARG_CHANNELZ_CHANNEL_NODE;
   }
@@ -190,21 +350,22 @@ class ChannelNode final : public BaseNode {
     trace_.AddTraceEventWithReference(severity, data,
                                       std::move(referenced_channel));
   }
+  void SetChannelArgs(const ChannelArgs& channel_args) {
+    channel_args_ = channel_args;
+  }
   void RecordCallStarted() { call_counter_.RecordCallStarted(); }
   void RecordCallFailed() { call_counter_.RecordCallFailed(); }
   void RecordCallSucceeded() { call_counter_.RecordCallSucceeded(); }
 
   void SetConnectivityState(grpc_connectivity_state state);
 
-  // TODO(roth): take in a RefCountedPtr to the child channel so we can retrieve
-  // the human-readable name.
-  void AddChildChannel(intptr_t child_uuid);
-  void RemoveChildChannel(intptr_t child_uuid);
-
-  // TODO(roth): take in a RefCountedPtr to the child subchannel so we can
-  // retrieve the human-readable name.
-  void AddChildSubchannel(intptr_t child_uuid);
-  void RemoveChildSubchannel(intptr_t child_uuid);
+  const std::string& target() const { return target_; }
+  std::optional<std::string> connectivity_state();
+  CallCounts GetCallCounts() const { return call_counter_.GetCallCounts(); }
+  std::set<intptr_t> child_channels() const;
+  std::set<intptr_t> child_subchannels() const;
+  const ChannelTrace& trace() const { return trace_; }
+  const ChannelArgs& channel_args() const { return channel_args_; }
 
  private:
   void PopulateChildRefs(Json::Object* json);
@@ -212,14 +373,13 @@ class ChannelNode final : public BaseNode {
   std::string target_;
   CallCountingHelper call_counter_;
   ChannelTrace trace_;
+  // TODO(ctiller): keeping channel args here can create odd circular references
+  // that are hard to reason about. Consider moving this to a DataSource.
+  ChannelArgs channel_args_;
 
   // Least significant bit indicates whether the value is set.  Remaining
   // bits are a grpc_connectivity_state value.
   std::atomic<int> connectivity_state_{0};
-
-  Mutex child_mu_;  // Guards sets below.
-  std::set<intptr_t> child_channels_;
-  std::set<intptr_t> child_subchannels_;
 };
 
 // Handles channelz bookkeeping for subchannels
@@ -228,6 +388,11 @@ class SubchannelNode final : public BaseNode {
   SubchannelNode(std::string target_address, size_t channel_tracer_max_nodes);
   ~SubchannelNode() override;
 
+  void Orphaned() override {
+    channel_args_ = ChannelArgs();
+    BaseNode::Orphaned();
+  }
+
   // Sets the subchannel's connectivity state without health checking.
   void UpdateConnectivityState(grpc_connectivity_state state);
 
@@ -242,6 +407,9 @@ class SubchannelNode final : public BaseNode {
   void AddTraceEvent(ChannelTrace::Severity severity, const grpc_slice& data) {
     trace_.AddTraceEvent(severity, data);
   }
+  void SetChannelArgs(const ChannelArgs& channel_args) {
+    channel_args_ = channel_args;
+  }
   void AddTraceEventWithReference(ChannelTrace::Severity severity,
                                   const grpc_slice& data,
                                   RefCountedPtr<BaseNode> referenced_channel) {
@@ -252,16 +420,29 @@ class SubchannelNode final : public BaseNode {
   void RecordCallFailed() { call_counter_.RecordCallFailed(); }
   void RecordCallSucceeded() { call_counter_.RecordCallSucceeded(); }
 
+  const std::string& target() const { return target_; }
+  std::string connectivity_state() const;
+  CallCounts GetCallCounts() const { return call_counter_.GetCallCounts(); }
+  RefCountedPtr<SocketNode> child_socket() const {
+    MutexLock lock(&socket_mu_);
+    return child_socket_;
+  }
+  const ChannelTrace& trace() const { return trace_; }
+  const ChannelArgs& channel_args() const { return channel_args_; }
+
  private:
   // Allows the channel trace test to access trace_.
   friend class testing::SubchannelNodePeer;
 
   std::atomic<grpc_connectivity_state> connectivity_state_{GRPC_CHANNEL_IDLE};
-  Mutex socket_mu_;
+  mutable Mutex socket_mu_;
   RefCountedPtr<SocketNode> child_socket_ ABSL_GUARDED_BY(socket_mu_);
   std::string target_;
   CallCountingHelper call_counter_;
   ChannelTrace trace_;
+  // TODO(ctiller): keeping channel args here can create odd circular references
+  // that are hard to reason about. Consider moving this to a DataSource.
+  ChannelArgs channel_args_;
 };
 
 // Handles channelz bookkeeping for servers
@@ -271,19 +452,16 @@ class ServerNode final : public BaseNode {
 
   ~ServerNode() override;
 
+  void Orphaned() override {
+    channel_args_ = ChannelArgs();
+    BaseNode::Orphaned();
+  }
+
   Json RenderJson() override;
 
   std::string RenderServerSockets(intptr_t start_socket_id,
                                   intptr_t max_results);
 
-  void AddChildSocket(RefCountedPtr<SocketNode> node);
-
-  void RemoveChildSocket(intptr_t child_uuid);
-
-  void AddChildListenSocket(RefCountedPtr<ListenSocketNode> node);
-
-  void RemoveChildListenSocket(intptr_t child_uuid);
-
   // proxy methods to composed classes.
   void AddTraceEvent(ChannelTrace::Severity severity, const grpc_slice& data) {
     trace_.AddTraceEvent(severity, data);
@@ -294,16 +472,28 @@ class ServerNode final : public BaseNode {
     trace_.AddTraceEventWithReference(severity, data,
                                       std::move(referenced_channel));
   }
+  void SetChannelArgs(const ChannelArgs& channel_args) {
+    channel_args_ = channel_args;
+  }
   void RecordCallStarted() { call_counter_.RecordCallStarted(); }
   void RecordCallFailed() { call_counter_.RecordCallFailed(); }
   void RecordCallSucceeded() { call_counter_.RecordCallSucceeded(); }
 
+  CallCounts GetCallCounts() const { return call_counter_.GetCallCounts(); }
+
+  std::map<intptr_t, RefCountedPtr<ListenSocketNode>> child_listen_sockets()
+      const;
+  std::map<intptr_t, RefCountedPtr<SocketNode>> child_sockets() const;
+
+  const ChannelTrace& trace() const { return trace_; }
+  const ChannelArgs& channel_args() const { return channel_args_; }
+
  private:
   PerCpuCallCountingHelper call_counter_;
   ChannelTrace trace_;
-  Mutex child_mu_;  // Guards child maps below.
-  std::map<intptr_t, RefCountedPtr<SocketNode>> child_sockets_;
-  std::map<intptr_t, RefCountedPtr<ListenSocketNode>> child_listen_sockets_;
+  // TODO(ctiller): keeping channel args here can create odd circular references
+  // that are hard to reason about. Consider moving this to a DataSource.
+  ChannelArgs channel_args_;
 };
 
 #define GRPC_ARG_CHANNELZ_SECURITY "grpc.internal.channelz_security"
@@ -368,7 +558,51 @@ class SocketNode final : public BaseNode {
 
   const std::string& remote() { return remote_; }
 
+  int64_t streams_started() const {
+    return streams_started_.load(std::memory_order_relaxed);
+  }
+  int64_t streams_succeeded() const {
+    return streams_succeeded_.load(std::memory_order_relaxed);
+  }
+  int64_t streams_failed() const {
+    return streams_failed_.load(std::memory_order_relaxed);
+  }
+  int64_t messages_sent() const {
+    return messages_sent_.load(std::memory_order_relaxed);
+  }
+  int64_t messages_received() const {
+    return messages_received_.load(std::memory_order_relaxed);
+  }
+  int64_t keepalives_sent() const {
+    return keepalives_sent_.load(std::memory_order_relaxed);
+  }
+  auto last_local_stream_created_timestamp() const {
+    return CycleCounterToTimestamp(
+        last_local_stream_created_cycle_.load(std::memory_order_relaxed));
+  }
+  auto last_remote_stream_created_timestamp() const {
+    return CycleCounterToTimestamp(
+        last_remote_stream_created_cycle_.load(std::memory_order_relaxed));
+  }
+  auto last_message_sent_timestamp() const {
+    return CycleCounterToTimestamp(
+        last_message_sent_cycle_.load(std::memory_order_relaxed));
+  }
+  auto last_message_received_timestamp() const {
+    return CycleCounterToTimestamp(
+        last_message_received_cycle_.load(std::memory_order_relaxed));
+  }
+  const std::string& local() const { return local_; }
+  const std::string& remote() const { return remote_; }
+
+  RefCountedPtr<Security> security() const { return security_; }
+
  private:
+  std::optional<std::string> CycleCounterToTimestamp(
+      gpr_cycle_counter cycle_counter) const {
+    return gpr_format_timespec(gpr_cycle_counter_to_time(cycle_counter));
+  }
+
   std::atomic<int64_t> streams_started_{0};
   std::atomic<int64_t> streams_succeeded_{0};
   std::atomic<int64_t> streams_failed_{0};
@@ -396,6 +630,14 @@ class ListenSocketNode final : public BaseNode {
   std::string local_addr_;
 };
 
+class CallNode final : public BaseNode {
+ public:
+  explicit CallNode(std::string name)
+      : BaseNode(EntityType::kCall, std::move(name)) {}
+
+  Json RenderJson() override;
+};
+
 }  // namespace channelz
 }  // namespace grpc_core
 

src/core/channelz/channelz_registry.cc

@@ -24,154 +24,356 @@
 #include <grpc/support/string_util.h>
 
 #include <algorithm>
+#include <atomic>
 #include <cstdint>
 #include <cstring>
+#include <memory>
+#include <optional>
+#include <string>
 #include <utility>
 #include <vector>
 
 #include "absl/log/check.h"
 #include "absl/log/log.h"
 #include "src/core/channelz/channelz.h"
+#include "src/core/config/config_vars.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/util/json/json.h"
+#include "src/core/util/json/json_reader.h"
 #include "src/core/util/json/json_writer.h"
+#include "src/core/util/shared_bit_gen.h"
 #include "src/core/util/sync.h"
 
 namespace grpc_core {
 namespace channelz {
+
 namespace {
+template <typename T>
+std::string RenderArray(std::tuple<T, bool> values_and_end,
+                        const std::string& key) {
+  auto& [values, end] = values_and_end;
+  Json::Object object;
+  if (!values.empty()) {
+    // Create list of channels.
+    Json::Array array;
+    for (size_t i = 0; i < values.size(); ++i) {
+      array.emplace_back(values[i]->RenderJson());
+    }
+    object[key] = Json::FromArray(std::move(array));
+  }
+  if (end) {
+    object["end"] = Json::FromBool(true);
+  }
+  return JsonDump(Json::FromObject(std::move(object)));
+}
 
-const int kPaginationLimit = 100;
+Json RemoveAdditionalInfo(const Json& json) {
+  switch (json.type()) {
+    case Json::Type::kArray: {
+      Json::Array out;
+      for (const auto& node : json.array()) {
+        out.emplace_back(RemoveAdditionalInfo(node));
+      }
+      return Json::FromArray(std::move(out));
+    } break;
+    case Json::Type::kObject: {
+      Json::Object out;
+      for (const auto& [key, value] : json.object()) {
+        if (key == "additionalInfo") continue;
+        out[key] = RemoveAdditionalInfo(value);
+      }
+      return Json::FromObject(std::move(out));
+    } break;
+    default:
+      return json;
+  }
+}
 
-}  // anonymous namespace
+// TODO(ctiller): Temporary hack to remove fields that are objectionable to the
+// protobuf parser (because we've not published them in protobuf yet).
+char* ApplyHacks(const std::string& json_str) {
+  return gpr_strdup(StripAdditionalInfoFromJson(json_str).c_str());
+}
+}  // namespace
+
+std::string StripAdditionalInfoFromJson(absl::string_view json_str) {
+  auto json = JsonParse(json_str);
+  if (!json.ok()) return gpr_strdup(std::string(json_str).c_str());
+  return JsonDump(RemoveAdditionalInfo(*json));
+}
 
 ChannelzRegistry* ChannelzRegistry::Default() {
   static ChannelzRegistry* singleton = new ChannelzRegistry();
   return singleton;
 }
 
-void ChannelzRegistry::InternalRegister(BaseNode* node) {
-  MutexLock lock(&mu_);
-  node->uuid_ = ++uuid_generator_;
-  node_map_[node->uuid_] = node;
-}
-
-void ChannelzRegistry::InternalUnregister(intptr_t uuid) {
-  CHECK_GE(uuid, 1);
-  MutexLock lock(&mu_);
-  CHECK(uuid <= uuid_generator_);
-  node_map_.erase(uuid);
-}
-
-RefCountedPtr<BaseNode> ChannelzRegistry::InternalGet(intptr_t uuid) {
-  MutexLock lock(&mu_);
-  if (uuid < 1 || uuid > uuid_generator_) {
-    return nullptr;
-  }
-  auto it = node_map_.find(uuid);
-  if (it == node_map_.end()) return nullptr;
-  // Found node.  Return only if its refcount is not zero (i.e., when we
-  // know that there is no other thread about to destroy it).
-  BaseNode* node = it->second;
-  return node->RefIfNonZero();
-}
-
-std::string ChannelzRegistry::InternalGetTopChannels(
-    intptr_t start_channel_id) {
-  std::vector<RefCountedPtr<BaseNode>> top_level_channels;
-  RefCountedPtr<BaseNode> node_after_pagination_limit;
-  {
-    MutexLock lock(&mu_);
-    for (auto it = node_map_.lower_bound(start_channel_id);
-         it != node_map_.end(); ++it) {
-      BaseNode* node = it->second;
-      RefCountedPtr<BaseNode> node_ref;
-      if (node->type() == BaseNode::EntityType::kTopLevelChannel &&
-          (node_ref = node->RefIfNonZero()) != nullptr) {
-        // Check if we are over pagination limit to determine if we need to set
-        // the "end" element. If we don't go through this block, we know that
-        // when the loop terminates, we have <= to kPaginationLimit.
-        // Note that because we have already increased this node's
-        // refcount, we need to decrease it, but we can't unref while
-        // holding the lock, because this may lead to a deadlock.
-        if (top_level_channels.size() == kPaginationLimit) {
-          node_after_pagination_limit = std::move(node_ref);
-          break;
-        }
-        top_level_channels.emplace_back(std::move(node_ref));
-      }
-    }
-  }
-  Json::Object object;
-  if (!top_level_channels.empty()) {
-    // Create list of channels.
-    Json::Array array;
-    for (size_t i = 0; i < top_level_channels.size(); ++i) {
-      array.emplace_back(top_level_channels[i]->RenderJson());
-    }
-    object["channel"] = Json::FromArray(std::move(array));
-  }
-  if (node_after_pagination_limit == nullptr) {
-    object["end"] = Json::FromBool(true);
-  }
-  return JsonDump(Json::FromObject(std::move(object)));
-}
-
-std::string ChannelzRegistry::InternalGetServers(intptr_t start_server_id) {
-  std::vector<RefCountedPtr<BaseNode>> servers;
-  RefCountedPtr<BaseNode> node_after_pagination_limit;
-  {
-    MutexLock lock(&mu_);
-    for (auto it = node_map_.lower_bound(start_server_id);
-         it != node_map_.end(); ++it) {
-      BaseNode* node = it->second;
-      RefCountedPtr<BaseNode> node_ref;
-      if (node->type() == BaseNode::EntityType::kServer &&
-          (node_ref = node->RefIfNonZero()) != nullptr) {
-        // Check if we are over pagination limit to determine if we need to set
-        // the "end" element. If we don't go through this block, we know that
-        // when the loop terminates, we have <= to kPaginationLimit.
-        // Note that because we have already increased this node's
-        // refcount, we need to decrease it, but we can't unref while
-        // holding the lock, because this may lead to a deadlock.
-        if (servers.size() == kPaginationLimit) {
-          node_after_pagination_limit = std::move(node_ref);
-          break;
-        }
-        servers.emplace_back(std::move(node_ref));
-      }
-    }
-  }
-  Json::Object object;
-  if (!servers.empty()) {
-    // Create list of servers.
-    Json::Array array;
-    for (size_t i = 0; i < servers.size(); ++i) {
-      array.emplace_back(servers[i]->RenderJson());
-    }
-    object["server"] = Json::FromArray(std::move(array));
-  }
-  if (node_after_pagination_limit == nullptr) {
-    object["end"] = Json::FromBool(true);
-  }
-  return JsonDump(Json::FromObject(std::move(object)));
+std::vector<WeakRefCountedPtr<BaseNode>>
+ChannelzRegistry::InternalGetAllEntities() {
+  return std::get<0>(QueryNodes(
+      0, [](const BaseNode*) { return true; },
+      std::numeric_limits<size_t>::max()));
 }
 
 void ChannelzRegistry::InternalLogAllEntities() {
-  std::vector<RefCountedPtr<BaseNode>> nodes;
-  {
-    MutexLock lock(&mu_);
-    for (auto& p : node_map_) {
-      RefCountedPtr<BaseNode> node = p.second->RefIfNonZero();
-      if (node != nullptr) {
-        nodes.emplace_back(std::move(node));
+  for (const auto& p : InternalGetAllEntities()) {
+    std::string json = p->RenderJsonString();
+    LOG(INFO) << json;
+  }
+}
+
+std::string ChannelzRegistry::GetTopChannelsJson(intptr_t start_channel_id) {
+  return RenderArray(GetTopChannels(start_channel_id), "channel");
+}
+
+std::string ChannelzRegistry::GetServersJson(intptr_t start_server_id) {
+  return RenderArray(GetServers(start_server_id), "server");
+}
+
+void ChannelzRegistry::InternalRegister(BaseNode* node) {
+  DCHECK_EQ(node->uuid_, -1);
+  const size_t node_shard_index = NodeShardIndex(node);
+  NodeShard& node_shard = node_shards_[node_shard_index];
+  MutexLock lock(&node_shard.mu);
+  node_shard.nursery.AddToHead(node);
+}
+
+void ChannelzRegistry::InternalUnregister(BaseNode* node) {
+  const size_t node_shard_index = NodeShardIndex(node);
+  NodeShard& node_shard = node_shards_[node_shard_index];
+  node_shard.mu.Lock();
+  CHECK_EQ(node->orphaned_index_, 0u);
+  intptr_t uuid = node->uuid_.load(std::memory_order_relaxed);
+  NodeList& remove_list = uuid == -1 ? node_shard.nursery : node_shard.numbered;
+  remove_list.Remove(node);
+  if (max_orphaned_per_shard_ == 0) {
+    // We are not tracking orphaned nodes... remove from the index
+    // if necessary, then exit out.
+    node_shard.mu.Unlock();
+    if (uuid != -1) {
+      MutexLock lock(&index_mu_);
+      index_.erase(uuid);
+    }
+    return;
+  }
+  NodeList& add_list =
+      uuid != -1 ? node_shard.orphaned_numbered : node_shard.orphaned;
+  // Ref counting: once a node becomes orphaned we add a single weak ref to it.
+  // We hold that ref until it gets garbage collected later.
+  node->WeakRef().release();
+  node->orphaned_index_ = node_shard.next_orphan_index;
+  CHECK_GT(node->orphaned_index_, 0u);
+  ++node_shard.next_orphan_index;
+  add_list.AddToHead(node);
+  if (node_shard.TotalOrphaned() <= max_orphaned_per_shard_) {
+    // Below recycling thresholds: just exit out
+    node_shard.mu.Unlock();
+    return;
+  }
+  CHECK_EQ(node_shard.TotalOrphaned(), max_orphaned_per_shard_ + 1);
+  NodeList* gc_list;
+  // choose the oldest node to evict, regardless of numbered or not
+  if (node_shard.orphaned.tail == nullptr) {
+    CHECK_NE(node_shard.orphaned_numbered.tail, nullptr);
+    gc_list = &node_shard.orphaned_numbered;
+  } else if (node_shard.orphaned_numbered.tail == nullptr) {
+    gc_list = &node_shard.orphaned;
+  } else if (node_shard.orphaned.tail->orphaned_index_ <
+             node_shard.orphaned_numbered.tail->orphaned_index_) {
+    gc_list = &node_shard.orphaned;
+  } else {
+    gc_list = &node_shard.orphaned_numbered;
+  }
+  auto* n = gc_list->tail;
+  CHECK_GT(n->orphaned_index_, 0u);
+  gc_list->Remove(n);
+  // Note: we capture the reference to n previously added here, and release
+  // it when this smart pointer is destroyed, outside of any locks.
+  WeakRefCountedPtr<BaseNode> gcd_node(n);
+  node_shard.mu.Unlock();
+  if (gc_list == &node_shard.orphaned_numbered) {
+    MutexLock lock(&index_mu_);
+    intptr_t uuid = n->uuid_.load(std::memory_order_relaxed);
+    index_.erase(uuid);
+  }
+}
+
+void ChannelzRegistry::LoadConfig() {
+  const auto max_orphaned = ConfigVars::Get().ChannelzMaxOrphanedNodes();
+  if (max_orphaned == 0) {
+    max_orphaned_per_shard_ = 0;
+  } else {
+    max_orphaned_per_shard_ = std::max<int>(max_orphaned / kNodeShards, 1);
+  }
+}
+
+std::tuple<std::vector<WeakRefCountedPtr<BaseNode>>, bool>
+ChannelzRegistry::QueryNodes(
+    intptr_t start_node, absl::FunctionRef<bool(const BaseNode*)> discriminator,
+    size_t max_results) {
+  // Mitigate drain hotspotting by randomizing the drain order each query.
+  std::vector<size_t> nursery_visitation_order;
+  for (size_t i = 0; i < kNodeShards; ++i) {
+    nursery_visitation_order.push_back(i);
+  }
+  absl::c_shuffle(nursery_visitation_order, SharedBitGen());
+  // In the iteration below, even once we have max_results nodes, we need
+  // to find the next node in order to know if we've hit the end.  If we get
+  // through the loop without returning, then we return end=true.  But if we
+  // find a node to add after we already have max_results nodes, then we
+  // return with end=false before exiting the loop.  However, in the latter
+  // case, we will have already increased the ref count of the next node,
+  // so we need to unref it, but we can't do that while holding the lock.
+  // So instead, we store it in node_after_end, which will be unreffed
+  // after releasing the lock.
+  WeakRefCountedPtr<BaseNode> node_after_end;
+  std::vector<WeakRefCountedPtr<BaseNode>> result;
+  MutexLock index_lock(&index_mu_);
+  for (auto it = index_.lower_bound(start_node); it != index_.end(); ++it) {
+    BaseNode* node = it->second;
+    if (!discriminator(node)) continue;
+    auto node_ref = node->WeakRefIfNonZero();
+    if (node_ref == nullptr) continue;
+    if (result.size() == max_results) {
+      node_after_end = std::move(node_ref);
+      return std::tuple(std::move(result), false);
+    }
+    result.emplace_back(std::move(node_ref));
+  }
+  for (auto nursery_index : nursery_visitation_order) {
+    NodeShard& node_shard = node_shards_[nursery_index];
+    MutexLock shard_lock(&node_shard.mu);
+    for (auto [nursery, numbered] :
+         {std::pair(&node_shard.nursery, &node_shard.numbered),
+          std::pair(&node_shard.orphaned, &node_shard.orphaned_numbered)}) {
+      if (nursery->head == nullptr) continue;
+      BaseNode* n = nursery->head;
+      while (n != nullptr) {
+        if (!discriminator(n)) {
+          n = n->next_;
+          continue;
+        }
+        auto node_ref = n->WeakRefIfNonZero();
+        if (node_ref == nullptr) {
+          n = n->next_;
+          continue;
+        }
+        BaseNode* next = n->next_;
+        nursery->Remove(n);
+        numbered->AddToHead(n);
+        n->uuid_ = uuid_generator_;
+        ++uuid_generator_;
+        index_.emplace(n->uuid_, n);
+        if (n->uuid_ >= start_node) {
+          if (result.size() == max_results) {
+            node_after_end = std::move(node_ref);
+            return std::tuple(std::move(result), false);
+          }
+          result.emplace_back(std::move(node_ref));
+        }
+        n = next;
       }
     }
   }
-  for (size_t i = 0; i < nodes.size(); ++i) {
-    std::string json = nodes[i]->RenderJsonString();
-    LOG(INFO) << json;
+  CHECK(node_after_end == nullptr);
+  return std::tuple(std::move(result), true);
+}
+
+WeakRefCountedPtr<BaseNode> ChannelzRegistry::InternalGet(intptr_t uuid) {
+  MutexLock index_lock(&index_mu_);
+  auto it = index_.find(uuid);
+  if (it == index_.end()) return nullptr;
+  BaseNode* node = it->second;
+  return node->WeakRefIfNonZero();
+}
+
+intptr_t ChannelzRegistry::InternalNumberNode(BaseNode* node) {
+  // node must be strongly owned still
+  node->AssertStronglyOwned();
+  const size_t node_shard_index = NodeShardIndex(node);
+  NodeShard& node_shard = node_shards_[node_shard_index];
+  MutexLock index_lock(&index_mu_);
+  MutexLock lock(&node_shard.mu);
+  intptr_t uuid = node->uuid_.load(std::memory_order_relaxed);
+  if (uuid != -1) return uuid;
+  uuid = uuid_generator_;
+  ++uuid_generator_;
+  node->uuid_ = uuid;
+  if (node->orphaned_index_ > 0) {
+    node_shard.orphaned.Remove(node);
+    node_shard.orphaned_numbered.AddToHead(node);
+  } else {
+    node_shard.nursery.Remove(node);
+    node_shard.numbered.AddToHead(node);
   }
+  index_.emplace(uuid, node);
+  return uuid;
+}
+
+bool ChannelzRegistry::NodeList::Holds(BaseNode* node) const {
+  BaseNode* n = head;
+  while (n != nullptr) {
+    if (n == node) return true;
+    n = n->next_;
+  }
+  return false;
+}
+
+void ChannelzRegistry::NodeList::AddToHead(BaseNode* node) {
+  DCHECK(!Holds(node));
+  ++count;
+  if (head != nullptr) head->prev_ = node;
+  node->next_ = head;
+  node->prev_ = nullptr;
+  head = node;
+  if (tail == nullptr) tail = node;
+  DCHECK(Holds(node));
+}
+
+void ChannelzRegistry::NodeList::Remove(BaseNode* node) {
+  DCHECK(Holds(node));
+  DCHECK_GT(count, 0u);
+  --count;
+  if (node->prev_ == nullptr) {
+    head = node->next_;
+    if (head == nullptr) {
+      DCHECK_EQ(count, 0u);
+      tail = nullptr;
+      DCHECK(!Holds(node));
+      return;
+    }
+  } else {
+    node->prev_->next_ = node->next_;
+  }
+  if (node->next_ == nullptr) {
+    tail = node->prev_;
+  } else {
+    node->next_->prev_ = node->prev_;
+  }
+  DCHECK(!Holds(node));
+}
+void ChannelzRegistry::TestOnlyReset() {
+  auto* p = Default();
+  p->uuid_generator_ = 1;
+  p->LoadConfig();
+  std::vector<WeakRefCountedPtr<BaseNode>> free_nodes;
+  for (size_t i = 0; i < kNodeShards; i++) {
+    MutexLock lock(&p->node_shards_[i].mu);
+    CHECK(p->node_shards_[i].nursery.head == nullptr);
+    CHECK(p->node_shards_[i].numbered.head == nullptr);
+    while (p->node_shards_[i].orphaned.head != nullptr) {
+      free_nodes.emplace_back(p->node_shards_[i].orphaned.head);
+      p->node_shards_[i].orphaned.Remove(p->node_shards_[i].orphaned.head);
+    }
+    while (p->node_shards_[i].orphaned_numbered.head != nullptr) {
+      free_nodes.emplace_back(p->node_shards_[i].orphaned_numbered.head);
+      p->node_shards_[i].orphaned_numbered.Remove(
+          p->node_shards_[i].orphaned_numbered.head);
+    }
+  }
+  std::vector<NodeShard> replace_node_shards(kNodeShards);
+  replace_node_shards.swap(p->node_shards_);
+  MutexLock lock(&p->index_mu_);
+  p->index_.clear();
 }
 
 }  // namespace channelz
@@ -179,21 +381,22 @@ void ChannelzRegistry::InternalLogAllEntities() {
 
 char* grpc_channelz_get_top_channels(intptr_t start_channel_id) {
   grpc_core::ExecCtx exec_ctx;
-  return gpr_strdup(
-      grpc_core::channelz::ChannelzRegistry::GetTopChannels(start_channel_id)
+  return grpc_core::channelz::ApplyHacks(
+      grpc_core::channelz::ChannelzRegistry::GetTopChannelsJson(
+          start_channel_id)
           .c_str());
 }
 
 char* grpc_channelz_get_servers(intptr_t start_server_id) {
   grpc_core::ExecCtx exec_ctx;
-  return gpr_strdup(
-      grpc_core::channelz::ChannelzRegistry::GetServers(start_server_id)
+  return grpc_core::channelz::ApplyHacks(
+      grpc_core::channelz::ChannelzRegistry::GetServersJson(start_server_id)
           .c_str());
 }
 
 char* grpc_channelz_get_server(intptr_t server_id) {
   grpc_core::ExecCtx exec_ctx;
-  grpc_core::RefCountedPtr<grpc_core::channelz::BaseNode> server_node =
+  grpc_core::WeakRefCountedPtr<grpc_core::channelz::BaseNode> server_node =
       grpc_core::channelz::ChannelzRegistry::Get(server_id);
   if (server_node == nullptr ||
       server_node->type() !=
@@ -203,7 +406,7 @@ char* grpc_channelz_get_server(intptr_t server_id) {
   grpc_core::Json json = grpc_core::Json::FromObject({
       {"server", server_node->RenderJson()},
   });
-  return gpr_strdup(grpc_core::JsonDump(json).c_str());
+  return grpc_core::channelz::ApplyHacks(grpc_core::JsonDump(json).c_str());
 }
 
 char* grpc_channelz_get_server_sockets(intptr_t server_id,
@@ -211,7 +414,7 @@ char* grpc_channelz_get_server_sockets(intptr_t server_id,
                                        intptr_t max_results) {
   grpc_core::ExecCtx exec_ctx;
   // Validate inputs before handing them of to the renderer.
-  grpc_core::RefCountedPtr<grpc_core::channelz::BaseNode> base_node =
+  grpc_core::WeakRefCountedPtr<grpc_core::channelz::BaseNode> base_node =
       grpc_core::channelz::ChannelzRegistry::Get(server_id);
   if (base_node == nullptr ||
       base_node->type() != grpc_core::channelz::BaseNode::EntityType::kServer ||
@@ -222,13 +425,13 @@ char* grpc_channelz_get_server_sockets(intptr_t server_id,
   // actually a server node.
   grpc_core::channelz::ServerNode* server_node =
       static_cast<grpc_core::channelz::ServerNode*>(base_node.get());
-  return gpr_strdup(
+  return grpc_core::channelz::ApplyHacks(
       server_node->RenderServerSockets(start_socket_id, max_results).c_str());
 }
 
 char* grpc_channelz_get_channel(intptr_t channel_id) {
   grpc_core::ExecCtx exec_ctx;
-  grpc_core::RefCountedPtr<grpc_core::channelz::BaseNode> channel_node =
+  grpc_core::WeakRefCountedPtr<grpc_core::channelz::BaseNode> channel_node =
       grpc_core::channelz::ChannelzRegistry::Get(channel_id);
   if (channel_node == nullptr ||
       (channel_node->type() !=
@@ -240,12 +443,12 @@ char* grpc_channelz_get_channel(intptr_t channel_id) {
   grpc_core::Json json = grpc_core::Json::FromObject({
       {"channel", channel_node->RenderJson()},
   });
-  return gpr_strdup(grpc_core::JsonDump(json).c_str());
+  return grpc_core::channelz::ApplyHacks(grpc_core::JsonDump(json).c_str());
 }
 
 char* grpc_channelz_get_subchannel(intptr_t subchannel_id) {
   grpc_core::ExecCtx exec_ctx;
-  grpc_core::RefCountedPtr<grpc_core::channelz::BaseNode> subchannel_node =
+  grpc_core::WeakRefCountedPtr<grpc_core::channelz::BaseNode> subchannel_node =
       grpc_core::channelz::ChannelzRegistry::Get(subchannel_id);
   if (subchannel_node == nullptr ||
       subchannel_node->type() !=
@@ -255,20 +458,22 @@ char* grpc_channelz_get_subchannel(intptr_t subchannel_id) {
   grpc_core::Json json = grpc_core::Json::FromObject({
       {"subchannel", subchannel_node->RenderJson()},
   });
-  return gpr_strdup(grpc_core::JsonDump(json).c_str());
+  return grpc_core::channelz::ApplyHacks(grpc_core::JsonDump(json).c_str());
 }
 
 char* grpc_channelz_get_socket(intptr_t socket_id) {
   grpc_core::ExecCtx exec_ctx;
-  grpc_core::RefCountedPtr<grpc_core::channelz::BaseNode> socket_node =
+  grpc_core::WeakRefCountedPtr<grpc_core::channelz::BaseNode> socket_node =
       grpc_core::channelz::ChannelzRegistry::Get(socket_id);
   if (socket_node == nullptr ||
-      socket_node->type() !=
-          grpc_core::channelz::BaseNode::EntityType::kSocket) {
+      (socket_node->type() !=
+           grpc_core::channelz::BaseNode::EntityType::kSocket &&
+       socket_node->type() !=
+           grpc_core::channelz::BaseNode::EntityType::kListenSocket)) {
     return nullptr;
   }
   grpc_core::Json json = grpc_core::Json::FromObject({
       {"socket", socket_node->RenderJson()},
   });
-  return gpr_strdup(grpc_core::JsonDump(json).c_str());
+  return grpc_core::channelz::ApplyHacks(grpc_core::JsonDump(json).c_str());
 }

src/core/channelz/channelz_registry.h

@@ -25,8 +25,10 @@
 #include <map>
 #include <string>
 
-#include "absl/base/thread_annotations.h"
+#include "absl/container/btree_map.h"
+#include "absl/functional/function_ref.h"
 #include "src/core/channelz/channelz.h"
+#include "src/core/util/json/json_writer.h"
 #include "src/core/util/ref_counted_ptr.h"
 #include "src/core/util/sync.h"
 
@@ -40,36 +42,134 @@ class ChannelzRegistry final {
   static void Register(BaseNode* node) {
     return Default()->InternalRegister(node);
   }
-  static void Unregister(intptr_t uuid) { Default()->InternalUnregister(uuid); }
-  static RefCountedPtr<BaseNode> Get(intptr_t uuid) {
+  static void Unregister(BaseNode* node) {
+    Default()->InternalUnregister(node);
+  }
+  static WeakRefCountedPtr<BaseNode> Get(intptr_t uuid) {
     return Default()->InternalGet(uuid);
   }
+  static intptr_t NumberNode(BaseNode* node) {
+    return Default()->InternalNumberNode(node);
+  }
+
+  static WeakRefCountedPtr<SubchannelNode> GetSubchannel(intptr_t uuid) {
+    return Default()
+        ->InternalGetTyped<SubchannelNode, BaseNode::EntityType::kSubchannel>(
+            uuid);
+  }
+
+  static WeakRefCountedPtr<ChannelNode> GetChannel(intptr_t uuid) {
+    auto node = Default()->InternalGet(uuid);
+    if (node == nullptr) return nullptr;
+    if (node->type() == BaseNode::EntityType::kTopLevelChannel) {
+      return node->WeakRefAsSubclass<ChannelNode>();
+    }
+    if (node->type() == BaseNode::EntityType::kInternalChannel) {
+      return node->WeakRefAsSubclass<ChannelNode>();
+    }
+    return nullptr;
+  }
+
+  static WeakRefCountedPtr<ServerNode> GetServer(intptr_t uuid) {
+    return Default()
+        ->InternalGetTyped<ServerNode, BaseNode::EntityType::kServer>(uuid);
+  }
+
+  static WeakRefCountedPtr<SocketNode> GetSocket(intptr_t uuid) {
+    return Default()
+        ->InternalGetTyped<SocketNode, BaseNode::EntityType::kSocket>(uuid);
+  }
 
   // Returns the allocated JSON string that represents the proto
   // GetTopChannelsResponse as per channelz.proto.
-  static std::string GetTopChannels(intptr_t start_channel_id) {
-    return Default()->InternalGetTopChannels(start_channel_id);
+  static auto GetTopChannels(intptr_t start_channel_id) {
+    return Default()
+        ->InternalGetObjects<ChannelNode,
+                             BaseNode::EntityType::kTopLevelChannel>(
+            start_channel_id);
   }
 
+  static std::string GetTopChannelsJson(intptr_t start_channel_id);
+  static std::string GetServersJson(intptr_t start_server_id);
+
   // Returns the allocated JSON string that represents the proto
   // GetServersResponse as per channelz.proto.
-  static std::string GetServers(intptr_t start_server_id) {
-    return Default()->InternalGetServers(start_server_id);
+  static auto GetServers(intptr_t start_server_id) {
+    return Default()
+        ->InternalGetObjects<ServerNode, BaseNode::EntityType::kServer>(
+            start_server_id);
+  }
+
+  static std::tuple<std::vector<WeakRefCountedPtr<BaseNode>>, bool>
+  GetChildrenOfType(intptr_t start_node, const BaseNode* parent,
+                    BaseNode::EntityType type, size_t max_results) {
+    return Default()->InternalGetChildrenOfType(start_node, parent, type,
+                                                max_results);
   }
 
   // Test only helper function to dump the JSON representation to std out.
   // This can aid in debugging channelz code.
   static void LogAllEntities() { Default()->InternalLogAllEntities(); }
 
-  // Test only helper function to reset to initial state.
-  static void TestOnlyReset() {
-    auto* p = Default();
-    MutexLock lock(&p->mu_);
-    p->node_map_.clear();
-    p->uuid_generator_ = 0;
+  static std::vector<WeakRefCountedPtr<BaseNode>> GetAllEntities() {
+    return Default()->InternalGetAllEntities();
   }
 
+  // Test only helper function to reset to initial state.
+  static void TestOnlyReset();
+
  private:
+  ChannelzRegistry() { LoadConfig(); }
+
+  void LoadConfig();
+
+  // Takes a callable F: (WeakRefCountedPtr<BaseNode>) -> bool, and returns
+  // a (BaseNode*) -> bool that filters unreffed objects and returns true.
+  // The ref must be unreffed outside the NodeMapInterface iteration.
+  template <typename F>
+  static auto CollectReferences(F fn) {
+    return [fn = std::move(fn)](BaseNode* n) {
+      auto node = n->RefIfNonZero();
+      if (node == nullptr) return true;
+      return fn(std::move(node));
+    };
+  }
+
+  struct NodeList {
+    BaseNode* head = nullptr;
+    BaseNode* tail = nullptr;
+    size_t count = 0;
+    bool Holds(BaseNode* node) const;
+    void AddToHead(BaseNode* node);
+    void Remove(BaseNode* node);
+  };
+  // Nodes traverse through up to four lists, depending on
+  // whether they have a uuid (this is becoming numbered),
+  // and whether they have been orphaned or not.
+  // The lists help us find un-numbered nodes when needed for
+  // queries, and the oldest orphaned node when needed for
+  // garbage collection.
+  // Nodes are organized into shards based on their pointer
+  // address. A shard tracks the four lists of nodes
+  // independently - we strive to have no cross-talk between
+  // shards as these are very global objects.
+  struct alignas(GPR_CACHELINE_SIZE) NodeShard {
+    Mutex mu;
+    // Nursery nodes have no uuid and are not orphaned.
+    NodeList nursery ABSL_GUARDED_BY(mu);
+    // Numbered nodes have been assigned a uuid, and are not orphaned.
+    NodeList numbered ABSL_GUARDED_BY(mu);
+    // Orphaned nodes have no uuid, but have been orphaned.
+    NodeList orphaned ABSL_GUARDED_BY(mu);
+    // Finally, orphaned numbered nodes are orphaned, and have been assigned a
+    // uuid.
+    NodeList orphaned_numbered ABSL_GUARDED_BY(mu);
+    uint64_t next_orphan_index ABSL_GUARDED_BY(mu) = 1;
+    size_t TotalOrphaned() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu) {
+      return orphaned.count + orphaned_numbered.count;
+    }
+  };
+
   // Returned the singleton instance of ChannelzRegistry;
   static ChannelzRegistry* Default();
 
@@ -78,23 +178,81 @@ class ChannelzRegistry final {
 
   // globally unregisters the object that is associated to uuid. Also does
   // sanity check that an object doesn't try to unregister the wrong type.
-  void InternalUnregister(intptr_t uuid);
+  void InternalUnregister(BaseNode* node);
+
+  intptr_t InternalNumberNode(BaseNode* node);
 
   // if object with uuid has previously been registered as the correct type,
   // returns the void* associated with that uuid. Else returns nullptr.
-  RefCountedPtr<BaseNode> InternalGet(intptr_t uuid);
+  WeakRefCountedPtr<BaseNode> InternalGet(intptr_t uuid);
 
-  std::string InternalGetTopChannels(intptr_t start_channel_id);
-  std::string InternalGetServers(intptr_t start_server_id);
+  // Generic query over nodes.
+  // This function takes care of all the gnarly locking, and allows high level
+  // code to request a start node and maximum number of results (for pagination
+  // purposes).
+  // `discriminator` allows callers to choose which nodes will be returned - if
+  // it returns true, the node is included in the result.
+  // `discriminator` *MUST NOT* ref the node, nor call into ChannelzRegistry via
+  // any code path (locks are held during the call).
+  std::tuple<std::vector<WeakRefCountedPtr<BaseNode>>, bool> QueryNodes(
+      intptr_t start_node,
+      absl::FunctionRef<bool(const BaseNode*)> discriminator,
+      size_t max_results);
+
+  std::tuple<std::vector<WeakRefCountedPtr<BaseNode>>, bool>
+  InternalGetChildrenOfType(intptr_t start_node, const BaseNode* parent,
+                            BaseNode::EntityType type, size_t max_results) {
+    return QueryNodes(
+        start_node,
+        [type, parent](const BaseNode* n) {
+          return n->type() == type && n->HasParent(parent);
+        },
+        max_results);
+  }
+
+  template <typename T, BaseNode::EntityType entity_type>
+  WeakRefCountedPtr<T> InternalGetTyped(intptr_t uuid) {
+    WeakRefCountedPtr<BaseNode> node = InternalGet(uuid);
+    if (node == nullptr || node->type() != entity_type) {
+      return nullptr;
+    }
+    return node->WeakRefAsSubclass<T>();
+  }
+
+  template <typename T, BaseNode::EntityType entity_type>
+  std::tuple<std::vector<WeakRefCountedPtr<T>>, bool> InternalGetObjects(
+      intptr_t start_id) {
+    const int kPaginationLimit = 100;
+    std::vector<WeakRefCountedPtr<T>> top_level_channels;
+    const auto [nodes, end] = QueryNodes(
+        start_id,
+        [](const BaseNode* node) { return node->type() == entity_type; },
+        kPaginationLimit);
+    for (const auto& p : nodes) {
+      top_level_channels.emplace_back(p->template WeakRefAsSubclass<T>());
+    }
+    return std::tuple(std::move(top_level_channels), end);
+  }
 
   void InternalLogAllEntities();
+  std::vector<WeakRefCountedPtr<BaseNode>> InternalGetAllEntities();
 
-  // protects members
-  Mutex mu_;
-  std::map<intptr_t, BaseNode*> node_map_ ABSL_GUARDED_BY(mu_);
-  intptr_t uuid_generator_ ABSL_GUARDED_BY(mu_) = 0;
+  static constexpr size_t kNodeShards = 63;
+  size_t NodeShardIndex(BaseNode* node) {
+    return absl::HashOf(node) % kNodeShards;
+  }
+
+  int64_t uuid_generator_{1};
+  std::vector<NodeShard> node_shards_{kNodeShards};
+  Mutex index_mu_;
+  absl::btree_map<intptr_t, BaseNode*> index_ ABSL_GUARDED_BY(index_mu_);
+  size_t max_orphaned_per_shard_;
 };
 
+// `additionalInfo` section is not yet in the protobuf format, so we
+// provide a utility to strip it for compatibility.
+std::string StripAdditionalInfoFromJson(absl::string_view json);
+
 }  // namespace channelz
 }  // namespace grpc_core
 

src/core/channelz/ztrace_collector.h

@@ -0,0 +1,315 @@
+// Copyright 2025 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef GRPC_SRC_CORE_CHANNELZ_ZTRACE_COLLECTOR_H
+#define GRPC_SRC_CORE_CHANNELZ_ZTRACE_COLLECTOR_H
+
+#include <grpc/support/time.h>
+
+#include <memory>
+#include <tuple>
+#include <vector>
+
+#include "absl/container/flat_hash_set.h"
+#include "src/core/channelz/channelz.h"
+#include "src/core/lib/debug/trace.h"
+#include "src/core/util/json/json_writer.h"
+#include "src/core/util/single_set_ptr.h"
+#include "src/core/util/string.h"
+#include "src/core/util/sync.h"
+#include "src/core/util/time.h"
+
+#ifdef GRPC_NO_ZTRACE
+namespace grpc_core::channelz {
+namespace ztrace_collector_detail {
+class ZTraceImpl final : public ZTrace {
+ public:
+  explicit ZTraceImpl() {}
+
+  void Run(Timestamp deadline, std::map<std::string, std::string> args,
+           std::shared_ptr<grpc_event_engine::experimental::EventEngine>
+               event_engine,
+           absl::AnyInvocable<void(Json)> callback) override {
+    event_engine->Run([callback = std::move(callback)]() mutable {
+      callback(Json::FromBool(false));
+    });
+  }
+};
+
+class StubImpl {
+ public:
+  template <typename T>
+  void Append(const T&) {}
+
+  std::unique_ptr<ZTrace> MakeZTrace() {
+    return std::make_unique<ZTraceImpl>();
+  }
+};
+}  // namespace ztrace_collector_detail
+
+template <typename...>
+class ZTraceCollector : public ztrace_collector_detail::StubImpl {};
+}  // namespace grpc_core::channelz
+#else
+namespace grpc_core::channelz {
+namespace ztrace_collector_detail {
+
+template <typename T>
+using Collection = std::deque<std::pair<gpr_cycle_counter, T> >;
+
+template <typename T>
+void AppendResults(const Collection<T>& data, Json::Array& results) {
+  for (const auto& value : data) {
+    Json::Object object;
+    object["timestamp"] =
+        Json::FromString(gpr_format_timespec(gpr_convert_clock_type(
+            gpr_cycle_counter_to_time(value.first), GPR_CLOCK_REALTIME)));
+    value.second.RenderJson(object);
+    results.emplace_back(Json::FromObject(std::move(object)));
+  }
+}
+
+template <typename Needle, typename... Haystack>
+constexpr bool kIsElement = false;
+
+template <typename Needle, typename... Haystack>
+constexpr bool kIsElement<Needle, Needle, Haystack...> = true;
+
+template <typename Needle, typename H, typename... Haystack>
+constexpr bool kIsElement<Needle, H, Haystack...> =
+    kIsElement<Needle, Haystack...>;
+
+}  // namespace ztrace_collector_detail
+
+inline std::optional<int64_t> IntFromArgs(
+    const std::map<std::string, std::string>& args, const std::string& name) {
+  auto it = args.find(name);
+  if (it == args.end()) return std::nullopt;
+  int64_t out;
+  if (!absl::SimpleAtoi(it->second, &out)) return std::nullopt;
+  return out;
+}
+
+// Generic collector infrastructure for ztrace queries.
+// Abstracts away most of the ztrace requirements in an efficient manner,
+// allowing system authors to concentrate on emitting useful data.
+// If no trace is performed, overhead is one pointer and one relaxed atomic read
+// per trace event.
+//
+// Two kinds of objects are required:
+// 1. A `Config`
+//    - This type should be constructible with a std::map<std::string,
+//    std::string>
+//      and provides overall query configuration - the map can be used to pull
+//      predicates from the calling system.
+//    - Needs a `bool Finishes(T)` method for each Data type (see 2).
+//      This allows the config to terminate a query in the event of reaching
+//      some configured predicate.
+// 2. N `Data` types
+//    - One for each kind of data captured in the trace
+//    - Allows avoiding e.g. variant<> data types; these are inefficient
+//      in this context because they force every recorded entry to use the
+//      same number of bytes whilst pending.
+template <typename Config, typename... Data>
+class ZTraceCollector {
+ public:
+  template <typename X>
+  void Append(X producer_or_value) {
+    GRPC_TRACE_LOG(ztrace, INFO) << "ZTRACE[" << this << "]: " << [&]() {
+      Json::Object obj;
+      if constexpr (ztrace_collector_detail::kIsElement<X, Data...>) {
+        producer_or_value.RenderJson(obj);
+      } else {
+        producer_or_value().RenderJson(obj);
+      }
+      return JsonDump(Json::FromObject(std::move(obj)));
+    }();
+    if (!impl_.is_set()) return;
+    if constexpr (ztrace_collector_detail::kIsElement<X, Data...>) {
+      AppendValue(std::move(producer_or_value));
+    } else {
+      AppendValue(producer_or_value());
+    }
+  }
+
+  std::unique_ptr<ZTrace> MakeZTrace() {
+    return std::make_unique<ZTraceImpl>(impl_.GetOrCreate());
+  }
+
+ private:
+  template <typename T>
+  using Collection = ztrace_collector_detail::Collection<T>;
+
+  struct Instance : public RefCounted<Instance> {
+    Instance(std::map<std::string, std::string> args,
+             std::shared_ptr<grpc_event_engine::experimental::EventEngine>
+                 event_engine,
+             absl::AnyInvocable<void(Json)> done)
+        : memory_cap_(IntFromArgs(args, "memory_cap").value_or(1024 * 1024)),
+          config(args),
+          event_engine(std::move(event_engine)),
+          done(std::move(done)) {}
+    using Collections = std::tuple<Collection<Data>...>;
+    struct RemoveMostRecentState {
+      void (*enact)(Instance*) = nullptr;
+      gpr_cycle_counter most_recent =
+          std::numeric_limits<gpr_cycle_counter>::max();
+    };
+    template <typename T>
+    void Append(std::pair<gpr_cycle_counter, T> value) {
+      memory_used_ += value.second.MemoryUsage();
+      while (memory_used_ > memory_cap_) RemoveMostRecent();
+      std::get<Collection<T> >(data).push_back(std::move(value));
+    }
+    void RemoveMostRecent() {
+      RemoveMostRecentState state;
+      (UpdateRemoveMostRecentState<Data>(&state), ...);
+      CHECK(state.enact != nullptr);
+      state.enact(this);
+      ++items_removed_;
+    }
+    template <typename T>
+    void UpdateRemoveMostRecentState(RemoveMostRecentState* state) {
+      auto& collection = std::get<Collection<T> >(data);
+      if (collection.empty()) return;
+      if (state->enact == nullptr ||
+          collection.front().first < state->most_recent) {
+        state->enact = +[](Instance* instance) {
+          auto& collection = std::get<Collection<T> >(instance->data);
+          const size_t ent_usage = collection.front().second.MemoryUsage();
+          CHECK_GE(instance->memory_used_, ent_usage);
+          instance->memory_used_ -= ent_usage;
+          collection.pop_front();
+        };
+        state->most_recent = collection.front().first;
+      }
+    }
+    void Finish(absl::Status status) {
+      event_engine->Run([data = std::move(data), done = std::move(done),
+                         status = std::move(status), memory_used = memory_used_,
+                         items_removed = items_removed_]() mutable {
+        Json::Array entries;
+        (ztrace_collector_detail::AppendResults(
+             std::get<Collection<Data> >(data), entries),
+         ...);
+        Json::Object result;
+        result["entries"] = Json::FromArray(entries);
+        result["status"] = Json::FromString(status.ToString());
+        result["memory_used"] =
+            Json::FromNumber(static_cast<uint64_t>(memory_used));
+        result["items_removed"] = Json::FromNumber(items_removed);
+        done(Json::FromObject(std::move(result)));
+      });
+    }
+    size_t memory_used_ = 0;
+    size_t memory_cap_ = 0;
+    uint64_t items_removed_ = 0;
+    Config config;
+    const Timestamp start_time = Timestamp::Now();
+    std::shared_ptr<grpc_event_engine::experimental::EventEngine> event_engine;
+    grpc_event_engine::experimental::EventEngine::TaskHandle task_handle{
+        grpc_event_engine::experimental::EventEngine::TaskHandle::kInvalid};
+    Collections data;
+    absl::AnyInvocable<void(Json)> done;
+  };
+  struct Impl : public RefCounted<Impl> {
+    Mutex mu;
+    absl::flat_hash_set<RefCountedPtr<Instance> > instances ABSL_GUARDED_BY(mu);
+  };
+  class ZTraceImpl final : public ZTrace {
+   public:
+    explicit ZTraceImpl(RefCountedPtr<Impl> impl) : impl_(std::move(impl)) {}
+
+    void Run(Timestamp deadline, std::map<std::string, std::string> args,
+             std::shared_ptr<grpc_event_engine::experimental::EventEngine>
+                 event_engine,
+             absl::AnyInvocable<void(Json)> callback) override {
+      auto instance = MakeRefCounted<Instance>(std::move(args), event_engine,
+                                               std::move(callback));
+      auto impl = std::move(impl_);
+      RefCountedPtr<Instance> oldest_instance;
+      MutexLock lock(&impl->mu);
+      if (impl->instances.size() > 20) {
+        // Eject oldest running trace
+        Timestamp oldest_time = Timestamp::InfFuture();
+        for (auto& instance : impl->instances) {
+          if (instance->start_time < oldest_time) {
+            oldest_time = instance->start_time;
+            oldest_instance = instance;
+          }
+        }
+        CHECK(oldest_instance != nullptr);
+        impl->instances.erase(oldest_instance);
+        oldest_instance->Finish(
+            absl::ResourceExhaustedError("Too many concurrent ztrace queries"));
+      }
+      instance->task_handle = event_engine->RunAfter(
+          deadline - Timestamp::Now(), [instance, impl]() {
+            bool finish;
+            {
+              MutexLock lock(&impl->mu);
+              finish = impl->instances.erase(instance);
+            }
+            if (finish) instance->Finish(absl::DeadlineExceededError(""));
+          });
+      impl->instances.insert(instance);
+    }
+
+   private:
+    RefCountedPtr<Impl> impl_;
+  };
+
+  template <typename T>
+  void AppendValue(T&& data) {
+    auto value = std::pair(gpr_get_cycle_counter(), std::forward<T>(data));
+    auto* impl = impl_.Get();
+    {
+      MutexLock lock(&impl->mu);
+      switch (impl->instances.size()) {
+        case 0:
+          return;
+        case 1: {
+          auto& instances = impl->instances;
+          auto& instance = *instances.begin();
+          const bool finishes = instance->config.Finishes(value.second);
+          instance->Append(std::move(value));
+          if (finishes) {
+            instance->Finish(absl::OkStatus());
+            instances.clear();
+          }
+        } break;
+        default: {
+          std::vector<RefCountedPtr<Instance> > finished;
+          for (auto& instance : impl->instances) {
+            const bool finishes = instance->config.Finishes(value.second);
+            instance->Append(value);
+            if (finishes) {
+              finished.push_back(instance);
+            }
+          }
+          for (const auto& instance : finished) {
+            instance->Finish(absl::OkStatus());
+            impl->instances.erase(instance);
+          }
+        }
+      }
+    }
+  }
+
+  SingleSetRefCountedPtr<Impl> impl_;
+};
+}  // namespace grpc_core::channelz
+#endif  // GRPC_NO_ZTRACE
+
+#endif  // GRPC_SRC_CORE_CHANNELZ_ZTRACE_COLLECTOR_H

src/core/client_channel/backup_poller.cc

@@ -62,10 +62,15 @@ static grpc_core::Duration g_poll_interval =
 static bool g_backup_polling_disabled;
 
 void grpc_client_channel_global_init_backup_polling() {
+#ifndef GRPC_DO_NOT_INSTANTIATE_POSIX_POLLER
   // Disable backup polling if EventEngine is used everywhere.
   g_backup_polling_disabled = grpc_core::IsEventEngineClientEnabled() &&
                               grpc_core::IsEventEngineListenerEnabled() &&
                               grpc_core::IsEventEngineDnsEnabled();
+#else
+  // EventEngine polling not supported, keep using the backup poller.
+  g_backup_polling_disabled = false;
+#endif
   if (g_backup_polling_disabled) {
     return;
   }
@@ -155,11 +160,21 @@ static void g_poller_init_locked() {
   }
 }
 
+static bool g_can_poll_in_background() {
+#ifndef GRPC_DO_NOT_INSTANTIATE_POSIX_POLLER
+  return grpc_iomgr_run_in_background();
+#else
+  // No iomgr "event_engines" (not to be confused with the new EventEngine)
+  // are able to run in backgroung.
+  return false;
+#endif
+}
+
 void grpc_client_channel_start_backup_polling(
     grpc_pollset_set* interested_parties) {
   if (g_backup_polling_disabled ||
       g_poll_interval == grpc_core::Duration::Zero() ||
-      grpc_iomgr_run_in_background()) {
+      g_can_poll_in_background()) {
     return;
   }
   gpr_mu_lock(&g_poller_mu);
@@ -179,7 +194,7 @@ void grpc_client_channel_stop_backup_polling(
     grpc_pollset_set* interested_parties) {
   if (g_backup_polling_disabled ||
       g_poll_interval == grpc_core::Duration::Zero() ||
-      grpc_iomgr_run_in_background()) {
+      g_can_poll_in_background()) {
     return;
   }
   grpc_pollset_set_del_pollset(interested_parties, g_poller->pollset);

src/core/client_channel/client_channel.cc

@@ -228,21 +228,19 @@ class ClientChannel::SubchannelWrapper::WatcherWrapper
     subchannel_wrapper_.reset(DEBUG_LOCATION, "WatcherWrapper");
   }
 
-  void OnConnectivityStateChange(
-      RefCountedPtr<ConnectivityStateWatcherInterface> self,
-      grpc_connectivity_state state, const absl::Status& status) override {
+  void OnConnectivityStateChange(grpc_connectivity_state state,
+                                 const absl::Status& status) override {
     GRPC_TRACE_LOG(client_channel, INFO)
         << "client_channel=" << subchannel_wrapper_->client_channel_.get()
         << ": connectivity change for subchannel wrapper "
         << subchannel_wrapper_.get() << " subchannel "
         << subchannel_wrapper_->subchannel_.get()
         << "; hopping into work_serializer";
-    self.release();  // Held by callback.
+    auto self = RefAsSubclass<WatcherWrapper>();
     subchannel_wrapper_->client_channel_->work_serializer_->Run(
-        [this, state, status]() ABSL_EXCLUSIVE_LOCKS_REQUIRED(
-            *subchannel_wrapper_->client_channel_->work_serializer_) {
-          ApplyUpdateInControlPlaneWorkSerializer(state, status);
-          Unref();
+        [self, state, status]() ABSL_EXCLUSIVE_LOCKS_REQUIRED(
+            *self->subchannel_wrapper_->client_channel_->work_serializer_) {
+          self->ApplyUpdateInControlPlaneWorkSerializer(state, status);
         });
   }
 
@@ -324,8 +322,7 @@ ClientChannel::SubchannelWrapper::SubchannelWrapper(
       auto it =
           client_channel_->subchannel_refcount_map_.find(subchannel_.get());
       if (it == client_channel_->subchannel_refcount_map_.end()) {
-        client_channel_->channelz_node_->AddChildSubchannel(
-            subchannel_node->uuid());
+        subchannel_node->AddParent(client_channel_->channelz_node_);
         it = client_channel_->subchannel_refcount_map_
                  .emplace(subchannel_.get(), 0)
                  .first;
@@ -360,8 +357,8 @@ void ClientChannel::SubchannelWrapper::Orphaned() {
             CHECK(it != self->client_channel_->subchannel_refcount_map_.end());
             --it->second;
             if (it->second == 0) {
-              self->client_channel_->channelz_node_->RemoveChildSubchannel(
-                  subchannel_node->uuid());
+              subchannel_node->RemoveParent(
+                  self->client_channel_->channelz_node_);
               self->client_channel_->subchannel_refcount_map_.erase(it);
             }
           }
@@ -530,7 +527,11 @@ RefCountedPtr<SubchannelPoolInterface> GetSubchannelPool(
   if (args.GetBool(GRPC_ARG_USE_LOCAL_SUBCHANNEL_POOL).value_or(false)) {
     return MakeRefCounted<LocalSubchannelPool>();
   }
-  return GlobalSubchannelPool::instance();
+  if (IsShardGlobalConnectionPoolEnabled()) {
+    return GlobalSubchannelPool::instance();
+  } else {
+    return LegacyGlobalSubchannelPool::instance();
+  }
 }
 
 }  // namespace
@@ -701,6 +702,7 @@ class ExternalStateWatcher : public RefCounted<ExternalStateWatcher> {
                        grpc_connectivity_state last_observed_state,
                        Timestamp deadline)
       : channel_(std::move(channel)), cq_(cq), tag_(tag) {
+    grpc_cq_begin_op(cq, tag);
     MutexLock lock(&mu_);
     // Start watch.  This inherits the ref from creation.
     auto watcher =
@@ -780,17 +782,14 @@ void ClientChannel::WatchConnectivityState(grpc_connectivity_state state,
 }
 
 void ClientChannel::AddConnectivityWatcher(
-    grpc_connectivity_state,
-    OrphanablePtr<AsyncConnectivityStateWatcherInterface>) {
-  Crash("not implemented");
-  // TODO(ctiller): to make this work, need to change WorkSerializer to use
-  // absl::AnyInvocable<> instead of std::function<>
-  //  work_serializer_->Run(
-  //      [self = RefAsSubclass<ClientChannel>(), initial_state,
-  //       watcher = std::move(watcher)]()
-  //            ABSL_EXCLUSIVE_LOCKS_REQUIRED(*work_serializer_) {
-  //        self->state_tracker_.AddWatcher(initial_state, std::move(watcher));
-  //      });
+    grpc_connectivity_state initial_state,
+    OrphanablePtr<AsyncConnectivityStateWatcherInterface> watcher) {
+  auto self = RefAsSubclass<ClientChannel>();
+  work_serializer_->Run(
+      [self, initial_state, watcher = std::move(watcher)]()
+          ABSL_EXCLUSIVE_LOCKS_REQUIRED(*self->work_serializer_) mutable {
+            self->state_tracker_.AddWatcher(initial_state, std::move(watcher));
+          });
 }
 
 void ClientChannel::RemoveConnectivityWatcher(
@@ -1320,11 +1319,13 @@ void ClientChannel::UpdateStateLocked(grpc_connectivity_state state,
   state_tracker_.SetState(state, status, reason);
   if (channelz_node_ != nullptr) {
     channelz_node_->SetConnectivityState(state);
-    channelz_node_->AddTraceEvent(
-        channelz::ChannelTrace::Severity::Info,
-        grpc_slice_from_static_string(
-            channelz::ChannelNode::GetChannelConnectivityStateChangeString(
-                state)));
+    std::string trace =
+        channelz::ChannelNode::GetChannelConnectivityStateChangeString(state);
+    if (!status.ok() || state == GRPC_CHANNEL_TRANSIENT_FAILURE) {
+      absl::StrAppend(&trace, " status:", status.ToString());
+    }
+    channelz_node_->AddTraceEvent(channelz::ChannelTrace::Severity::Info,
+                                  grpc_slice_from_cpp_string(std::move(trace)));
   }
 }
 

src/core/client_channel/client_channel_filter.cc

@@ -501,7 +501,7 @@ class ClientChannelFilter::SubchannelWrapper final
       if (subchannel_node != nullptr) {
         auto it = chand_->subchannel_refcount_map_.find(subchannel_.get());
         if (it == chand_->subchannel_refcount_map_.end()) {
-          chand_->channelz_node_->AddChildSubchannel(subchannel_node->uuid());
+          subchannel_node->AddParent(chand_->channelz_node_);
           it = chand_->subchannel_refcount_map_.emplace(subchannel_.get(), 0)
                    .first;
         }
@@ -533,8 +533,7 @@ class ClientChannelFilter::SubchannelWrapper final
           CHECK(it != chand_->subchannel_refcount_map_.end());
           --it->second;
           if (it->second == 0) {
-            chand_->channelz_node_->RemoveChildSubchannel(
-                subchannel_node->uuid());
+            subchannel_node->RemoveParent(chand_->channelz_node_);
             chand_->subchannel_refcount_map_.erase(it);
           }
         }
@@ -617,20 +616,18 @@ class ClientChannelFilter::SubchannelWrapper final
       parent_.reset(DEBUG_LOCATION, "WatcherWrapper");
     }
 
-    void OnConnectivityStateChange(
-        RefCountedPtr<ConnectivityStateWatcherInterface> self,
-        grpc_connectivity_state state, const absl::Status& status) override {
+    void OnConnectivityStateChange(grpc_connectivity_state state,
+                                   const absl::Status& status) override {
       GRPC_TRACE_LOG(client_channel, INFO)
           << "chand=" << parent_->chand_
           << ": connectivity change for subchannel wrapper " << parent_.get()
           << " subchannel " << parent_->subchannel_.get()
           << "hopping into work_serializer";
-      self.release();  // Held by callback.
+      auto self = RefAsSubclass<WatcherWrapper>();
       parent_->chand_->work_serializer_->Run(
-          [this, state, status]() ABSL_EXCLUSIVE_LOCKS_REQUIRED(
-              *parent_->chand_->work_serializer_) {
-            ApplyUpdateInControlPlaneWorkSerializer(state, status);
-            Unref();
+          [self, state, status]() ABSL_EXCLUSIVE_LOCKS_REQUIRED(
+              *self->parent_->chand_->work_serializer_) {
+            self->ApplyUpdateInControlPlaneWorkSerializer(state, status);
           });
     }
 
@@ -1029,7 +1026,11 @@ RefCountedPtr<SubchannelPoolInterface> GetSubchannelPool(
   if (args.GetBool(GRPC_ARG_USE_LOCAL_SUBCHANNEL_POOL).value_or(false)) {
     return MakeRefCounted<LocalSubchannelPool>();
   }
-  return GlobalSubchannelPool::instance();
+  if (IsShardGlobalConnectionPoolEnabled()) {
+    return GlobalSubchannelPool::instance();
+  } else {
+    return LegacyGlobalSubchannelPool::instance();
+  }
 }
 
 }  // namespace
@@ -1551,11 +1552,13 @@ void ClientChannelFilter::UpdateStateLocked(grpc_connectivity_state state,
   state_tracker_.SetState(state, status, reason);
   if (channelz_node_ != nullptr) {
     channelz_node_->SetConnectivityState(state);
-    channelz_node_->AddTraceEvent(
-        channelz::ChannelTrace::Severity::Info,
-        grpc_slice_from_static_string(
-            channelz::ChannelNode::GetChannelConnectivityStateChangeString(
-                state)));
+    std::string trace =
+        channelz::ChannelNode::GetChannelConnectivityStateChangeString(state);
+    if (!status.ok() || state == GRPC_CHANNEL_TRANSIENT_FAILURE) {
+      absl::StrAppend(&trace, " status:", status.ToString());
+    }
+    channelz_node_->AddTraceEvent(channelz::ChannelTrace::Severity::Info,
+                                  grpc_slice_from_cpp_string(std::move(trace)));
   }
 }
 
@@ -2428,9 +2431,7 @@ void ClientChannelFilter::LoadBalancedCall::RecordCallCompletion(
 void ClientChannelFilter::LoadBalancedCall::RecordLatency() {
   // Compute latency and report it to the tracer.
   if (call_attempt_tracer() != nullptr) {
-    gpr_timespec latency =
-        gpr_cycle_counter_sub(gpr_get_cycle_counter(), lb_call_start_time_);
-    call_attempt_tracer()->RecordEnd(latency);
+    call_attempt_tracer()->RecordEnd();
   }
 }
 

src/core/client_channel/client_channel_filter.h

@@ -438,8 +438,6 @@ class ClientChannelFilter::LoadBalancedCall
 
   absl::AnyInvocable<void()> on_commit_;
 
-  gpr_cycle_counter lb_call_start_time_ = gpr_get_cycle_counter();
-
   RefCountedPtr<ConnectedSubchannel> connected_subchannel_;
   const BackendMetricData* backend_metric_data_ = nullptr;
   std::unique_ptr<LoadBalancingPolicy::SubchannelCallTrackerInterface>

src/core/client_channel/connector.h

@@ -53,8 +53,6 @@ class SubchannelConnector : public InternallyRefCounted<SubchannelConnector> {
     Transport* transport = nullptr;
     // Channel args to be passed to filters.
     ChannelArgs channel_args;
-    // Channelz socket node of the connected transport, if any.
-    RefCountedPtr<channelz::SocketNode> socket_node;
 
     void Reset() {
       if (transport != nullptr) {
@@ -62,7 +60,6 @@ class SubchannelConnector : public InternallyRefCounted<SubchannelConnector> {
         transport = nullptr;
       }
       channel_args = ChannelArgs();
-      socket_node.reset();
     }
   };
 

src/core/client_channel/global_subchannel_pool.cc

@@ -26,12 +26,13 @@
 
 namespace grpc_core {
 
-RefCountedPtr<GlobalSubchannelPool> GlobalSubchannelPool::instance() {
-  static GlobalSubchannelPool* p = new GlobalSubchannelPool();
-  return p->RefAsSubclass<GlobalSubchannelPool>();
+RefCountedPtr<LegacyGlobalSubchannelPool>
+LegacyGlobalSubchannelPool::instance() {
+  static LegacyGlobalSubchannelPool* p = new LegacyGlobalSubchannelPool();
+  return p->RefAsSubclass<LegacyGlobalSubchannelPool>();
 }
 
-RefCountedPtr<Subchannel> GlobalSubchannelPool::RegisterSubchannel(
+RefCountedPtr<Subchannel> LegacyGlobalSubchannelPool::RegisterSubchannel(
     const SubchannelKey& key, RefCountedPtr<Subchannel> constructed) {
   MutexLock lock(&mu_);
   auto it = subchannel_map_.find(key);
@@ -43,8 +44,8 @@ RefCountedPtr<Subchannel> GlobalSubchannelPool::RegisterSubchannel(
   return constructed;
 }
 
-void GlobalSubchannelPool::UnregisterSubchannel(const SubchannelKey& key,
-                                                Subchannel* subchannel) {
+void LegacyGlobalSubchannelPool::UnregisterSubchannel(const SubchannelKey& key,
+                                                      Subchannel* subchannel) {
   MutexLock lock(&mu_);
   auto it = subchannel_map_.find(key);
   // delete only if key hasn't been re-registered to a different subchannel
@@ -54,7 +55,7 @@ void GlobalSubchannelPool::UnregisterSubchannel(const SubchannelKey& key,
   }
 }
 
-RefCountedPtr<Subchannel> GlobalSubchannelPool::FindSubchannel(
+RefCountedPtr<Subchannel> LegacyGlobalSubchannelPool::FindSubchannel(
     const SubchannelKey& key) {
   MutexLock lock(&mu_);
   auto it = subchannel_map_.find(key);
@@ -62,4 +63,64 @@ RefCountedPtr<Subchannel> GlobalSubchannelPool::FindSubchannel(
   return it->second->RefIfNonZero();
 }
 
+RefCountedPtr<GlobalSubchannelPool> GlobalSubchannelPool::instance() {
+  static GlobalSubchannelPool* p = new GlobalSubchannelPool();
+  return p->RefAsSubclass<GlobalSubchannelPool>();
+}
+
+RefCountedPtr<Subchannel> GlobalSubchannelPool::RegisterSubchannel(
+    const SubchannelKey& key, RefCountedPtr<Subchannel> constructed) {
+  auto shard_index = ShardIndex(key);
+  auto& write_shard = write_shards_[shard_index];
+  auto& read_shard = read_shards_[shard_index];
+  SubchannelMap old_map1;
+  SubchannelMap old_map2;
+  MutexLock lock(&write_shard.mu);
+  auto* existing = write_shard.map.Lookup(key);
+  if (existing != nullptr) return (*existing)->RefIfNonZero();
+  old_map1 = std::exchange(write_shard.map,
+                           write_shard.map.Add(key, constructed->WeakRef()));
+  MutexLock lock_read(&read_shard.mu);
+  old_map2 = std::exchange(read_shard.map, write_shard.map);
+  return constructed;
+}
+
+void GlobalSubchannelPool::UnregisterSubchannel(const SubchannelKey& key,
+                                                Subchannel* subchannel) {
+  auto shard_index = ShardIndex(key);
+  auto& write_shard = write_shards_[shard_index];
+  auto& read_shard = read_shards_[shard_index];
+  SubchannelMap old_map1;
+  SubchannelMap old_map2;
+  MutexLock lock(&write_shard.mu);
+  auto* existing = write_shard.map.Lookup(key);
+  // delete only if key hasn't been re-registered to a different subchannel
+  // between strong-unreffing and unregistration of subchannel.
+  if (existing == nullptr || existing->get() != subchannel) return;
+  old_map1 = std::exchange(write_shard.map, write_shard.map.Remove(key));
+  MutexLock lock_read(&read_shard.mu);
+  old_map2 = std::exchange(read_shard.map, write_shard.map);
+}
+
+RefCountedPtr<Subchannel> GlobalSubchannelPool::FindSubchannel(
+    const SubchannelKey& key) {
+  auto shard_index = ShardIndex(key);
+  auto& read_shard = read_shards_[shard_index];
+  read_shard.mu.Lock();
+  auto map = read_shard.map;
+  read_shard.mu.Unlock();
+  auto* subchannel = map.Lookup(key);
+  if (subchannel == nullptr) return nullptr;
+  return (*subchannel)->RefIfNonZero();
+}
+
+size_t GlobalSubchannelPool::ShardIndex(const SubchannelKey& key) {
+  absl::string_view addr(key.address().addr, key.address().len);
+  return absl::HashOf(addr) % kShards;
+}
+
+GlobalSubchannelPool::GlobalSubchannelPool() = default;
+
+GlobalSubchannelPool::~GlobalSubchannelPool() = default;
+
 }  // namespace grpc_core

src/core/client_channel/global_subchannel_pool.h

@@ -32,10 +32,10 @@ namespace grpc_core {
 
 // The global subchannel pool. It shares subchannels among channels. There
 // should be only one instance of this class.
-class GlobalSubchannelPool final : public SubchannelPoolInterface {
+class LegacyGlobalSubchannelPool final : public SubchannelPoolInterface {
  public:
   // Gets the singleton instance.
-  static RefCountedPtr<GlobalSubchannelPool> instance();
+  static RefCountedPtr<LegacyGlobalSubchannelPool> instance();
 
   // Implements interface methods.
   RefCountedPtr<Subchannel> RegisterSubchannel(
@@ -48,8 +48,8 @@ class GlobalSubchannelPool final : public SubchannelPoolInterface {
       ABSL_LOCKS_EXCLUDED(mu_);
 
  private:
-  GlobalSubchannelPool() {}
-  ~GlobalSubchannelPool() override {}
+  LegacyGlobalSubchannelPool() {}
+  ~LegacyGlobalSubchannelPool() override {}
 
   // A map from subchannel key to subchannel.
   std::map<SubchannelKey, Subchannel*> subchannel_map_ ABSL_GUARDED_BY(mu_);
@@ -57,6 +57,39 @@ class GlobalSubchannelPool final : public SubchannelPoolInterface {
   Mutex mu_;
 };
 
+// The global subchannel pool. It shares subchannels among channels. There
+// should be only one instance of this class.
+class GlobalSubchannelPool final : public SubchannelPoolInterface {
+ public:
+  // Gets the singleton instance.
+  static RefCountedPtr<GlobalSubchannelPool> instance();
+
+  // Implements interface methods.
+  RefCountedPtr<Subchannel> RegisterSubchannel(
+      const SubchannelKey& key, RefCountedPtr<Subchannel> constructed) override;
+  void UnregisterSubchannel(const SubchannelKey& key,
+                            Subchannel* subchannel) override;
+  RefCountedPtr<Subchannel> FindSubchannel(const SubchannelKey& key) override;
+
+ private:
+  GlobalSubchannelPool();
+  ~GlobalSubchannelPool() override;
+
+  static const size_t kShards = 127;
+
+  using SubchannelMap = AVL<SubchannelKey, WeakRefCountedPtr<Subchannel>>;
+  struct LockedMap {
+    Mutex mu;
+    SubchannelMap map ABSL_GUARDED_BY(mu);
+  };
+  using ShardedMap = std::array<LockedMap, kShards>;
+
+  static size_t ShardIndex(const SubchannelKey& key);
+
+  ShardedMap write_shards_;
+  ShardedMap read_shards_;
+};
+
 }  // namespace grpc_core
 
 #endif  // GRPC_SRC_CORE_CLIENT_CHANNEL_GLOBAL_SUBCHANNEL_POOL_H

src/core/client_channel/subchannel.cc

@@ -452,10 +452,8 @@ void Subchannel::ConnectivityStateWatcherList::RemoveWatcherLocked(
 void Subchannel::ConnectivityStateWatcherList::NotifyLocked(
     grpc_connectivity_state state, const absl::Status& status) {
   for (const auto& watcher : watchers_) {
-    subchannel_->work_serializer_.Run([watcher = watcher->Ref(), state,
-                                       status]() mutable {
-      auto* watcher_ptr = watcher.get();
-      watcher_ptr->OnConnectivityStateChange(std::move(watcher), state, status);
+    subchannel_->work_serializer_.Run([watcher, state, status]() {
+      watcher->OnConnectivityStateChange(state, status);
     });
   }
 }
@@ -551,6 +549,8 @@ Subchannel::Subchannel(SubchannelKey key,
     channelz_node_->AddTraceEvent(
         channelz::ChannelTrace::Severity::Info,
         grpc_slice_from_static_string("subchannel created"));
+    channelz_node_->SetChannelArgs(args_);
+    args_ = args_.SetObject<channelz::BaseNode>(channelz_node_);
   }
 }
 
@@ -612,10 +612,8 @@ void Subchannel::WatchConnectivityState(
     grpc_pollset_set_add_pollset_set(pollset_set_, interested_parties);
   }
   work_serializer_.Run(
-      [watcher = watcher->Ref(), state = state_, status = status_]() mutable {
-        auto* watcher_ptr = watcher.get();
-        watcher_ptr->OnConnectivityStateChange(std::move(watcher), state,
-                                               status);
+      [watcher, state = state_, status = status_]() {
+        watcher->OnConnectivityStateChange(state, status);
       },
       DEBUG_LOCATION);
   watcher_list_.AddWatcherLocked(std::move(watcher));
@@ -792,7 +790,7 @@ void Subchannel::OnConnectingFinishedLocked(grpc_error_handle error) {
 }
 
 bool Subchannel::PublishTransportLocked() {
-  auto socket_node = std::move(connecting_result_.socket_node);
+  auto socket_node = connecting_result_.transport->GetSocketNode();
   if (connecting_result_.transport->filter_stack_transport() != nullptr) {
     // Construct channel stack.
     // Builder takes ownership of transport.

src/core/client_channel/subchannel.h

@@ -168,14 +168,8 @@ class Subchannel final : public DualRefCounted<Subchannel> {
     // Invoked whenever the subchannel's connectivity state changes.
     // There will be only one invocation of this method on a given watcher
     // instance at any given time.
-    // A ref to the watcher is passed in here so that the implementation
-    // can unref it in the appropriate synchronization context (e.g.,
-    // inside a WorkSerializer).
-    // TODO(roth): Figure out a cleaner way to guarantee that the ref is
-    // released in the right context.
-    virtual void OnConnectivityStateChange(
-        RefCountedPtr<ConnectivityStateWatcherInterface> self,
-        grpc_connectivity_state state, const absl::Status& status) = 0;
+    virtual void OnConnectivityStateChange(grpc_connectivity_state state,
+                                           const absl::Status& status) = 0;
 
     virtual grpc_pollset_set* interested_parties() = 0;
   };

src/core/client_channel/subchannel_pool_interface.cc

@@ -38,13 +38,12 @@ SubchannelKey::SubchannelKey(const grpc_resolved_address& address,
                              const ChannelArgs& args)
     : address_(address), args_(args) {}
 
-bool SubchannelKey::operator<(const SubchannelKey& other) const {
-  if (address_.len < other.address_.len) return true;
-  if (address_.len > other.address_.len) return false;
+int SubchannelKey::Compare(const SubchannelKey& other) const {
+  if (address_.len < other.address_.len) return -1;
+  if (address_.len > other.address_.len) return 1;
   int r = memcmp(address_.addr, other.address_.addr, address_.len);
-  if (r < 0) return true;
-  if (r > 0) return false;
-  return args_ < other.args();
+  if (r != 0) return r;
+  return QsortCompare(args_, other.args_);
 }
 
 std::string SubchannelKey::ToString() const {

src/core/client_channel/subchannel_pool_interface.h

@@ -45,7 +45,17 @@ class SubchannelKey final {
   SubchannelKey(SubchannelKey&& other) noexcept = default;
   SubchannelKey& operator=(SubchannelKey&& other) noexcept = default;
 
-  bool operator<(const SubchannelKey& other) const;
+  bool operator<(const SubchannelKey& other) const {
+    return Compare(other) < 0;
+  }
+  bool operator>(const SubchannelKey& other) const {
+    return Compare(other) > 0;
+  }
+  bool operator==(const SubchannelKey& other) const {
+    return Compare(other) == 0;
+  }
+
+  int Compare(const SubchannelKey& other) const;
 
   const grpc_resolved_address& address() const { return address_; }
   const ChannelArgs& args() const { return args_; }

src/core/config/config_vars.cc

@@ -76,6 +76,11 @@ ABSL_FLAG(absl::optional<bool>, grpc_cpp_experimental_disable_reflection, {},
           "EXPERIMENTAL. Only respected when there is a dependency on "
           ":grpc++_reflection. If true, no reflection server will be "
           "automatically added.");
+ABSL_FLAG(
+    absl::optional<int32_t>, grpc_channelz_max_orphaned_nodes, {},
+    "EXPERIMENTAL: If non-zero, extend the lifetime of channelz nodes past the "
+    "underlying object lifetime, up to this many nodes. The value may be "
+    "adjusted slightly to account for implementation limits.");
 
 namespace grpc_core {
 
@@ -84,6 +89,10 @@ ConfigVars::ConfigVars(const Overrides& overrides)
           LoadConfig(FLAGS_grpc_client_channel_backup_poll_interval_ms,
                      "GRPC_CLIENT_CHANNEL_BACKUP_POLL_INTERVAL_MS",
                      overrides.client_channel_backup_poll_interval_ms, 5000)),
+      channelz_max_orphaned_nodes_(
+          LoadConfig(FLAGS_grpc_channelz_max_orphaned_nodes,
+                     "GRPC_CHANNELZ_MAX_ORPHANED_NODES",
+                     overrides.channelz_max_orphaned_nodes, 0)),
       enable_fork_support_(LoadConfig(
           FLAGS_grpc_enable_fork_support, "GRPC_ENABLE_FORK_SUPPORT",
           overrides.enable_fork_support, GRPC_ENABLE_FORK_SUPPORT_DEFAULT)),
@@ -146,7 +155,8 @@ std::string ConfigVars::ToString() const {
       ", not_use_system_ssl_roots: ", NotUseSystemSslRoots() ? "true" : "false",
       ", ssl_cipher_suites: ", "\"", absl::CEscape(SslCipherSuites()), "\"",
       ", cpp_experimental_disable_reflection: ",
-      CppExperimentalDisableReflection() ? "true" : "false");
+      CppExperimentalDisableReflection() ? "true" : "false",
+      ", channelz_max_orphaned_nodes: ", ChannelzMaxOrphanedNodes());
 }
 
 }  // namespace grpc_core

src/core/config/config_vars.h

@@ -35,6 +35,7 @@ class GPR_DLL ConfigVars {
  public:
   struct Overrides {
     absl::optional<int32_t> client_channel_backup_poll_interval_ms;
+    absl::optional<int32_t> channelz_max_orphaned_nodes;
     absl::optional<bool> enable_fork_support;
     absl::optional<bool> abort_on_leaks;
     absl::optional<bool> not_use_system_ssl_roots;
@@ -104,12 +105,19 @@ class GPR_DLL ConfigVars {
   bool CppExperimentalDisableReflection() const {
     return cpp_experimental_disable_reflection_;
   }
+  // EXPERIMENTAL: If non-zero, extend the lifetime of channelz nodes past the
+  // underlying object lifetime, up to this many nodes. The value may be
+  // adjusted slightly to account for implementation limits.
+  int32_t ChannelzMaxOrphanedNodes() const {
+    return channelz_max_orphaned_nodes_;
+  }
 
  private:
   explicit ConfigVars(const Overrides& overrides);
   static const ConfigVars& Load();
   static std::atomic<ConfigVars*> config_vars_;
   int32_t client_channel_backup_poll_interval_ms_;
+  int32_t channelz_max_orphaned_nodes_;
   bool enable_fork_support_;
   bool abort_on_leaks_;
   bool not_use_system_ssl_roots_;

src/core/config/core_configuration.cc

@@ -25,8 +25,10 @@
 namespace grpc_core {
 
 std::atomic<CoreConfiguration*> CoreConfiguration::config_{nullptr};
-std::atomic<CoreConfiguration::RegisteredBuilder*> CoreConfiguration::builders_{
-    nullptr};
+std::atomic<CoreConfiguration::RegisteredBuilder*>
+    CoreConfiguration::builders_[static_cast<size_t>(BuilderScope::kCount)]{
+        nullptr, nullptr};
+std::atomic<bool> CoreConfiguration::has_config_ever_been_produced_{false};
 void (*CoreConfiguration::default_builder_)(CoreConfiguration::Builder*);
 
 CoreConfiguration::Builder::Builder() = default;
@@ -46,18 +48,31 @@ CoreConfiguration::CoreConfiguration(Builder* builder)
       lb_policy_registry_(builder->lb_policy_registry_.Build()),
       proxy_mapper_registry_(builder->proxy_mapper_registry_.Build()),
       certificate_provider_registry_(
-          builder->certificate_provider_registry_.Build()) {}
+          builder->certificate_provider_registry_.Build()),
+      endpoint_transport_registry_(
+          builder->endpoint_transport_registry_.Build()) {}
 
 void CoreConfiguration::RegisterBuilder(
-    absl::AnyInvocable<void(Builder*)> builder) {
+    BuilderScope scope, absl::AnyInvocable<void(Builder*)> builder,
+    SourceLocation whence) {
   CHECK(config_.load(std::memory_order_relaxed) == nullptr)
       << "CoreConfiguration was already instantiated before builder "
          "registration was completed";
+  if (scope == BuilderScope::kPersistent) {
+    CHECK(!has_config_ever_been_produced_.load(std::memory_order_relaxed))
+        << "Persistent builders cannot be registered after the first "
+           "CoreConfiguration has been produced";
+  }
+  CHECK_NE(scope, BuilderScope::kCount);
+  auto& head = builders_[static_cast<size_t>(scope)];
   RegisteredBuilder* n = new RegisteredBuilder();
+  VLOG(4) << "Registering " << scope << " builder from " << whence.file() << ":"
+          << whence.line();
   n->builder = std::move(builder);
-  n->next = builders_.load(std::memory_order_relaxed);
-  while (!builders_.compare_exchange_weak(n->next, n, std::memory_order_acq_rel,
-                                          std::memory_order_relaxed)) {
+  n->whence = whence;
+  n->next = head.load(std::memory_order_relaxed);
+  while (!head.compare_exchange_weak(n->next, n, std::memory_order_acq_rel,
+                                     std::memory_order_relaxed)) {
   }
   CHECK(config_.load(std::memory_order_relaxed) == nullptr)
       << "CoreConfiguration was already instantiated before builder "
@@ -65,6 +80,7 @@ void CoreConfiguration::RegisterBuilder(
 }
 
 const CoreConfiguration& CoreConfiguration::BuildNewAndMaybeSet() {
+  has_config_ever_been_produced_.store(true, std::memory_order_relaxed);
   // Construct builder, pass it up to code that knows about build configuration
   Builder builder;
   // The linked list of builders stores things in reverse registration order.
@@ -72,13 +88,21 @@ const CoreConfiguration& CoreConfiguration::BuildNewAndMaybeSet() {
   // actually need to run things in forward registration order, so we iterate
   // once over the linked list to build a vector of builders, and then iterate
   // over said vector in reverse to actually run the builders.
+  // Note that we also iterate scopes in reverse order here too, so that when
+  // we run the builders in the reverse generated order we'll actually run
+  // persistent builders before ephemeral ones.
   std::vector<RegisteredBuilder*> registered_builders;
-  for (RegisteredBuilder* b = builders_.load(std::memory_order_acquire);
-       b != nullptr; b = b->next) {
-    registered_builders.push_back(b);
+  for (auto scope : {BuilderScope::kEphemeral, BuilderScope::kPersistent}) {
+    for (RegisteredBuilder* b = builders_[static_cast<size_t>(scope)].load(
+             std::memory_order_acquire);
+         b != nullptr; b = b->next) {
+      registered_builders.push_back(b);
+    }
   }
   for (auto it = registered_builders.rbegin(); it != registered_builders.rend();
        ++it) {
+    VLOG(4) << "Running builder from " << (*it)->whence.file() << ":"
+            << (*it)->whence.line();
     (*it)->builder(&builder);
   }
   // Finally, call the built in configuration builder.
@@ -100,7 +124,8 @@ const CoreConfiguration& CoreConfiguration::BuildNewAndMaybeSet() {
 void CoreConfiguration::Reset() {
   delete config_.exchange(nullptr, std::memory_order_acquire);
   RegisteredBuilder* builder =
-      builders_.exchange(nullptr, std::memory_order_acquire);
+      builders_[static_cast<size_t>(BuilderScope::kEphemeral)].exchange(
+          nullptr, std::memory_order_acquire);
   while (builder != nullptr) {
     RegisteredBuilder* next = builder->next;
     delete builder;
@@ -108,4 +133,18 @@ void CoreConfiguration::Reset() {
   }
 }
 
+void CoreConfiguration::
+    ResetEverythingIncludingPersistentBuildersAbsolutelyNotRecommended() {
+  has_config_ever_been_produced_.store(false, std::memory_order_relaxed);
+  RegisteredBuilder* builder =
+      builders_[static_cast<size_t>(BuilderScope::kPersistent)].exchange(
+          nullptr, std::memory_order_acquire);
+  while (builder != nullptr) {
+    RegisteredBuilder* next = builder->next;
+    delete builder;
+    builder = next;
+  }
+  Reset();
+}
+
 }  // namespace grpc_core

src/core/config/core_configuration.h

@@ -16,6 +16,7 @@
 #define GRPC_SRC_CORE_CONFIG_CORE_CONFIGURATION_H
 
 #include <grpc/support/port_platform.h>
+#include <sys/stat.h>
 
 #include <atomic>
 
@@ -30,6 +31,8 @@
 #include "src/core/load_balancing/lb_policy_registry.h"
 #include "src/core/resolver/resolver_registry.h"
 #include "src/core/service_config/service_config_parser.h"
+#include "src/core/transport/endpoint_transport.h"
+#include "src/core/util/debug_location.h"
 
 namespace grpc_core {
 
@@ -40,6 +43,27 @@ class GRPC_DLL CoreConfiguration {
   CoreConfiguration(const CoreConfiguration&) = delete;
   CoreConfiguration& operator=(const CoreConfiguration&) = delete;
 
+  // BulderScope is used to indicate whether a builder is persistent - these
+  // are builders that are used every time the configuration is built, or
+  // ephemeral - each time the configuration is built these are thrown away.
+  //
+  // Considerations for choosing persistent vs ephemeral:
+  // - For testing we want ephemeral builders, so the next test can throw away
+  //   configuration.
+  // - For adapting gRPC to different environments we typically want persistent
+  //   builders.
+  //   - However, if the adaption should run only once per process, then
+  //     ephemeral is better.
+  //
+  // Builders are instantiated in scope order - persistent first, ephemeral
+  // second.
+  enum class BuilderScope {
+    kPersistent,
+    kEphemeral,
+    // Must be last, do not use as a scope.
+    kCount,
+  };
+
   // Builder is passed to plugins, etc... at initialization time to collect
   // their configuration and assemble the published CoreConfiguration.
   class Builder {
@@ -78,6 +102,10 @@ class GRPC_DLL CoreConfiguration {
       return &certificate_provider_registry_;
     }
 
+    EndpointTransportRegistry::Builder* endpoint_transport_registry() {
+      return &endpoint_transport_registry_;
+    }
+
    private:
     friend class CoreConfiguration;
 
@@ -90,6 +118,7 @@ class GRPC_DLL CoreConfiguration {
     LoadBalancingPolicyRegistry::Builder lb_policy_registry_;
     ProxyMapperRegistry::Builder proxy_mapper_registry_;
     CertificateProviderRegistry::Builder certificate_provider_registry_;
+    EndpointTransportRegistry::Builder endpoint_transport_registry_;
 
     Builder();
     CoreConfiguration* Build();
@@ -99,6 +128,7 @@ class GRPC_DLL CoreConfiguration {
   struct RegisteredBuilder {
     absl::AnyInvocable<void(Builder*)> builder;
     RegisteredBuilder* next;
+    SourceLocation whence;
   };
 
   // Temporarily replaces core configuration with what is built from the
@@ -121,8 +151,10 @@ class GRPC_DLL CoreConfiguration {
       // Backup current core configuration and replace/reset.
       config_restore_ =
           CoreConfiguration::config_.exchange(p, std::memory_order_acquire);
-      builders_restore_ = CoreConfiguration::builders_.exchange(
-          nullptr, std::memory_order_acquire);
+      builders_restore_ =
+          CoreConfiguration::builders_[static_cast<size_t>(
+                                           BuilderScope::kEphemeral)]
+              .exchange(nullptr, std::memory_order_acquire);
     }
 
     ~WithSubstituteBuilder() {
@@ -130,8 +162,10 @@ class GRPC_DLL CoreConfiguration {
       Reset();
       CHECK(CoreConfiguration::config_.exchange(
                 config_restore_, std::memory_order_acquire) == nullptr);
-      CHECK(CoreConfiguration::builders_.exchange(
-                builders_restore_, std::memory_order_acquire) == nullptr);
+      CHECK(CoreConfiguration::builders_[static_cast<size_t>(
+                                             BuilderScope::kEphemeral)]
+                .exchange(builders_restore_, std::memory_order_acquire) ==
+            nullptr);
     }
 
    private:
@@ -153,13 +187,34 @@ class GRPC_DLL CoreConfiguration {
   // Attach a registration function globally.
   // Each registration function is called *in addition to*
   // BuildCoreConfiguration for the default core configuration.
-  static void RegisterBuilder(absl::AnyInvocable<void(Builder*)> builder);
+  static void RegisterBuilder(BuilderScope scope,
+                              absl::AnyInvocable<void(Builder*)> builder,
+                              SourceLocation whence);
+
+  static void RegisterPersistentBuilder(
+      absl::AnyInvocable<void(Builder*)> builder, SourceLocation whence = {}) {
+    RegisterBuilder(BuilderScope::kPersistent, std::move(builder), whence);
+  }
+
+  static void RegisterEphemeralBuilder(
+      absl::AnyInvocable<void(Builder*)> builder, SourceLocation whence = {}) {
+    RegisterBuilder(BuilderScope::kEphemeral, std::move(builder), whence);
+  }
 
   // Drop the core configuration. Users must ensure no other threads are
   // accessing the configuration.
-  // Clears any dynamically registered builders.
+  // Clears any dynamically registered ephemeral builders.
   static void Reset();
 
+  // Reset, but also reset persistent builders. This is not recommended, but
+  // is useful for tests that assume exactly the default open source
+  // configuration when running in other environments.
+  //
+  // TODO(ctiller, roth, yashkt): Remove the need for this method, and then
+  // move the legacy plugin registration mechanism to be a persistent builder.
+  static void
+  ResetEverythingIncludingPersistentBuildersAbsolutelyNotRecommended();
+
   // Helper for tests: Reset the configuration, build a special one, run some
   // code, and then reset the configuration again.
   // Templatized to be sure no codegen in normal builds.
@@ -206,6 +261,10 @@ class GRPC_DLL CoreConfiguration {
     return certificate_provider_registry_;
   }
 
+  const EndpointTransportRegistry& endpoint_transport_registry() const {
+    return endpoint_transport_registry_;
+  }
+
   static void SetDefaultBuilder(void (*builder)(CoreConfiguration::Builder*)) {
     default_builder_ = builder;
   }
@@ -219,8 +278,13 @@ class GRPC_DLL CoreConfiguration {
 
   // The configuration
   static std::atomic<CoreConfiguration*> config_;
+  // Has a configuration *ever* been produced - we verify this is false for
+  // persistent builders so that we can prove consistency build to build for
+  // these.
+  static std::atomic<bool> has_config_ever_been_produced_;
   // Extra registered builders
-  static std::atomic<RegisteredBuilder*> builders_;
+  static std::atomic<RegisteredBuilder*>
+      builders_[static_cast<size_t>(BuilderScope::kCount)];
   // Default builder
   static void (*default_builder_)(CoreConfiguration::Builder*);
 
@@ -233,8 +297,26 @@ class GRPC_DLL CoreConfiguration {
   LoadBalancingPolicyRegistry lb_policy_registry_;
   ProxyMapperRegistry proxy_mapper_registry_;
   CertificateProviderRegistry certificate_provider_registry_;
+  EndpointTransportRegistry endpoint_transport_registry_;
 };
 
+template <typename Sink>
+void AbslStringify(Sink& sink, CoreConfiguration::BuilderScope scope) {
+  switch (scope) {
+    case CoreConfiguration::BuilderScope::kPersistent:
+      sink.Append("Persistent");
+      break;
+    case CoreConfiguration::BuilderScope::kEphemeral:
+      sink.Append("Ephemeral");
+      break;
+    case CoreConfiguration::BuilderScope::kCount:
+      sink.Append("Count(");
+      sink.Append(std::to_string(static_cast<size_t>(scope)));
+      sink.Append(")");
+      break;
+  }
+}
+
 extern void BuildCoreConfiguration(CoreConfiguration::Builder* builder);
 
 }  // namespace grpc_core

src/core/credentials/call/external/aws_request_signer.cc

@@ -151,8 +151,9 @@ std::map<std::string, std::string> AwsRequestSigner::GetSignedRequestHeaders() {
   canonical_request_vector.emplace_back(query);
   canonical_request_vector.emplace_back("\n");
   // 4. CanonicalHeaders
+  std::string authority = url_.authority();
   if (request_headers_.empty()) {
-    request_headers_.insert({"host", url_.authority()});
+    request_headers_.insert({"host", authority});
     if (!token_.empty()) {
       request_headers_.insert({"x-amz-security-token", token_});
     }
@@ -198,7 +199,7 @@ std::map<std::string, std::string> AwsRequestSigner::GetSignedRequestHeaders() {
   string_to_sign_vector.emplace_back("\n");
   // 3. CredentialScope
   std::pair<absl::string_view, absl::string_view> host_parts =
-      absl::StrSplit(url_.authority(), absl::MaxSplits('.', 1));
+      absl::StrSplit(authority, absl::MaxSplits('.', 1));
   std::string service_name(host_parts.first);
   std::string credential_scope = absl::StrFormat(
       "%s/%s/%s/aws4_request", request_date_short, region_, service_name);

src/core/credentials/call/external/url_external_account_credentials.cc

@@ -146,8 +146,8 @@ UrlExternalAccountCredentials::RetrieveSubjectToken(
     Timestamp deadline,
     absl::AnyInvocable<void(absl::StatusOr<std::string>)> on_done) {
   auto url_for_request =
-      URI::Create(url_.scheme(), url_.authority(), url_full_path_,
-                  {} /* query params */, "" /* fragment */);
+      URI::Create(url_.scheme(), url_.user_info(), url_.host_port(),
+                  url_full_path_, {} /* query params */, "" /* fragment */);
   if (!url_for_request.ok()) {
     return MakeOrphanable<NoOpFetchBody>(
         event_engine(), std::move(on_done),

src/core/credentials/call/gcp_service_account_identity/gcp_service_account_identity_credentials.cc

@@ -180,7 +180,7 @@ GcpServiceAccountIdentityCallCredentials::StartHttpRequest(
   // channel. This would allow us to cancel an authentication query when under
   // extreme memory pressure.
   auto uri = URI::Create(
-      "http", "metadata.google.internal.",
+      "http", /*user_info=*/"", "metadata.google.internal.",
       "/computeMetadata/v1/instance/service-accounts/default/identity",
       {{"audience", audience_}}, /*fragment=*/"");
   CHECK_OK(uri);  // params are hardcoded

src/core/credentials/call/jwt/jwt_verifier.cc

@@ -756,8 +756,8 @@ static void on_openid_config_retrieved(void* user_data,
   // TODO(ctiller): Carry the resource_quota in ctx and share it with the host
   // channel. This would allow us to cancel an authentication query when under
   // extreme memory pressure.
-  uri = grpc_core::URI::Create("https", host, path, {} /* query params /*/,
-                               "" /* fragment */);
+  uri = grpc_core::URI::Create("https", /*user_info=*/"", host, path,
+                               {} /* query params /*/, "" /* fragment */);
   if (!uri.ok()) {
     goto error;
   }
@@ -886,8 +886,8 @@ static void retrieve_key_and_verify(verifier_cb_ctx* ctx) {
   // TODO(ctiller): Carry the resource_quota in ctx and share it with the host
   // channel. This would allow us to cancel an authentication query when under
   // extreme memory pressure.
-  uri = grpc_core::URI::Create("https", host, path, {} /* query params */,
-                               "" /* fragment */);
+  uri = grpc_core::URI::Create("https", /*user_info=*/"", host, path,
+                               {} /* query params */, "" /* fragment */);
   if (!uri.ok()) {
     goto error;
   }

src/core/credentials/call/oauth2/oauth2_credentials.cc

@@ -314,7 +314,8 @@ class grpc_compute_engine_token_fetcher_credentials
     // TODO(ctiller): Carry the memory quota in ctx and share it with the host
     // channel. This would allow us to cancel an authentication query when under
     // extreme memory pressure.
-    auto uri = grpc_core::URI::Create("http", GRPC_COMPUTE_ENGINE_METADATA_HOST,
+    auto uri = grpc_core::URI::Create("http", /*user_info=*/"",
+                                      GRPC_COMPUTE_ENGINE_METADATA_HOST,
                                       GRPC_COMPUTE_ENGINE_METADATA_TOKEN_PATH,
                                       {} /* query params */, "" /* fragment */);
     CHECK(uri.ok());  // params are hardcoded
@@ -372,7 +373,8 @@ grpc_google_refresh_token_credentials::StartHttpRequest(
   // TODO(ctiller): Carry the memory quota in ctx and share it with the host
   // channel. This would allow us to cancel an authentication query when under
   // extreme memory pressure.
-  auto uri = grpc_core::URI::Create("https", GRPC_GOOGLE_OAUTH2_SERVICE_HOST,
+  auto uri = grpc_core::URI::Create("https", /*user_info=*/"",
+                                    GRPC_GOOGLE_OAUTH2_SERVICE_HOST,
                                     GRPC_GOOGLE_OAUTH2_SERVICE_TOKEN_PATH,
                                     {} /* query params */, "" /* fragment */);
   CHECK(uri.ok());  // params are hardcoded

src/core/credentials/transport/alts/alts_security_connector.cc

@@ -102,10 +102,11 @@ class grpc_alts_channel_security_connector final
         static_cast<const grpc_alts_credentials*>(channel_creds());
     const size_t user_specified_max_frame_size =
         std::max(0, args.GetInt(GRPC_ARG_TSI_MAX_FRAME_SIZE).value_or(0));
-    CHECK(alts_tsi_handshaker_create(creds->options(), target_name_,
-                                     creds->handshaker_service_url(), true,
-                                     interested_parties, &handshaker,
-                                     user_specified_max_frame_size) == TSI_OK);
+    CHECK(alts_tsi_handshaker_create(
+              creds->options(), target_name_, creds->handshaker_service_url(),
+              true, interested_parties, &handshaker,
+              user_specified_max_frame_size,
+              args.GetOwnedString(GRPC_ARG_TRANSPORT_PROTOCOLS)) == TSI_OK);
     handshake_manager->Add(
         grpc_core::SecurityHandshakerCreate(handshaker, this, args));
   }
@@ -155,10 +156,10 @@ class grpc_alts_server_security_connector final
         static_cast<const grpc_alts_server_credentials*>(server_creds());
     size_t user_specified_max_frame_size =
         std::max(0, args.GetInt(GRPC_ARG_TSI_MAX_FRAME_SIZE).value_or(0));
-    CHECK(alts_tsi_handshaker_create(creds->options(), nullptr,
-                                     creds->handshaker_service_url(), false,
-                                     interested_parties, &handshaker,
-                                     user_specified_max_frame_size) == TSI_OK);
+    CHECK(alts_tsi_handshaker_create(
+              creds->options(), nullptr, creds->handshaker_service_url(), false,
+              interested_parties, &handshaker, user_specified_max_frame_size,
+              args.GetOwnedString(GRPC_ARG_TRANSPORT_PROTOCOLS)) == TSI_OK);
     handshake_manager->Add(
         grpc_core::SecurityHandshakerCreate(handshaker, this, args));
   }

src/core/credentials/transport/google_default/google_default_credentials.cc

@@ -217,9 +217,9 @@ static int is_metadata_server_reachable() {
   detector.is_done = 0;
   detector.success = 0;
   memset(&request, 0, sizeof(grpc_http_request));
-  auto uri =
-      grpc_core::URI::Create("http", GRPC_COMPUTE_ENGINE_DETECTION_HOST, "/",
-                             {} /* query params */, "" /* fragment */);
+  auto uri = grpc_core::URI::Create("http", /*user_info=*/"",
+                                    GRPC_COMPUTE_ENGINE_DETECTION_HOST, "/",
+                                    {} /* query params */, "" /* fragment */);
   CHECK(uri.ok());  // params are hardcoded
   auto http_request = grpc_core::HttpRequest::Get(
       std::move(*uri), nullptr /* channel args */, &detector.pollent, &request,

src/core/credentials/transport/ssl/ssl_credentials.cc

@@ -278,8 +278,8 @@ grpc_ssl_server_credentials::~grpc_ssl_server_credentials() {
 }
 grpc_core::RefCountedPtr<grpc_server_security_connector>
 grpc_ssl_server_credentials::create_security_connector(
-    const grpc_core::ChannelArgs& /* args */) {
-  return grpc_ssl_server_security_connector_create(this->Ref());
+    const grpc_core::ChannelArgs& args) {
+  return grpc_ssl_server_security_connector_create(this->Ref(), args);
 }
 
 grpc_core::UniqueTypeName grpc_ssl_server_credentials::Type() {

src/core/credentials/transport/ssl/ssl_security_connector.cc

@@ -108,7 +108,8 @@ class grpc_ssl_channel_security_connector final
         overridden_target_name_.empty() ? target_name_.c_str()
                                         : overridden_target_name_.c_str(),
         /*network_bio_buf_size=*/0,
-        /*ssl_bio_buf_size=*/0, &tsi_hs);
+        /*ssl_bio_buf_size=*/0,
+        args.GetOwnedString(GRPC_ARG_TRANSPORT_PROTOCOLS), &tsi_hs);
     if (result != TSI_OK) {
       LOG(ERROR) << "Handshaker creation failed with error "
                  << tsi_result_to_string(result);
@@ -198,7 +199,24 @@ class grpc_ssl_server_security_connector
     return server_handshaker_factory_;
   }
 
-  grpc_security_status InitializeHandshakerFactory() {
+  // Helper method to initialize the handshaker factory for all handshaker on
+  // the server side.
+  // - alpn_preferred_protocol_raw_list: an optional string that represents the
+  // comma-separated ordered list of preferred protocols for alpn negotiation on
+  // this server.
+  //
+  // For the server handshaker, override the preferred protocols given
+  // by the channel args on the handshaker factory creation. Do this for all
+  // handshake that a server may produce because it is unlikely that a server
+  // handshaker would change protocol list per handshake.
+  //
+  // OpenSSL's provided method to override the selection of the handshaker
+  // protocols for alpn is only available per context base which makes it
+  // thread-unsafe. The introduction of a lock in the server callback may make
+  // the alternative thread-safe, however it will introduce too much contention
+  // which in turn will affect performance.
+  grpc_security_status InitializeHandshakerFactory(
+      std::optional<std::string> alpn_preferred_protocol_raw_list) {
     if (has_cert_config_fetcher()) {
       // Load initial credentials from certificate_config_fetcher:
       if (!try_fetch_ssl_server_credentials()) {
@@ -209,8 +227,17 @@ class grpc_ssl_server_security_connector
       auto* server_credentials =
           static_cast<const grpc_ssl_server_credentials*>(server_creds());
       size_t num_alpn_protocols = 0;
-      const char** alpn_protocol_strings =
-          grpc_fill_alpn_protocol_strings(&num_alpn_protocols);
+      const char** alpn_protocol_strings = nullptr;
+      if (alpn_preferred_protocol_raw_list.has_value()) {
+#if TSI_OPENSSL_ALPN_SUPPORT
+        alpn_protocol_strings = ParseAlpnStringIntoArray(
+            alpn_preferred_protocol_raw_list.value(), &num_alpn_protocols);
+#endif  // TSI_OPENSSL_ALPN_SUPPORT
+      }
+      if (alpn_protocol_strings == nullptr) {
+        alpn_protocol_strings =
+            grpc_fill_alpn_protocol_strings(&num_alpn_protocols);
+      }
       tsi_ssl_server_handshaker_options options;
       options.pem_key_cert_pairs =
           server_credentials->config().pem_key_cert_pairs;
@@ -277,9 +304,10 @@ class grpc_ssl_server_security_connector
   }
 
  private:
-  // Attempts to fetch the server certificate config if a callback is available.
-  // Current certificate config will continue to be used if the callback returns
-  // an error. Returns true if new credentials were successfully loaded.
+  // Attempts to fetch the server certificate config if a callback is
+  // available. Current certificate config will continue to be used if the
+  // callback returns an error. Returns true if new credentials were
+  // successfully loaded.
   bool try_fetch_ssl_server_credentials() {
     grpc_ssl_server_certificate_config* certificate_config = nullptr;
     bool status;
@@ -307,8 +335,8 @@ class grpc_ssl_server_security_connector
     return status;
   }
 
-  // Attempts to replace the server_handshaker_factory with a new factory using
-  // the provided grpc_ssl_server_certificate_config. Should new factory
+  // Attempts to replace the server_handshaker_factory with a new factory
+  // using the provided grpc_ssl_server_certificate_config. Should new factory
   // creation fail, the existing factory will not be replaced. Returns true on
   // success (new factory created).
   bool try_replace_server_handshaker_factory(
@@ -390,12 +418,14 @@ grpc_ssl_channel_security_connector_create(
 
 grpc_core::RefCountedPtr<grpc_server_security_connector>
 grpc_ssl_server_security_connector_create(
-    grpc_core::RefCountedPtr<grpc_server_credentials> server_credentials) {
+    grpc_core::RefCountedPtr<grpc_server_credentials> server_credentials,
+    const grpc_core::ChannelArgs& args) {
   CHECK(server_credentials != nullptr);
   grpc_core::RefCountedPtr<grpc_ssl_server_security_connector> c =
       grpc_core::MakeRefCounted<grpc_ssl_server_security_connector>(
           std::move(server_credentials));
-  const grpc_security_status retval = c->InitializeHandshakerFactory();
+  const grpc_security_status retval = c->InitializeHandshakerFactory(
+      args.GetOwnedString(GRPC_ARG_TRANSPORT_PROTOCOLS));
   if (retval != GRPC_SECURITY_OK) {
     return nullptr;
   }

src/core/credentials/transport/ssl/ssl_security_connector.h

@@ -76,6 +76,7 @@ struct grpc_ssl_server_config {
 //
 grpc_core::RefCountedPtr<grpc_server_security_connector>
 grpc_ssl_server_security_connector_create(
-    grpc_core::RefCountedPtr<grpc_server_credentials> server_credentials);
+    grpc_core::RefCountedPtr<grpc_server_credentials> server_credentials,
+    const grpc_core::ChannelArgs& args);
 
 #endif  // GRPC_SRC_CORE_CREDENTIALS_TRANSPORT_SSL_SSL_SECURITY_CONNECTOR_H

src/core/credentials/transport/tls/ssl_utils.cc

@@ -200,6 +200,24 @@ const char** grpc_fill_alpn_protocol_strings(size_t* num_alpn_protocols) {
   return alpn_protocol_strings;
 }
 
+const char** ParseAlpnStringIntoArray(absl::string_view preferred_protocols_raw,
+                                      size_t* num_alpn_protocols) {
+  CHECK_NE(num_alpn_protocols, nullptr);
+  std::vector<std::string> preferred_protocols;
+  preferred_protocols =
+      absl::StrSplit(preferred_protocols_raw, ',', absl::SkipWhitespace());
+  *num_alpn_protocols = preferred_protocols.size();
+  const char** alpn_protocol_strings = nullptr;
+  if (*num_alpn_protocols != 0) {
+    alpn_protocol_strings = static_cast<const char**>(
+        gpr_malloc(sizeof(const char*) * (*num_alpn_protocols)));
+    for (size_t i = 0; i < *num_alpn_protocols; i++) {
+      alpn_protocol_strings[i] = gpr_strdup(preferred_protocols[i].c_str());
+    }
+  }
+  return alpn_protocol_strings;
+}
+
 int grpc_ssl_host_matches_name(const tsi_peer* peer,
                                absl::string_view peer_name) {
   absl::string_view allocated_name;

src/core/credentials/transport/tls/ssl_utils.h

@@ -77,6 +77,11 @@ tsi_tls_version grpc_get_tsi_tls_version(grpc_tls_version tls_version);
 // Return an array of strings containing alpn protocols.
 const char** grpc_fill_alpn_protocol_strings(size_t* num_alpn_protocols);
 
+// Parse a list of comma-separated protocol names into a const char** struct
+// that can be injected into the handshaker factory options.
+const char** ParseAlpnStringIntoArray(absl::string_view preferred_protocols,
+                                      size_t* num_alpn_protocols);
+
 // Initialize TSI SSL server/client handshaker factory.
 grpc_security_status grpc_ssl_tsi_client_handshaker_factory_init(
     tsi_ssl_pem_key_cert_pair* key_cert_pair, const char* pem_root_certs,

src/core/credentials/transport/tls/tls_security_connector.cc

@@ -347,7 +347,8 @@ void TlsChannelSecurityConnector::add_handshakers(
         overridden_target_name_.empty() ? target_name_.c_str()
                                         : overridden_target_name_.c_str(),
         /*network_bio_buf_size=*/0,
-        /*ssl_bio_buf_size=*/0, &tsi_hs);
+        /*ssl_bio_buf_size=*/0,
+        args.GetOwnedString(GRPC_ARG_TRANSPORT_PROTOCOLS), &tsi_hs);
     if (result != TSI_OK) {
       LOG(ERROR) << "Handshaker creation failed with error "
                  << tsi_result_to_string(result);

src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc

@@ -50,6 +50,7 @@
 #include "src/core/util/no_destruct.h"
 #include "src/core/util/orphanable.h"
 #include "src/core/util/per_cpu.h"
+#include "src/core/util/shared_bit_gen.h"
 #include "src/core/util/status_helper.h"
 #include "src/core/util/sync.h"
 
@@ -107,9 +108,11 @@ struct LegacyMaxAgeFilter::Config {
         return absl::Uniform(bit_gen, min, max);
       }
     };
-    static NoDestruct<PerCpu<BitGen>> bit_gen(PerCpuOptions().SetMaxShards(8));
-    const double multiplier = bit_gen->this_cpu().MakeUniformDouble(
-        1.0 - kMaxConnectionAgeJitter, 1.0 + kMaxConnectionAgeJitter);
+    const double multiplier = []() {
+      SharedBitGen g;
+      return absl::Uniform(g, 1.0 - kMaxConnectionAgeJitter,
+                           1.0 + kMaxConnectionAgeJitter);
+    }();
     // GRPC_MILLIS_INF_FUTURE - 0.5 converts the value to float, so that result
     // will not be cast to int implicitly before the comparison.
     return Config{args_max_age * multiplier, args_max_idle * multiplier,

src/core/ext/filters/http/message_compress/compression_filter.h

@@ -91,6 +91,20 @@ class ChannelCompression {
       bool is_client, MessageHandle message, DecompressArgs args,
       CallTracerInterface* call_tracer) const;
 
+  Json::Object ToJsonObject() const {
+    Json::Object object;
+    if (max_recv_size_.has_value()) {
+      object["maxRecvSize"] = Json::FromNumber(*max_recv_size_);
+    }
+    object["defaultCompressionAlgorithm"] = Json::FromString(
+        CompressionAlgorithmAsString(default_compression_algorithm_));
+    object["enabledCompressionAlgorithms"] = Json::FromString(
+        std::string(enabled_compression_algorithms_.ToString()));
+    object["enableCompression"] = Json::FromBool(enable_compression_);
+    object["enableDecompression"] = Json::FromBool(enable_decompression_);
+    return object;
+  }
+
  private:
   // Max receive message length, if set.
   std::optional<uint32_t> max_recv_size_;
@@ -106,7 +120,8 @@ class ChannelCompression {
 };
 
 class ClientCompressionFilter final
-    : public ImplementChannelFilter<ClientCompressionFilter> {
+    : public ImplementChannelFilter<ClientCompressionFilter>,
+      public channelz::DataSource {
  public:
   static const grpc_channel_filter kFilter;
 
@@ -116,7 +131,14 @@ class ClientCompressionFilter final
       const ChannelArgs& args, ChannelFilter::Args filter_args);
 
   explicit ClientCompressionFilter(const ChannelArgs& args)
-      : compression_engine_(args) {}
+      : channelz::DataSource(args.GetObjectRef<channelz::BaseNode>()),
+        compression_engine_(args) {}
+  ~ClientCompressionFilter() override { ResetDataSource(); }
+
+  void AddData(channelz::DataSink& sink) override {
+    sink.AddAdditionalInfo("clientCompressionFilter",
+                           compression_engine_.ToJsonObject());
+  }
 
   // Construct a promise for one call.
   class Call {
@@ -148,7 +170,8 @@ class ClientCompressionFilter final
 };
 
 class ServerCompressionFilter final
-    : public ImplementChannelFilter<ServerCompressionFilter> {
+    : public ImplementChannelFilter<ServerCompressionFilter>,
+      public channelz::DataSource {
  public:
   static const grpc_channel_filter kFilter;
 
@@ -158,7 +181,14 @@ class ServerCompressionFilter final
       const ChannelArgs& args, ChannelFilter::Args filter_args);
 
   explicit ServerCompressionFilter(const ChannelArgs& args)
-      : compression_engine_(args) {}
+      : channelz::DataSource(args.GetObjectRef<channelz::BaseNode>()),
+        compression_engine_(args) {}
+  ~ServerCompressionFilter() override { ResetDataSource(); }
+
+  void AddData(channelz::DataSink& sink) override {
+    sink.AddAdditionalInfo("serverCompressionFilter",
+                           compression_engine_.ToJsonObject());
+  }
 
   // Construct a promise for one call.
   class Call {

src/core/ext/filters/http/server/http_server_filter.cc

@@ -153,7 +153,7 @@ void HttpServerFilter::Call::OnServerTrailingMetadata(ServerMetadata& md) {
 absl::StatusOr<std::unique_ptr<HttpServerFilter>> HttpServerFilter::Create(
     const ChannelArgs& args, ChannelFilter::Args) {
   return std::make_unique<HttpServerFilter>(
-      args.GetBool(GRPC_ARG_SURFACE_USER_AGENT).value_or(true),
+      args, args.GetBool(GRPC_ARG_SURFACE_USER_AGENT).value_or(true),
       args.GetBool(
               GRPC_ARG_DO_NOT_USE_UNLESS_YOU_HAVE_PERMISSION_FROM_GRPC_TEAM_ALLOW_BROKEN_PUT_REQUESTS)
           .value_or(false));

src/core/ext/filters/http/server/http_server_filter.h

@@ -31,7 +31,8 @@
 namespace grpc_core {
 
 // Processes metadata on the server side for HTTP2 transports
-class HttpServerFilter : public ImplementChannelFilter<HttpServerFilter> {
+class HttpServerFilter : public ImplementChannelFilter<HttpServerFilter>,
+                         public channelz::DataSource {
  public:
   static const grpc_channel_filter kFilter;
 
@@ -40,9 +41,19 @@ class HttpServerFilter : public ImplementChannelFilter<HttpServerFilter> {
   static absl::StatusOr<std::unique_ptr<HttpServerFilter>> Create(
       const ChannelArgs& args, ChannelFilter::Args filter_args);
 
-  HttpServerFilter(bool surface_user_agent, bool allow_put_requests)
-      : surface_user_agent_(surface_user_agent),
+  HttpServerFilter(const ChannelArgs& args, bool surface_user_agent,
+                   bool allow_put_requests)
+      : channelz::DataSource(args.GetObjectRef<channelz::BaseNode>()),
+        surface_user_agent_(surface_user_agent),
         allow_put_requests_(allow_put_requests) {}
+  ~HttpServerFilter() override { ResetDataSource(); }
+
+  void AddData(channelz::DataSink& sink) override {
+    Json::Object object;
+    object["surfaceUserAgent"] = Json::FromBool(surface_user_agent_);
+    object["allowPutRequests"] = Json::FromBool(allow_put_requests_);
+    sink.AddAdditionalInfo("httpServerFilter", object);
+  }
 
   class Call {
    public:

src/core/ext/transport/chttp2/chttp2_plugin.cc

@@ -0,0 +1,40 @@
+// Copyright 2025 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "src/core/config/core_configuration.h"
+#include "src/core/ext/transport/chttp2/client/chttp2_connector.h"
+#include "src/core/ext/transport/chttp2/server/chttp2_server.h"
+#include "src/core/transport/endpoint_transport.h"
+
+namespace grpc_core {
+namespace {
+class Chttp2Transport final : public EndpointTransport {
+ public:
+  absl::StatusOr<grpc_channel*> ChannelCreate(
+      std::string target, const ChannelArgs& args) override {
+    return CreateHttp2Channel(target, args);
+  }
+
+  absl::StatusOr<int> AddPort(Server* server, std::string addr,
+                              const ChannelArgs& args) override {
+    return Chttp2ServerAddPort(server, addr.c_str(), args);
+  }
+};
+}  // namespace
+
+void RegisterChttp2Transport(CoreConfiguration::Builder* builder) {
+  builder->endpoint_transport_registry()->RegisterTransport(
+      "h2", std::make_unique<Chttp2Transport>());
+}
+}  // namespace grpc_core

src/core/ext/transport/chttp2/client/chttp2_connector.cc

@@ -64,6 +64,7 @@
 #include "src/core/lib/transport/error_utils.h"
 #include "src/core/lib/transport/transport.h"
 #include "src/core/resolver/resolver_registry.h"
+#include "src/core/transport/endpoint_transport_client_channel_factory.h"
 #include "src/core/util/debug_location.h"
 #include "src/core/util/orphanable.h"
 #include "src/core/util/status_helper.h"
@@ -145,8 +146,6 @@ void Chttp2Connector::OnHandshakeDone(absl::StatusOr<HandshakerArgs*> result) {
     result_->transport = grpc_create_chttp2_transport(
         (*result)->args, std::move((*result)->endpoint), true);
     CHECK_NE(result_->transport, nullptr);
-    result_->socket_node =
-        grpc_chttp2_transport_get_socket_node(result_->transport);
     result_->channel_args = std::move((*result)->args);
     Ref().release();  // Ref held by OnReceiveSettings()
     GRPC_CLOSURE_INIT(&on_receive_settings_, OnReceiveSettings, this,
@@ -225,121 +224,21 @@ void Chttp2Connector::MaybeNotify(grpc_error_handle error) {
   }
 }
 
-namespace {
-
-class Chttp2SecureClientChannelFactory : public ClientChannelFactory {
- public:
-  RefCountedPtr<Subchannel> CreateSubchannel(
-      const grpc_resolved_address& address, const ChannelArgs& args) override {
-    absl::StatusOr<ChannelArgs> new_args = GetSecureNamingChannelArgs(args);
-    if (!new_args.ok()) {
-      LOG(ERROR) << "Failed to create channel args during subchannel creation: "
-                 << new_args.status() << "; Got args: " << args.ToString();
-      return nullptr;
-    }
-    RefCountedPtr<Subchannel> s = Subchannel::Create(
-        MakeOrphanable<Chttp2Connector>(), address, *new_args);
-    return s;
+absl::StatusOr<grpc_channel*> CreateHttp2Channel(std::string target,
+                                                 const ChannelArgs& args) {
+  auto r = ChannelCreate(
+      target,
+      args.SetObject(EndpointTransportClientChannelFactory<Chttp2Connector>()),
+      GRPC_CLIENT_CHANNEL, nullptr);
+  if (r.ok()) {
+    return r->release()->c_ptr();
+  } else {
+    return r.status();
   }
-
- private:
-  static absl::StatusOr<ChannelArgs> GetSecureNamingChannelArgs(
-      ChannelArgs args) {
-    auto* channel_credentials = args.GetObject<grpc_channel_credentials>();
-    if (channel_credentials == nullptr) {
-      return absl::InternalError("channel credentials missing for channel");
-    }
-    // Make sure security connector does not already exist in args.
-    if (args.Contains(GRPC_ARG_SECURITY_CONNECTOR)) {
-      return absl::InternalError(
-          "security connector already present in channel args.");
-    }
-    // Find the authority to use in the security connector.
-    std::optional<std::string> authority =
-        args.GetOwnedString(GRPC_ARG_DEFAULT_AUTHORITY);
-    if (!authority.has_value()) {
-      return absl::InternalError("authority not present in channel args");
-    }
-    // Create the security connector using the credentials and target name.
-    RefCountedPtr<grpc_channel_security_connector>
-        subchannel_security_connector =
-            channel_credentials->create_security_connector(
-                /*call_creds=*/nullptr, authority->c_str(), &args);
-    if (subchannel_security_connector == nullptr) {
-      return absl::InternalError(absl::StrFormat(
-          "Failed to create subchannel for secure name '%s'", *authority));
-    }
-    return args.SetObject(std::move(subchannel_security_connector));
-  }
-};
-
-absl::StatusOr<RefCountedPtr<Channel>> CreateChannel(const char* target,
-                                                     const ChannelArgs& args) {
-  if (target == nullptr) {
-    LOG(ERROR) << "cannot create channel with NULL target name";
-    return absl::InvalidArgumentError("channel target is NULL");
-  }
-  return ChannelCreate(target, args, GRPC_CLIENT_CHANNEL, nullptr);
 }
 
-}  // namespace
 }  // namespace grpc_core
 
-namespace {
-
-grpc_core::Chttp2SecureClientChannelFactory* g_factory;
-gpr_once g_factory_once = GPR_ONCE_INIT;
-
-void FactoryInit() {
-  g_factory = new grpc_core::Chttp2SecureClientChannelFactory();
-}
-
-}  // namespace
-
-// Create a client channel:
-//   Asynchronously: - resolve target
-//                   - connect to it (trying alternatives as presented)
-//                   - perform handshakes
-grpc_channel* grpc_channel_create(const char* target,
-                                  grpc_channel_credentials* creds,
-                                  const grpc_channel_args* c_args) {
-  grpc_core::ExecCtx exec_ctx;
-  GRPC_TRACE_LOG(api, INFO)
-      << "grpc_channel_create(target=" << target << ", creds=" << (void*)creds
-      << ", args=" << (void*)c_args << ")";
-  grpc_channel* channel = nullptr;
-  grpc_error_handle error;
-  if (creds != nullptr) {
-    // Add channel args containing the client channel factory and channel
-    // credentials.
-    gpr_once_init(&g_factory_once, FactoryInit);
-    grpc_core::ChannelArgs args =
-        creds->update_arguments(grpc_core::CoreConfiguration::Get()
-                                    .channel_args_preconditioning()
-                                    .PreconditionChannelArgs(c_args)
-                                    .SetObject(creds->Ref())
-                                    .SetObject(g_factory));
-    // Create channel.
-    auto r = grpc_core::CreateChannel(target, args);
-    if (r.ok()) {
-      channel = r->release()->c_ptr();
-    } else {
-      error = absl_status_to_grpc_error(r.status());
-    }
-  }
-  if (channel == nullptr) {
-    intptr_t integer;
-    grpc_status_code status = GRPC_STATUS_INTERNAL;
-    if (grpc_error_get_int(error, grpc_core::StatusIntProperty::kRpcStatus,
-                           &integer)) {
-      status = static_cast<grpc_status_code>(integer);
-    }
-    channel = grpc_lame_client_channel_create(
-        target, status, "Failed to create client channel");
-  }
-  return channel;
-}
-
 #ifdef GPR_SUPPORT_CHANNELS_FROM_FD
 grpc_channel* grpc_channel_create_from_fd(const char* target, int fd,
                                           grpc_channel_credentials* creds,

src/core/ext/transport/chttp2/client/chttp2_connector.h

@@ -72,6 +72,9 @@ class Chttp2Connector : public SubchannelConnector {
   RefCountedPtr<HandshakeManager> handshake_mgr_;
 };
 
+absl::StatusOr<grpc_channel*> CreateHttp2Channel(std::string target,
+                                                 const ChannelArgs& args);
+
 }  // namespace grpc_core
 
 #endif  // GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_CLIENT_CHTTP2_CONNECTOR_H

src/core/ext/transport/chttp2/server/chttp2_server.h

@@ -51,7 +51,7 @@ class ActiveConnectionTestPeer;
 class HandshakingStateTestPeer;
 }  // namespace testing
 
-// New ChttpServerListener used if experiment "server_listener" is enabled
+// New ChttpServerListener
 class NewChttp2ServerListener : public Server::ListenerInterface {
  public:
   using AcceptorPtr =
@@ -255,6 +255,10 @@ class PassiveListenerImpl final : public PassiveListener {
 };
 
 }  // namespace experimental
+
+absl::StatusOr<int> Chttp2ServerAddPort(Server* server, const char* addr,
+                                        const ChannelArgs& args);
+
 }  // namespace grpc_core
 
 #endif  // GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_SERVER_CHTTP2_SERVER_H

src/core/ext/transport/chttp2/transport/chttp2_transport.cc

@@ -59,7 +59,6 @@
 #include "src/core/call/metadata_info.h"
 #include "src/core/config/config_vars.h"
 #include "src/core/ext/transport/chttp2/transport/call_tracer_wrapper.h"
-#include "src/core/ext/transport/chttp2/transport/context_list_entry.h"
 #include "src/core/ext/transport/chttp2/transport/flow_control.h"
 #include "src/core/ext/transport/chttp2/transport/frame_data.h"
 #include "src/core/ext/transport/chttp2/transport/frame_goaway.h"
@@ -77,6 +76,7 @@
 #include "src/core/ext/transport/chttp2/transport/varint.h"
 #include "src/core/ext/transport/chttp2/transport/write_size_policy.h"
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/event_engine/extensions/channelz.h"
 #include "src/core/lib/event_engine/extensions/tcp_trace.h"
 #include "src/core/lib/event_engine/query_extensions.h"
 #include "src/core/lib/experiments/experiments.h"
@@ -102,18 +102,24 @@
 #include "src/core/lib/transport/transport.h"
 #include "src/core/lib/transport/transport_framing_endpoint_extension.h"
 #include "src/core/telemetry/call_tracer.h"
+#include "src/core/telemetry/context_list_entry.h"
+#include "src/core/telemetry/default_tcp_tracer.h"
 #include "src/core/telemetry/stats.h"
 #include "src/core/telemetry/stats_data.h"
 #include "src/core/util/bitset.h"
 #include "src/core/util/crash.h"
 #include "src/core/util/debug_location.h"
 #include "src/core/util/http_client/parser.h"
+#include "src/core/util/notification.h"
 #include "src/core/util/ref_counted.h"
+#include "src/core/util/shared_bit_gen.h"
 #include "src/core/util/status_helper.h"
 #include "src/core/util/string.h"
 #include "src/core/util/time.h"
 #include "src/core/util/useful.h"
 
+using grpc_core::Json;
+
 #define DEFAULT_CONNECTION_WINDOW_TARGET (1024 * 1024)
 #define MAX_WINDOW 0x7fffffffu
 #define MAX_WRITE_BUFFER_SIZE (64 * 1024 * 1024)
@@ -227,16 +233,6 @@ using EventEngine = ::grpc_event_engine::experimental::EventEngine;
 using TaskHandle = ::grpc_event_engine::experimental::EventEngine::TaskHandle;
 using grpc_core::http2::Http2ErrorCode;
 
-grpc_core::CallTracerAnnotationInterface* ParentCallTracerIfSampled(
-    grpc_chttp2_stream* s) {
-  auto* parent_call_tracer =
-      s->arena->GetContext<grpc_core::CallTracerAnnotationInterface>();
-  if (parent_call_tracer == nullptr || !parent_call_tracer->IsSampled()) {
-    return nullptr;
-  }
-  return parent_call_tracer;
-}
-
 grpc_core::WriteTimestampsCallback g_write_timestamps_callback = nullptr;
 grpc_core::CopyContextFn g_get_copied_context_fn = nullptr;
 }  // namespace
@@ -398,6 +394,10 @@ grpc_chttp2_transport::~grpc_chttp2_transport() {
   }
 }
 
+using grpc_event_engine::experimental::ChannelzExtension;
+using grpc_event_engine::experimental::QueryExtension;
+using grpc_event_engine::experimental::TcpTraceExtension;
+
 static void read_channel_args(grpc_chttp2_transport* t,
                               const grpc_core::ChannelArgs& channel_args,
                               const bool is_client) {
@@ -482,6 +482,15 @@ static void read_channel_args(grpc_chttp2_transport* t,
                          t->peer_string.as_string_view()),
             channel_args
                 .GetObjectRef<grpc_core::channelz::SocketNode::Security>());
+    // Checks channelz_socket, so must be initialized after.
+    t->channelz_data_source =
+        std::make_unique<grpc_chttp2_transport::ChannelzDataSource>(t);
+    auto epte = QueryExtension<ChannelzExtension>(
+        grpc_event_engine::experimental::grpc_get_wrapped_event_engine_endpoint(
+            t->ep.get()));
+    if (epte != nullptr) {
+      epte->SetSocketNode(t->channelz_socket);
+    }
   }
 
   t->ack_pings = channel_args.GetBool("grpc.http2.ack_pings").value_or(true);
@@ -571,6 +580,95 @@ static void init_keepalive_pings_if_enabled_locked(
   }
 }
 
+void grpc_chttp2_transport::ChannelzDataSource::AddData(
+    grpc_core::channelz::DataSink& sink) {
+  grpc_core::Notification n;
+  transport_->event_engine->Run([t = transport_->Ref(), &n, &sink]() {
+    grpc_core::ExecCtx exec_ctx;
+    t->combiner->Run(
+        grpc_core::NewClosure([t, &n, &sink](grpc_error_handle) {
+          Json::Object http2_info;
+          http2_info["flowControl"] =
+              Json::FromObject(t->flow_control.stats().ToJsonObject());
+          Json::Object misc;
+          misc["maxRequestsPerRead"] =
+              Json::FromNumber(static_cast<int64_t>(t->max_requests_per_read));
+          misc["nextStreamId"] = Json::FromNumber(t->next_stream_id);
+          misc["lastNewStreamId"] = Json::FromNumber(t->last_new_stream_id);
+          misc["numIncomingStreamsBeforeSettingsAck"] =
+              Json::FromNumber(t->num_incoming_streams_before_settings_ack);
+          misc["pingAckCount"] =
+              Json::FromNumber(static_cast<int64_t>(t->ping_ack_count));
+          misc["allowTarpit"] = Json::FromBool(t->allow_tarpit);
+          if (t->allow_tarpit) {
+            misc["minTarpitDurationMs"] =
+                Json::FromNumber(t->min_tarpit_duration_ms);
+            misc["maxTarpitDurationMs"] =
+                Json::FromNumber(t->max_tarpit_duration_ms);
+          }
+          misc["keepaliveTime"] =
+              Json::FromString(t->keepalive_time.ToJsonString());
+          misc["nextAdjustedKeepaliveTimestamp"] =
+              Json::FromString((t->next_adjusted_keepalive_timestamp -
+                                grpc_core::Timestamp::Now())
+                                   .ToJsonString());
+          misc["numMessagesInNextWrite"] =
+              Json::FromNumber(t->num_messages_in_next_write);
+          misc["numPendingInducedFrames"] =
+              Json::FromNumber(t->num_pending_induced_frames);
+          misc["writeBufferSize"] = Json::FromNumber(t->write_buffer_size);
+          misc["readingPausedOnPendingInducedFrames"] =
+              Json::FromBool(t->reading_paused_on_pending_induced_frames);
+          misc["enablePreferredRxCryptoFrameAdvertisement"] =
+              Json::FromBool(t->enable_preferred_rx_crypto_frame_advertisement);
+          misc["keepalivePermitWithoutCalls"] =
+              Json::FromBool(t->keepalive_permit_without_calls);
+          misc["bdpPingBlocked"] = Json::FromBool(t->bdp_ping_blocked);
+          misc["bdpPingStarted"] = Json::FromBool(t->bdp_ping_started);
+          misc["ackPings"] = Json::FromBool(t->ack_pings);
+          misc["keepaliveIncomingDataWanted"] =
+              Json::FromBool(t->keepalive_incoming_data_wanted);
+          misc["maxConcurrentStreamsOverloadProtection"] =
+              Json::FromBool(t->max_concurrent_streams_overload_protection);
+          misc["maxConcurrentStreamsRejectOnClient"] =
+              Json::FromBool(t->max_concurrent_streams_reject_on_client);
+          misc["pingOnRstStreamPercent"] =
+              Json::FromNumber(t->ping_on_rst_stream_percent);
+          misc["lastWindowUpdateAge"] = Json::FromString(
+              (grpc_core::Timestamp::Now() - t->last_window_update_time)
+                  .ToJsonString());
+          http2_info["misc"] = Json::FromObject(std::move(misc));
+          http2_info["settings"] = Json::FromObject(t->settings.ToJsonObject());
+          sink.AddAdditionalInfo("http2", std::move(http2_info));
+          std::vector<grpc_core::RefCountedPtr<grpc_core::channelz::BaseNode>>
+              children;
+          children.reserve(t->stream_map.size());
+          for (auto [id, stream] : t->stream_map) {
+            if (stream->channelz_call_node == nullptr) {
+              stream->channelz_call_node =
+                  grpc_core::MakeRefCounted<grpc_core::channelz::CallNode>(
+                      absl::StrCat("chttp2 ",
+                                   t->is_client ? "client" : "server",
+                                   " stream ", stream->id));
+            }
+            children.push_back(stream->channelz_call_node);
+          }
+          sink.AddChildObjects(std::move(children));
+          n.Notify();
+        }),
+        absl::OkStatus());
+  });
+  n.WaitForNotification();
+}
+
+std::unique_ptr<grpc_core::channelz::ZTrace>
+grpc_chttp2_transport::ChannelzDataSource::GetZTrace(absl::string_view name) {
+  if (name == "transport_frames") {
+    return transport_->http2_ztrace_collector.MakeZTrace();
+  }
+  return grpc_core::channelz::DataSource::GetZTrace(name);
+}
+
 // TODO(alishananda): add unit testing as part of chttp2 promise conversion work
 void grpc_chttp2_transport::WriteSecurityFrame(grpc_core::SliceBuffer* data) {
   grpc_core::ExecCtx exec_ctx;
@@ -601,9 +699,6 @@ void grpc_chttp2_transport::WriteSecurityFrameLocked(
   grpc_chttp2_initiate_write(this, GRPC_CHTTP2_INITIATE_WRITE_SEND_MESSAGE);
 }
 
-using grpc_event_engine::experimental::QueryExtension;
-using grpc_event_engine::experimental::TcpTraceExtension;
-
 grpc_chttp2_transport::grpc_chttp2_transport(
     const grpc_core::ChannelArgs& channel_args,
     grpc_core::OrphanablePtr<grpc_endpoint> endpoint, const bool is_client)
@@ -639,7 +734,9 @@ grpc_chttp2_transport::grpc_chttp2_transport(
         grpc_event_engine::experimental::grpc_get_wrapped_event_engine_endpoint(
             ep.get()));
     if (epte != nullptr) {
-      epte->InitializeAndReturnTcpTracer();
+      epte->SetTcpTracer(std::make_shared<grpc_core::DefaultTcpTracer>(
+          channel_args.GetObjectRef<
+              grpc_core::GlobalStatsPluginRegistry::StatsPluginGroup>()));
     }
   }
 
@@ -1088,6 +1185,8 @@ static void write_action(grpc_chttp2_transport* t) {
       << (t->is_client ? "CLIENT" : "SERVER") << "[" << t << "]: Write "
       << t->outbuf.Length() << " bytes";
   t->write_size_policy.BeginWrite(t->outbuf.Length());
+  t->http2_ztrace_collector.Append(grpc_core::H2BeginEndpointWrite{
+      static_cast<uint32_t>(t->outbuf.Length())});
   grpc_endpoint_write(t->ep.get(), t->outbuf.c_slice_buffer(),
                       grpc_core::InitTransportClosure<write_action_end>(
                           t->Ref(), &t->write_action_end_locked),
@@ -1369,22 +1468,12 @@ static void log_metadata(const grpc_metadata_batch* md_batch, uint32_t id,
 }
 
 static void trace_annotations(grpc_chttp2_stream* s) {
-  if (!grpc_core::IsCallTracerTransportFixEnabled()) {
-    if (s->parent_call_tracer != nullptr) {
-      s->parent_call_tracer->RecordAnnotation(
-          grpc_core::HttpAnnotation(grpc_core::HttpAnnotation::Type::kStart,
-                                    gpr_now(GPR_CLOCK_REALTIME))
-              .Add(s->t->flow_control.stats())
-              .Add(s->flow_control.stats()));
-    }
-  } else {
-    if (s->call_tracer != nullptr && s->call_tracer->IsSampled()) {
-      s->call_tracer->RecordAnnotation(
-          grpc_core::HttpAnnotation(grpc_core::HttpAnnotation::Type::kStart,
-                                    gpr_now(GPR_CLOCK_REALTIME))
-              .Add(s->t->flow_control.stats())
-              .Add(s->flow_control.stats()));
-    }
+  if (s->call_tracer != nullptr && s->call_tracer->IsSampled()) {
+    s->call_tracer->RecordAnnotation(
+        grpc_core::HttpAnnotation(grpc_core::HttpAnnotation::Type::kStart,
+                                  gpr_now(GPR_CLOCK_REALTIME))
+            .Add(s->t->flow_control.stats())
+            .Add(s->flow_control.stats()));
   }
 }
 
@@ -1633,9 +1722,6 @@ static void perform_stream_op_locked(void* stream_op,
   grpc_chttp2_transport* t = s->t.get();
 
   s->traced = op->is_traced;
-  if (!grpc_core::IsCallTracerTransportFixEnabled()) {
-    s->parent_call_tracer = ParentCallTracerIfSampled(s);
-  }
   // Some server filters populate CallTracerInterface in the context only after
   // reading initial metadata. (Client-side population is done by
   // client_channel filter.)
@@ -1919,7 +2005,8 @@ class GracefulGoaway : public grpc_core::RefCounted<GracefulGoaway> {
     // Graceful GOAWAYs require a NO_ERROR error code
     grpc_chttp2_goaway_append(
         (1u << 31) - 1, 0 /*NO_ERROR*/,
-        grpc_core::Slice::FromCopiedString(message_).TakeCSlice(), &t->qbuf);
+        grpc_core::Slice::FromCopiedString(message_).TakeCSlice(), &t->qbuf,
+        &t->http2_ztrace_collector);
     t->keepalive_timeout =
         std::min(t->keepalive_timeout, grpc_core::Duration::Seconds(20));
     t->ping_timeout =
@@ -1953,7 +2040,8 @@ class GracefulGoaway : public grpc_core::RefCounted<GracefulGoaway> {
     t_->sent_goaway_state = GRPC_CHTTP2_FINAL_GOAWAY_SEND_SCHEDULED;
     grpc_chttp2_goaway_append(
         t_->last_new_stream_id, 0 /*NO_ERROR*/,
-        grpc_core::Slice::FromCopiedString(message_).TakeCSlice(), &t_->qbuf);
+        grpc_core::Slice::FromCopiedString(message_).TakeCSlice(), &t_->qbuf,
+        &t_->http2_ztrace_collector);
     grpc_chttp2_initiate_write(t_.get(),
                                GRPC_CHTTP2_INITIATE_WRITE_GOAWAY_SENT);
   }
@@ -1999,9 +2087,10 @@ static void send_goaway(grpc_chttp2_transport* t, grpc_error_handle error,
             << ": Sending goaway last_new_stream_id=" << t->last_new_stream_id
             << " err=" << grpc_core::StatusToString(error);
     t->sent_goaway_state = GRPC_CHTTP2_FINAL_GOAWAY_SEND_SCHEDULED;
-    grpc_chttp2_goaway_append(
-        t->last_new_stream_id, static_cast<uint32_t>(http_error),
-        grpc_slice_from_cpp_string(std::move(message)), &t->qbuf);
+    grpc_chttp2_goaway_append(t->last_new_stream_id,
+                              static_cast<uint32_t>(http_error),
+                              grpc_slice_from_cpp_string(std::move(message)),
+                              &t->qbuf, &t->http2_ztrace_collector);
   } else {
     // Final GOAWAY has already been sent.
   }
@@ -2255,7 +2344,7 @@ namespace {
 
 Duration TarpitDuration(grpc_chttp2_transport* t) {
   return Duration::Milliseconds(absl::LogUniform<int>(
-      absl::BitGen(), t->min_tarpit_duration_ms, t->max_tarpit_duration_ms));
+      SharedBitGen(), t->min_tarpit_duration_ms, t->max_tarpit_duration_ms));
 }
 
 template <typename F>
@@ -3332,13 +3421,6 @@ absl::string_view grpc_chttp2_transport::GetTransportName() const {
   return "chttp2";
 }
 
-grpc_core::RefCountedPtr<grpc_core::channelz::SocketNode>
-grpc_chttp2_transport_get_socket_node(grpc_core::Transport* transport) {
-  grpc_chttp2_transport* t =
-      reinterpret_cast<grpc_chttp2_transport*>(transport);
-  return t->channelz_socket;
-}
-
 grpc_core::Transport* grpc_create_chttp2_transport(
     const grpc_core::ChannelArgs& channel_args,
     grpc_core::OrphanablePtr<grpc_endpoint> ep, const bool is_client) {

src/core/ext/transport/chttp2/transport/chttp2_transport.h

@@ -46,9 +46,6 @@ grpc_core::Transport* grpc_create_chttp2_transport(
     const grpc_core::ChannelArgs& channel_args,
     grpc_core::OrphanablePtr<grpc_endpoint> ep, bool is_client);
 
-grpc_core::RefCountedPtr<grpc_core::channelz::SocketNode>
-grpc_chttp2_transport_get_socket_node(grpc_core::Transport* transport);
-
 /// Takes ownership of \a read_buffer, which (if non-NULL) contains
 /// leftover bytes previously read from the endpoint (e.g., by handshakers).
 /// If non-null, \a notify_on_receive_settings will be scheduled when

src/core/ext/transport/chttp2/transport/flow_control.h

@@ -302,6 +302,24 @@ class TransportFlowControl final {
     double bdp_bw_est;
 
     std::string ToString() const;
+    Json::Object ToJsonObject() {
+      Json::Object object;
+      object["targetWindow"] = Json::FromNumber(target_window);
+      object["targetFrameSize"] = Json::FromNumber(target_frame_size);
+      object["targetPreferredRxCryptoFrameSize"] =
+          Json::FromNumber(target_preferred_rx_crypto_frame_size);
+      object["ackedInitWindow"] = Json::FromNumber(acked_init_window);
+      object["queuedInitWindow"] = Json::FromNumber(queued_init_window);
+      object["sentInitWindow"] = Json::FromNumber(sent_init_window);
+      object["remoteWindow"] = Json::FromNumber(remote_window);
+      object["announcedWindow"] = Json::FromNumber(announced_window);
+      object["announcedStreamTotalOverIncomingWindow"] =
+          Json::FromNumber(announced_stream_total_over_incoming_window);
+      object["bdpAccumulator"] = Json::FromNumber(bdp_accumulator);
+      object["bdpEstimate"] = Json::FromNumber(bdp_estimate);
+      object["bdpBwEst"] = Json::FromNumber(bdp_bw_est);
+      return object;
+    }
   };
 
   Stats stats() const {

src/core/ext/transport/chttp2/transport/frame.cc

@@ -24,13 +24,21 @@
 #include "absl/log/check.h"
 #include "absl/status/status.h"
 #include "absl/strings/str_cat.h"
+#include "src/core/lib/slice/slice.h"
 #include "src/core/lib/slice/slice_buffer.h"
 #include "src/core/util/crash.h"
 
+using grpc_core::http2::Http2ErrorCode;
+using grpc_core::http2::Http2Status;
+using grpc_core::http2::ValueOrHttp2Status;
+
 namespace grpc_core {
 
 namespace {
 
+// TODO(tjagtap) TODO(akshitpatel): [PH2][P3] : Write micro benchmarks for
+// framing code
+
 // HTTP2 Frame Types
 enum class FrameType : uint8_t {
   kData = 0,
@@ -73,6 +81,21 @@ uint32_t Read3b(const uint8_t* input) {
          static_cast<uint32_t>(input[1]) << 8 | static_cast<uint32_t>(input[2]);
 }
 
+constexpr uint32_t k8BitMask = 0x7f;
+
+void Write31bits(uint32_t x, uint8_t* output) {
+  output[0] = static_cast<uint8_t>(k8BitMask & (x >> 24));
+  output[1] = static_cast<uint8_t>(x >> 16);
+  output[2] = static_cast<uint8_t>(x >> 8);
+  output[3] = static_cast<uint8_t>(x);
+}
+
+uint32_t Read31bits(const uint8_t* input) {
+  return (k8BitMask & static_cast<uint32_t>(input[0])) << 24 |
+         static_cast<uint32_t>(input[1]) << 16 |
+         static_cast<uint32_t>(input[2]) << 8 | static_cast<uint32_t>(input[3]);
+}
+
 void Write4b(uint32_t x, uint8_t* output) {
   output[0] = static_cast<uint8_t>(x >> 24);
   output[1] = static_cast<uint8_t>(x >> 16);
@@ -129,7 +152,7 @@ class SerializeExtraBytesRequired {
   size_t operator()(const Http2WindowUpdateFrame&) { return 4; }
   size_t operator()(const Http2SecurityFrame&) { return 0; }
   size_t operator()(const Http2UnknownFrame&) { Crash("unreachable"); }
-  size_t operator()(const Http2EmptyFrame&) { Crash("unreachable"); }
+  size_t operator()(const Http2EmptyFrame&) { return 0; }
 };
 
 class SerializeHeaderAndPayload {
@@ -215,8 +238,12 @@ class SerializeHeaderAndPayload {
     Http2FrameHeader{static_cast<uint32_t>(8 + frame.debug_data.length()),
                      static_cast<uint8_t>(FrameType::kGoaway), 0, 0}
         .Serialize(hdr_and_fixed_payload.begin());
-    Write4b(frame.last_stream_id,
-            hdr_and_fixed_payload.begin() + kFrameHeaderSize);
+    if (GPR_UNLIKELY(frame.last_stream_id > RFC9113::kMaxStreamId31Bit)) {
+      LOG(ERROR) << "Stream ID will be truncated. The MSB will be set to 0 "
+                 << frame.last_stream_id;
+    }
+    Write31bits(frame.last_stream_id,
+                hdr_and_fixed_payload.begin() + kFrameHeaderSize);
     Write4b(frame.error_code,
             hdr_and_fixed_payload.begin() + kFrameHeaderSize + 4);
     out_.AppendIndexed(Slice(std::move(hdr_and_fixed_payload)));
@@ -228,7 +255,12 @@ class SerializeHeaderAndPayload {
     Http2FrameHeader{4, static_cast<uint8_t>(FrameType::kWindowUpdate), 0,
                      frame.stream_id}
         .Serialize(hdr_and_payload.begin());
-    Write4b(frame.increment, hdr_and_payload.begin() + kFrameHeaderSize);
+    if (GPR_UNLIKELY(frame.increment > RFC9113::kMaxStreamId31Bit)) {
+      LOG(ERROR) << "Http2WindowUpdateFrame increment will be truncated to 31 "
+                    "bits. The MSB will be set to 0 "
+                 << frame.increment;
+    }
+    Write31bits(frame.increment, hdr_and_payload.begin() + kFrameHeaderSize);
     out_.AppendIndexed(Slice(std::move(hdr_and_payload)));
   }
 
@@ -250,109 +282,162 @@ class SerializeHeaderAndPayload {
   MutableSlice extra_bytes_;
 };
 
-absl::Status StripPadding(SliceBuffer& payload) {
-  if (payload.Length() < 1) {
-    return absl::InternalError("padding flag set but no padding byte");
+Http2Status StripPadding(const Http2FrameHeader& hdr, SliceBuffer& payload) {
+  if (GPR_UNLIKELY(payload.Length() < 1)) {
+    return Http2Status::Http2ConnectionError(
+        Http2ErrorCode::kProtocolError,
+        absl::StrCat(RFC9113::kFrameParserIncorrectPadding, hdr.ToString()));
   }
+  const size_t payload_size = payload.Length();
   uint8_t padding_bytes;
   payload.MoveFirstNBytesIntoBuffer(1, &padding_bytes);
-  if (payload.Length() < padding_bytes) {
-    return absl::InternalError("padding flag set but not enough padding bytes");
+
+  if (GPR_UNLIKELY(payload_size <= padding_bytes)) {
+    return Http2Status::Http2ConnectionError(
+        Http2ErrorCode::kProtocolError,
+        absl::StrCat(RFC9113::kPaddingLengthLargerThanFrameLength,
+                     hdr.ToString()));
   }
+
+  // We dont check for padding being zero.
+  // No point checking bytes that will be discarded.
+  // RFC9113 : A receiver is not obligated to verify padding but MAY treat
+  // non-zero padding as a connection error of type PROTOCOL_ERROR.
   payload.RemoveLastNBytes(padding_bytes);
-  return absl::OkStatus();
+  return Http2Status::Ok();
 }
 
-absl::StatusOr<Http2DataFrame> ParseDataFrame(const Http2FrameHeader& hdr,
+ValueOrHttp2Status<Http2Frame> ParseDataFrame(const Http2FrameHeader& hdr,
                                               SliceBuffer& payload) {
-  if (hdr.stream_id == 0) {
-    return absl::InternalError(
-        absl::StrCat("invalid stream id: ", hdr.ToString()));
+  if (GPR_UNLIKELY((hdr.stream_id % 2) == 0)) {
+    if ((hdr.stream_id == 0)) {
+      return Http2Status::Http2ConnectionError(
+          Http2ErrorCode::kProtocolError,
+          absl::StrCat(RFC9113::kDataStreamIdMustBeNonZero, hdr.ToString()));
+    } else {
+      return Http2Status::Http2ConnectionError(
+          Http2ErrorCode::kProtocolError,
+          absl::StrCat(RFC9113::kStreamIdMustBeOdd, hdr.ToString()));
+    }
   }
 
   if (hdr.flags & kFlagPadded) {
-    auto s = StripPadding(payload);
-    if (!s.ok()) return s;
+    Http2Status s = StripPadding(hdr, payload);
+    if (GPR_UNLIKELY(!s.IsOk())) {
+      return ValueOrHttp2Status<Http2Frame>(std::move(s));
+    }
   }
 
-  return Http2DataFrame{hdr.stream_id, ExtractFlag(hdr.flags, kFlagEndStream),
-                        std::move(payload)};
+  return ValueOrHttp2Status<Http2Frame>(
+      Http2DataFrame{hdr.stream_id, ExtractFlag(hdr.flags, kFlagEndStream),
+                     std::move(payload)});
 }
 
-absl::StatusOr<Http2HeaderFrame> ParseHeaderFrame(const Http2FrameHeader& hdr,
-                                                  SliceBuffer& payload) {
-  if (hdr.stream_id == 0) {
-    return absl::InternalError(
-        absl::StrCat("invalid stream id: ", hdr.ToString()));
+ValueOrHttp2Status<Http2Frame> ParseHeaderFrame(const Http2FrameHeader& hdr,
+                                                SliceBuffer& payload) {
+  if (GPR_UNLIKELY((hdr.stream_id % 2) == 0)) {
+    if (hdr.stream_id == 0) {
+      return Http2Status::Http2ConnectionError(
+          Http2ErrorCode::kProtocolError,
+          absl::StrCat(RFC9113::kHeaderStreamIdMustBeNonZero, hdr.ToString()));
+    } else {
+      return Http2Status::Http2ConnectionError(
+          Http2ErrorCode::kProtocolError,
+          absl::StrCat(RFC9113::kStreamIdMustBeOdd, hdr.ToString()));
+    }
   }
 
   if (hdr.flags & kFlagPadded) {
-    auto s = StripPadding(payload);
-    if (!s.ok()) return s;
+    Http2Status s = StripPadding(hdr, payload);
+    if (GPR_UNLIKELY(!s.IsOk())) {
+      return ValueOrHttp2Status<Http2Frame>(std::move(s));
+    }
   }
 
-  if (hdr.flags & kFlagPriority) {
-    if (payload.Length() < 5) {
-      return absl::InternalError(
-          absl::StrCat("invalid priority payload: ", hdr.ToString()));
+  if (GPR_UNLIKELY(hdr.flags & kFlagPriority)) {
+    if (GPR_UNLIKELY(payload.Length() < 5)) {
+      return Http2Status::Http2ConnectionError(
+          Http2ErrorCode::kProtocolError,
+          absl::StrCat(RFC9113::kIncorrectFrame, hdr.ToString()));
     }
     uint8_t trash[5];
     payload.MoveFirstNBytesIntoBuffer(5, trash);
   }
 
-  return Http2HeaderFrame{
+  return ValueOrHttp2Status<Http2Frame>(Http2HeaderFrame{
       hdr.stream_id, ExtractFlag(hdr.flags, kFlagEndHeaders),
-      ExtractFlag(hdr.flags, kFlagEndStream), std::move(payload)};
+      ExtractFlag(hdr.flags, kFlagEndStream), std::move(payload)});
 }
 
-absl::StatusOr<Http2ContinuationFrame> ParseContinuationFrame(
+ValueOrHttp2Status<Http2Frame> ParseContinuationFrame(
     const Http2FrameHeader& hdr, SliceBuffer& payload) {
-  if (hdr.stream_id == 0) {
-    return absl::InternalError(
-        absl::StrCat("invalid stream id: ", hdr.ToString()));
+  if (GPR_UNLIKELY((hdr.stream_id % 2) == 0)) {
+    if (hdr.stream_id == 0) {
+      return Http2Status::Http2ConnectionError(
+          Http2ErrorCode::kProtocolError,
+          absl::StrCat(RFC9113::kContinuationStreamIdMustBeNonZero,
+                       hdr.ToString()));
+    } else {
+      return Http2Status::Http2ConnectionError(
+          Http2ErrorCode::kProtocolError,
+          absl::StrCat(RFC9113::kStreamIdMustBeOdd, hdr.ToString()));
+    }
   }
 
-  return Http2ContinuationFrame{hdr.stream_id,
-                                ExtractFlag(hdr.flags, kFlagEndHeaders),
-                                std::move(payload)};
+  return ValueOrHttp2Status<Http2Frame>(Http2ContinuationFrame{
+      hdr.stream_id, ExtractFlag(hdr.flags, kFlagEndHeaders),
+      std::move(payload)});
 }
 
-absl::StatusOr<Http2RstStreamFrame> ParseRstStreamFrame(
-    const Http2FrameHeader& hdr, SliceBuffer& payload) {
-  if (payload.Length() != 4) {
-    return absl::InternalError(
-        absl::StrCat("invalid rst stream payload: ", hdr.ToString()));
+ValueOrHttp2Status<Http2Frame> ParseRstStreamFrame(const Http2FrameHeader& hdr,
+                                                   SliceBuffer& payload) {
+  if (GPR_UNLIKELY(payload.Length() != 4)) {
+    return Http2Status::Http2ConnectionError(
+        Http2ErrorCode::kFrameSizeError,
+        absl::StrCat(RFC9113::kRstStreamLength4, hdr.ToString()));
   }
 
-  if (hdr.stream_id == 0) {
-    return absl::InternalError(
-        absl::StrCat("invalid stream id: ", hdr.ToString()));
+  if (GPR_UNLIKELY((hdr.stream_id % 2) == 0)) {
+    if ((hdr.stream_id == 0)) {
+      return Http2Status::Http2ConnectionError(
+          Http2ErrorCode::kProtocolError,
+          absl::StrCat(RFC9113::kRstStreamStreamIdMustBeNonZero,
+                       hdr.ToString()));
+    } else {
+      return Http2Status::Http2ConnectionError(
+          Http2ErrorCode::kProtocolError,
+          absl::StrCat(RFC9113::kStreamIdMustBeOdd, hdr.ToString()));
+    }
   }
 
   uint8_t buffer[4];
   payload.CopyToBuffer(buffer);
 
-  return Http2RstStreamFrame{hdr.stream_id, Read4b(buffer)};
+  return ValueOrHttp2Status<Http2Frame>(
+      Http2RstStreamFrame{hdr.stream_id, Read4b(buffer)});
 }
 
-absl::StatusOr<Http2SettingsFrame> ParseSettingsFrame(
-    const Http2FrameHeader& hdr, SliceBuffer& payload) {
-  if (hdr.stream_id != 0) {
-    return absl::InternalError(
-        absl::StrCat("invalid stream id: ", hdr.ToString()));
-  }
-  if (hdr.flags == kFlagAck) {
-    if (payload.Length() != 0) {
-      return absl::InternalError(
-          absl::StrCat("invalid settings ack length: ", hdr.ToString()));
-    }
-    return Http2SettingsFrame{true, {}};
+ValueOrHttp2Status<Http2Frame> ParseSettingsFrame(const Http2FrameHeader& hdr,
+                                                  SliceBuffer& payload) {
+  if (GPR_UNLIKELY(hdr.stream_id != 0)) {
+    return Http2Status::Http2ConnectionError(
+        Http2ErrorCode::kProtocolError,
+        absl::StrCat(RFC9113::kSettingsStreamIdMustBeZero, hdr.ToString()));
   }
 
-  if (payload.Length() % 6 != 0) {
-    return absl::InternalError(
-        absl::StrCat("invalid settings payload: ", hdr.ToString(),
-                     " -- settings must be multiples of 6 bytes long"));
+  if (hdr.flags & kFlagAck) {
+    if (GPR_UNLIKELY(payload.Length() != 0)) {
+      return Http2Status::Http2ConnectionError(
+          Http2ErrorCode::kFrameSizeError,
+          absl::StrCat(RFC9113::kSettingsLength0, hdr.ToString()));
+    }
+    return ValueOrHttp2Status<Http2Frame>(Http2SettingsFrame{true, {}});
+  }
+
+  if (GPR_UNLIKELY(payload.Length() % 6 != 0)) {
+    return Http2Status::Http2ConnectionError(
+        Http2ErrorCode::kFrameSizeError,
+        absl::StrCat(RFC9113::kSettingsLength6x, hdr.ToString()));
   }
 
   Http2SettingsFrame frame{false, {}};
@@ -364,19 +449,21 @@ absl::StatusOr<Http2SettingsFrame> ParseSettingsFrame(
         Read4b(buffer + 2),
     });
   }
-  return std::move(frame);
+  return ValueOrHttp2Status<Http2Frame>(std::move(frame));
 }
 
-absl::StatusOr<Http2PingFrame> ParsePingFrame(const Http2FrameHeader& hdr,
+ValueOrHttp2Status<Http2Frame> ParsePingFrame(const Http2FrameHeader& hdr,
                                               SliceBuffer& payload) {
-  if (payload.Length() != 8) {
-    return absl::InternalError(
-        absl::StrCat("invalid ping payload: ", hdr.ToString()));
+  if (GPR_UNLIKELY(payload.Length() != 8)) {
+    return Http2Status::Http2ConnectionError(
+        Http2ErrorCode::kFrameSizeError,
+        absl::StrCat(RFC9113::kPingLength8, hdr.ToString()));
   }
 
-  if (hdr.stream_id != 0) {
-    return absl::InternalError(
-        absl::StrCat("invalid ping stream id: ", hdr.ToString()));
+  if (GPR_UNLIKELY(hdr.stream_id != 0)) {
+    return Http2Status::Http2ConnectionError(
+        Http2ErrorCode::kProtocolError,
+        absl::StrCat(RFC9113::kPingStreamIdMustBeZero, hdr.ToString()));
   }
 
   // RFC9113 : Unused flags MUST be ignored on receipt and MUST be left unset
@@ -386,49 +473,65 @@ absl::StatusOr<Http2PingFrame> ParsePingFrame(const Http2FrameHeader& hdr,
   uint8_t buffer[8];
   payload.CopyToBuffer(buffer);
 
-  return Http2PingFrame{ack, Read8b(buffer)};
+  return ValueOrHttp2Status<Http2Frame>(Http2PingFrame{ack, Read8b(buffer)});
 }
 
-absl::StatusOr<Http2GoawayFrame> ParseGoawayFrame(const Http2FrameHeader& hdr,
-                                                  SliceBuffer& payload) {
-  if (payload.Length() < 8) {
-    return absl::InternalError(
-        absl::StrCat("invalid goaway payload: ", hdr.ToString(),
-                     " -- must be at least 8 bytes"));
+ValueOrHttp2Status<Http2Frame> ParseGoawayFrame(const Http2FrameHeader& hdr,
+                                                SliceBuffer& payload) {
+  if (GPR_UNLIKELY(payload.Length() < 8)) {
+    return Http2Status::Http2ConnectionError(
+        Http2ErrorCode::kFrameSizeError,
+        absl::StrCat(RFC9113::kGoAwayLength8, hdr.ToString()));
   }
 
-  if (hdr.stream_id != 0) {
-    return absl::InternalError(
-        absl::StrCat("invalid goaway stream id: ", hdr.ToString()));
+  if (GPR_UNLIKELY(hdr.stream_id != 0)) {
+    return Http2Status::Http2ConnectionError(
+        Http2ErrorCode::kProtocolError,
+        absl::StrCat(RFC9113::kGoAwayStreamIdMustBeZero, hdr.ToString()));
   }
 
   uint8_t buffer[8];
   payload.MoveFirstNBytesIntoBuffer(8, buffer);
-  return Http2GoawayFrame{Read4b(buffer), Read4b(buffer + 4),
-                          payload.JoinIntoSlice()};
+  return ValueOrHttp2Status<Http2Frame>(Http2GoawayFrame{
+      /*Last-Stream-ID (31)*/ Read31bits(buffer),
+      /*Error Code (32)*/ Read4b(buffer + 4),
+      /*Additional Debug Data(variable)*/ payload.JoinIntoSlice()});
 }
 
-absl::StatusOr<Http2WindowUpdateFrame> ParseWindowUpdateFrame(
+ValueOrHttp2Status<Http2Frame> ParseWindowUpdateFrame(
     const Http2FrameHeader& hdr, SliceBuffer& payload) {
-  if (payload.Length() != 4) {
-    return absl::InternalError(
-        absl::StrCat("invalid window update payload: ", hdr.ToString(),
-                     " -- must be 4 bytes"));
+  if (GPR_UNLIKELY(payload.Length() != 4)) {
+    return Http2Status::Http2ConnectionError(
+        Http2ErrorCode::kFrameSizeError,
+        absl::StrCat(RFC9113::kWindowUpdateLength4, hdr.ToString()));
   }
-
-  if (hdr.flags != 0) {
-    return absl::InternalError(
-        absl::StrCat("invalid window update flags: ", hdr.ToString()));
+  if (GPR_UNLIKELY(hdr.stream_id > 0u && (hdr.stream_id % 2) == 0)) {
+    return Http2Status::Http2ConnectionError(
+        Http2ErrorCode::kProtocolError,
+        absl::StrCat(RFC9113::kStreamIdMustBeOdd, hdr.ToString()));
   }
-
   uint8_t buffer[4];
   payload.CopyToBuffer(buffer);
-  return Http2WindowUpdateFrame{hdr.stream_id, Read4b(buffer)};
+  const uint32_t window_size_increment = Read31bits(buffer);
+  if (GPR_UNLIKELY(window_size_increment == 0)) {
+    if (hdr.stream_id == 0) {
+      return Http2Status::Http2ConnectionError(
+          Http2ErrorCode::kProtocolError,
+          absl::StrCat(RFC9113::kWindowSizeIncrement, hdr.ToString()));
+    } else {
+      return Http2Status::Http2StreamError(
+          Http2ErrorCode::kProtocolError,
+          absl::StrCat(RFC9113::kWindowSizeIncrement, hdr.ToString()));
+    }
+  }
+  return ValueOrHttp2Status<Http2Frame>(
+      Http2WindowUpdateFrame{hdr.stream_id, window_size_increment});
 }
 
-absl::StatusOr<Http2SecurityFrame> ParseSecurityFrame(
+ValueOrHttp2Status<Http2Frame> ParseSecurityFrame(
     const Http2FrameHeader& /*hdr*/, SliceBuffer& payload) {
-  return Http2SecurityFrame{std::move(payload)};
+  // TODO(tjagtap) : [PH2][P3] : Add validations
+  return ValueOrHttp2Status<Http2Frame>(Http2SecurityFrame{std::move(payload)});
 }
 
 }  // namespace
@@ -441,7 +544,11 @@ void Http2FrameHeader::Serialize(uint8_t* output) const {
 }
 
 Http2FrameHeader Http2FrameHeader::Parse(const uint8_t* input) {
-  return Http2FrameHeader{Read3b(input), input[3], input[4], Read4b(input + 5)};
+  return Http2FrameHeader{
+      /* Length(24) */ Read3b(input),
+      /* Type(8) */ input[3],
+      /* Flags(8) */ input[4],
+      /* Reserved(1), Stream Identifier(31) */ Read31bits(input + 5)};
 }
 
 namespace {
@@ -493,9 +600,10 @@ void Serialize(absl::Span<Http2Frame> frames, SliceBuffer& out) {
   }
 }
 
-absl::StatusOr<Http2Frame> ParseFramePayload(const Http2FrameHeader& hdr,
-                                             SliceBuffer payload) {
+http2::ValueOrHttp2Status<Http2Frame> ParseFramePayload(
+    const Http2FrameHeader& hdr, SliceBuffer payload) {
   CHECK(payload.Length() == hdr.length);
+
   switch (static_cast<FrameType>(hdr.type)) {
     case FrameType::kData:
       return ParseDataFrame(hdr, payload);
@@ -514,20 +622,20 @@ absl::StatusOr<Http2Frame> ParseFramePayload(const Http2FrameHeader& hdr,
     case FrameType::kWindowUpdate:
       return ParseWindowUpdateFrame(hdr, payload);
     case FrameType::kPushPromise:
-      return absl::InternalError(
-          "push promise not supported (and SETTINGS_ENABLE_PUSH explicitly "
-          "disabled).");
+      return Http2Status::Http2ConnectionError(
+          Http2ErrorCode::kProtocolError,
+          absl::StrCat(RFC9113::kNoPushPromise, hdr.ToString()));
     case FrameType::kCustomSecurity:
       return ParseSecurityFrame(hdr, payload);
     default:
-      return Http2UnknownFrame{};
+      return ValueOrHttp2Status<Http2Frame>(Http2UnknownFrame{});
   }
 }
 
 GrpcMessageHeader ExtractGrpcHeader(SliceBuffer& payload) {
   CHECK_GE(payload.Length(), kGrpcHeaderSizeInBytes);
   uint8_t buffer[kGrpcHeaderSizeInBytes];
-  payload.MoveFirstNBytesIntoBuffer(kGrpcHeaderSizeInBytes, buffer);
+  payload.CopyFirstNBytesIntoBuffer(kGrpcHeaderSizeInBytes, buffer);
   GrpcMessageHeader header;
   header.flags = buffer[0];
   header.length = Read4b(buffer + 1);

src/core/ext/transport/chttp2/transport/frame.h

@@ -25,6 +25,7 @@
 #include "absl/status/statusor.h"
 #include "absl/strings/string_view.h"
 #include "absl/types/span.h"
+#include "src/core/ext/transport/chttp2/transport/http2_status.h"
 #include "src/core/lib/slice/slice.h"
 #include "src/core/lib/slice/slice_buffer.h"
 
@@ -156,8 +157,8 @@ struct Http2GoawayFrame {
 
 // WINDOW_UPDATE frame
 struct Http2WindowUpdateFrame {
-  uint32_t stream_id;
-  uint32_t increment;
+  uint32_t stream_id = 0;
+  uint32_t increment = 0;
 
   bool operator==(const Http2WindowUpdateFrame& other) const {
     return stream_id == other.stream_id && increment == other.increment;
@@ -229,8 +230,8 @@ struct Http2FrameHeader {
 // If a frame should simply be ignored, this function returns a
 // Http2UnknownFrame.
 // It is expected that hdr.length == payload.Length().
-absl::StatusOr<Http2Frame> ParseFramePayload(const Http2FrameHeader& hdr,
-                                             SliceBuffer payload);
+http2::ValueOrHttp2Status<Http2Frame> ParseFramePayload(
+    const Http2FrameHeader& hdr, SliceBuffer payload);
 
 // Serialize frame and append to out, leaves frames in an unknown state (may
 // move things out of frames)
@@ -242,8 +243,8 @@ void Serialize(absl::Span<Http2Frame> frames, SliceBuffer& out);
 constexpr uint8_t kGrpcHeaderSizeInBytes = 5;
 
 struct GrpcMessageHeader {
-  uint8_t flags;
-  uint32_t length;
+  uint8_t flags = 0;
+  uint32_t length = 0;
 };
 
 // If the payload SliceBuffer is too small to hold a gRPC header, this function
@@ -254,6 +255,77 @@ GrpcMessageHeader ExtractGrpcHeader(SliceBuffer& payload);
 void AppendGrpcHeaderToSliceBuffer(SliceBuffer& payload, const uint8_t flags,
                                    const uint32_t length);
 
+namespace RFC9113 {
+// RFC9113: 5.1.1.
+inline constexpr absl::string_view kStreamIdMustBeOdd =
+    "RFC9113: Streams initiated by a client MUST use odd-numbered stream "
+    "identifiers";  // gRPC streams are only initiated by a client.
+
+// 6.
+// Stream Identifier related errors
+// Non-Zero Stream Identifier
+inline constexpr absl::string_view kDataStreamIdMustBeNonZero =
+    "RFC9113: DATA frames MUST be associated with a stream";
+inline constexpr absl::string_view kHeaderStreamIdMustBeNonZero =
+    "RFC9113: HEADERS frames MUST be associated with a stream";
+inline constexpr absl::string_view kContinuationStreamIdMustBeNonZero =
+    "RFC9113: CONTINUATION frames MUST be associated with a stream";
+inline constexpr absl::string_view kRstStreamStreamIdMustBeNonZero =
+    "RFC9113: RST_STREAM frames frames MUST be associated with a stream";
+
+// Zero Stream Identifier
+inline constexpr absl::string_view kPingStreamIdMustBeZero =
+    "RFC9113: If a PING frame is received with a Stream Identifier field "
+    "value other than 0x00, the recipient MUST respond with a connection error";
+inline constexpr absl::string_view kGoAwayStreamIdMustBeZero =
+    "RFC9113: An endpoint MUST treat a GOAWAY frame with a stream identifier "
+    "other than 0x00 as a connection error";
+inline constexpr absl::string_view kSettingsStreamIdMustBeZero =
+    "RFC9113: If an endpoint receives a SETTINGS frame whose Stream "
+    "Identifier field is anything other than 0x00, the endpoint MUST respond "
+    "with a connection error";
+
+// Frame length related errors
+inline constexpr absl::string_view kRstStreamLength4 =
+    "RFC9113: A RST_STREAM frame with a length other than 4 octets MUST be "
+    "treated as a connection error";
+inline constexpr absl::string_view kSettingsLength0 =
+    "RFC9113: Receipt of a SETTINGS frame with the ACK flag set and a length "
+    "field value other than 0 MUST be treated as a connection error";
+inline constexpr absl::string_view kSettingsLength6x =
+    "RFC9113: SETTINGS frame with a length other than a multiple of 6 octets "
+    "MUST be treated as a connection error";
+inline constexpr absl::string_view kPingLength8 =
+    "RFC9113: Receipt of a PING frame with a length field value other than 8 "
+    "MUST be treated as a connection error";
+inline constexpr absl::string_view kWindowUpdateLength4 =
+    "RFC9113: A WINDOW_UPDATE frame with a length other than 4 octets MUST be "
+    "treated as a connection error";
+inline constexpr absl::string_view kWindowSizeIncrement =
+    "RFC9113: The legal range for the increment to the flow-control window is "
+    "1 to (2^31)-1";
+inline constexpr absl::string_view kPaddingLengthLargerThanFrameLength =
+    "RFC9113: If the length of the padding is the length of the frame payload "
+    "or greater, the recipient MUST treat this as a connection error";
+
+// Misc Errors
+inline constexpr absl::string_view kNoPushPromise =
+    "RFC9113: PUSH_PROMISE MUST NOT be sent if the SETTINGS_ENABLE_PUSH "
+    "setting of the "
+    "peer endpoint is set to 0";
+
+inline constexpr absl::string_view kFrameParserIncorrectPadding =
+    "Incorrect length of padding in frame";
+inline constexpr absl::string_view kIncorrectFrame = "Incorrect Frame";
+inline constexpr absl::string_view kGoAwayLength8 =
+    "GOAWAY frame should have a Last-Stream-ID and Error Code making the "
+    "minimum length 8 octets";
+
+// TODO(tjagtap) : [PH2][P2] : Take care that our transport class does not make
+// stream id larger than this.
+inline constexpr uint32_t kMaxStreamId31Bit = 0x7fffffffu;
+
+}  // namespace RFC9113
 }  // namespace grpc_core
 
 #endif  // GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_H

src/core/ext/transport/chttp2/transport/frame_data.cc

@@ -55,6 +55,7 @@ absl::Status grpc_chttp2_data_parser_begin_frame(uint8_t flags,
 void grpc_chttp2_encode_data(uint32_t id, grpc_slice_buffer* inbuf,
                              uint32_t write_bytes, int is_eof,
                              grpc_core::CallTracerInterface* call_tracer,
+                             grpc_core::Http2ZTraceCollector* ztrace_collector,
                              grpc_slice_buffer* outbuf) {
   grpc_slice hdr;
   uint8_t* p;
@@ -74,6 +75,9 @@ void grpc_chttp2_encode_data(uint32_t id, grpc_slice_buffer* inbuf,
   *p++ = static_cast<uint8_t>(id);
   grpc_slice_buffer_add(outbuf, hdr);
 
+  ztrace_collector->Append(
+      grpc_core::H2DataTrace<false>{id, is_eof != 0, write_bytes});
+
   grpc_slice_buffer_move_first_no_ref(inbuf, write_bytes, outbuf);
 
   grpc_core::global_stats().IncrementHttp2WriteDataFrameSize(write_bytes);
@@ -148,6 +152,12 @@ grpc_error_handle grpc_chttp2_data_parser_parse(void* /*parser*/,
   grpc_slice_buffer_add(&s->frame_storage, slice);
   grpc_chttp2_maybe_complete_recv_message(t, s);
 
+  if (is_last) {
+    t->http2_ztrace_collector.Append(grpc_core::H2DataTrace<true>{
+        t->incoming_stream_id,
+        (t->incoming_frame_flags & GRPC_CHTTP2_DATA_FLAG_END_STREAM) != 0,
+        t->incoming_frame_size});
+  }
   if (is_last && s->received_last_frame) {
     grpc_chttp2_mark_stream_closed(
         t, s, true, false,

src/core/ext/transport/chttp2/transport/frame_data.h

@@ -26,6 +26,7 @@
 #include <stdint.h>
 
 #include "absl/status/status.h"
+#include "src/core/ext/transport/chttp2/transport/http2_ztrace_collector.h"
 #include "src/core/ext/transport/chttp2/transport/legacy_frame.h"
 #include "src/core/lib/iomgr/error.h"
 #include "src/core/lib/promise/poll.h"
@@ -49,6 +50,7 @@ grpc_error_handle grpc_chttp2_data_parser_parse(void* parser,
 void grpc_chttp2_encode_data(uint32_t id, grpc_slice_buffer* inbuf,
                              uint32_t write_bytes, int is_eof,
                              grpc_core::CallTracerInterface* call_tracer,
+                             grpc_core::Http2ZTraceCollector* ztrace_collector,
                              grpc_slice_buffer* outbuf);
 
 grpc_core::Poll<grpc_error_handle> grpc_deframe_unprocessed_incoming_frames(

src/core/ext/transport/chttp2/transport/frame_goaway.cc

@@ -138,6 +138,11 @@ grpc_error_handle grpc_chttp2_goaway_parser_parse(void* parser,
       p->debug_pos += static_cast<uint32_t>(end - cur);
       p->state = GRPC_CHTTP2_GOAWAY_DEBUG;
       if (is_last) {
+        t->http2_ztrace_collector.Append([p]() {
+          return grpc_core::H2GoAwayTrace<true>{
+              p->last_stream_id, p->error_code,
+              std::string(absl::string_view(p->debug_data, p->debug_length))};
+        });
         grpc_chttp2_add_incoming_goaway(
             t, p->error_code, p->last_stream_id,
             absl::string_view(p->debug_data, p->debug_length));
@@ -149,15 +154,22 @@ grpc_error_handle grpc_chttp2_goaway_parser_parse(void* parser,
   GPR_UNREACHABLE_CODE(return GRPC_ERROR_CREATE("Should never reach here"));
 }
 
-void grpc_chttp2_goaway_append(uint32_t last_stream_id, uint32_t error_code,
-                               const grpc_slice& debug_data,
-                               grpc_slice_buffer* slice_buffer) {
+void grpc_chttp2_goaway_append(
+    uint32_t last_stream_id, uint32_t error_code, const grpc_slice& debug_data,
+    grpc_slice_buffer* slice_buffer,
+    grpc_core::Http2ZTraceCollector* ztrace_collector) {
   grpc_slice header = GRPC_SLICE_MALLOC(9 + 4 + 4);
   uint8_t* p = GRPC_SLICE_START_PTR(header);
   uint32_t frame_length;
   CHECK(GRPC_SLICE_LENGTH(debug_data) < UINT32_MAX - 4 - 4);
   frame_length = 4 + 4 + static_cast<uint32_t> GRPC_SLICE_LENGTH(debug_data);
 
+  ztrace_collector->Append([last_stream_id, error_code, debug_data]() {
+    return grpc_core::H2GoAwayTrace<false>{
+        last_stream_id, error_code,
+        std::string(grpc_core::StringViewFromSlice(debug_data))};
+  });
+
   // frame header: length
   *p++ = static_cast<uint8_t>(frame_length >> 16);
   *p++ = static_cast<uint8_t>(frame_length >> 8);

src/core/ext/transport/chttp2/transport/frame_goaway.h

@@ -23,6 +23,7 @@
 #include <grpc/support/port_platform.h>
 #include <stdint.h>
 
+#include "src/core/ext/transport/chttp2/transport/http2_ztrace_collector.h"
 #include "src/core/ext/transport/chttp2/transport/legacy_frame.h"
 #include "src/core/lib/iomgr/error.h"
 
@@ -56,8 +57,9 @@ grpc_error_handle grpc_chttp2_goaway_parser_parse(void* parser,
                                                   const grpc_slice& slice,
                                                   int is_last);
 
-void grpc_chttp2_goaway_append(uint32_t last_stream_id, uint32_t error_code,
-                               const grpc_slice& debug_data,
-                               grpc_slice_buffer* slice_buffer);
+void grpc_chttp2_goaway_append(
+    uint32_t last_stream_id, uint32_t error_code, const grpc_slice& debug_data,
+    grpc_slice_buffer* slice_buffer,
+    grpc_core::Http2ZTraceCollector* ztrace_collector);
 
 #endif  // GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_GOAWAY_H

src/core/ext/transport/chttp2/transport/frame_ping.cc

@@ -90,6 +90,8 @@ grpc_error_handle grpc_chttp2_ping_parser_parse(void* parser,
 
   if (p->byte == 8) {
     CHECK(is_last);
+    t->http2_ztrace_collector.Append(
+        grpc_core::H2PingTrace<true>{p->is_ack != 0, p->opaque_8bytes});
     if (p->is_ack) {
       GRPC_TRACE_LOG(http2_ping, INFO)
           << (t->is_client ? "CLIENT" : "SERVER") << "[" << t

src/core/ext/transport/chttp2/transport/frame_rst_stream.cc

@@ -36,17 +36,20 @@
 #include "src/core/ext/transport/chttp2/transport/ping_callbacks.h"
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/experiments/experiments.h"
+#include "src/core/util/shared_bit_gen.h"
 #include "src/core/util/status_helper.h"
 
 using grpc_core::http2::Http2ErrorCode;
 
 grpc_slice grpc_chttp2_rst_stream_create(
-    uint32_t id, uint32_t code, grpc_core::CallTracerInterface* call_tracer) {
+    uint32_t id, uint32_t code, grpc_core::CallTracerInterface* call_tracer,
+    grpc_core::Http2ZTraceCollector* ztrace_collector) {
   static const size_t frame_size = 13;
   grpc_slice slice = GRPC_SLICE_MALLOC(frame_size);
   if (call_tracer != nullptr) {
     call_tracer->RecordOutgoingBytes({frame_size, 0, 0});
   }
+  ztrace_collector->Append(grpc_core::H2RstStreamTrace<false>{id, code});
   uint8_t* p = GRPC_SLICE_START_PTR(slice);
 
   // Frame size.
@@ -75,8 +78,9 @@ void grpc_chttp2_add_rst_stream_to_next_write(
     grpc_chttp2_transport* t, uint32_t id, uint32_t code,
     grpc_core::CallTracerInterface* call_tracer) {
   t->num_pending_induced_frames++;
-  grpc_slice_buffer_add(&t->qbuf,
-                        grpc_chttp2_rst_stream_create(id, code, call_tracer));
+  grpc_slice_buffer_add(
+      &t->qbuf, grpc_chttp2_rst_stream_create(id, code, call_tracer,
+                                              &t->http2_ztrace_collector));
 }
 
 grpc_error_handle grpc_chttp2_rst_stream_parser_begin_frame(
@@ -114,6 +118,8 @@ grpc_error_handle grpc_chttp2_rst_stream_parser_parse(void* parser,
                       ((static_cast<uint32_t>(p->reason_bytes[1])) << 16) |
                       ((static_cast<uint32_t>(p->reason_bytes[2])) << 8) |
                       ((static_cast<uint32_t>(p->reason_bytes[3])));
+    t->http2_ztrace_collector.Append(
+        grpc_core::H2RstStreamTrace<true>{t->incoming_stream_id, reason});
     GRPC_TRACE_LOG(http, INFO)
         << "[chttp2 transport=" << t << " stream=" << s
         << "] received RST_STREAM(reason=" << reason << ")";
@@ -128,8 +134,9 @@ grpc_error_handle grpc_chttp2_rst_stream_parser_parse(void* parser,
           grpc_core::StatusIntProperty::kHttp2Error,
           static_cast<intptr_t>(reason));
     }
+    grpc_core::SharedBitGen g;
     if (!t->is_client &&
-        absl::Bernoulli(t->bitgen, t->ping_on_rst_stream_percent / 100.0)) {
+        absl::Bernoulli(g, t->ping_on_rst_stream_percent / 100.0)) {
       ++t->num_pending_induced_frames;
       t->ping_callbacks.RequestPing();
       grpc_chttp2_initiate_write(t, GRPC_CHTTP2_INITIATE_WRITE_KEEPALIVE_PING);

src/core/ext/transport/chttp2/transport/frame_rst_stream.h

@@ -23,6 +23,7 @@
 #include <grpc/support/port_platform.h>
 #include <stdint.h>
 
+#include "src/core/ext/transport/chttp2/transport/http2_ztrace_collector.h"
 #include "src/core/ext/transport/chttp2/transport/legacy_frame.h"
 #include "src/core/lib/iomgr/error.h"
 #include "src/core/lib/transport/transport.h"
@@ -34,7 +35,8 @@ struct grpc_chttp2_rst_stream_parser {
 };
 grpc_slice grpc_chttp2_rst_stream_create(
     uint32_t stream_id, uint32_t code,
-    grpc_core::CallTracerInterface* call_tracer);
+    grpc_core::CallTracerInterface* call_tracer,
+    grpc_core::Http2ZTraceCollector* ztrace_collector);
 
 // Adds RST_STREAM frame to t->qbuf (buffer for the next write). Should be
 // called when we want to add RST_STREAM and we are not in

src/core/ext/transport/chttp2/transport/frame_settings.cc

@@ -31,6 +31,7 @@
 #include "src/core/ext/transport/chttp2/transport/flow_control.h"
 #include "src/core/ext/transport/chttp2/transport/frame_goaway.h"
 #include "src/core/ext/transport/chttp2/transport/http2_settings.h"
+#include "src/core/ext/transport/chttp2/transport/http2_ztrace_collector.h"
 #include "src/core/ext/transport/chttp2/transport/internal.h"
 #include "src/core/ext/transport/chttp2/transport/legacy_frame.h"
 #include "src/core/lib/debug/trace.h"
@@ -94,6 +95,8 @@ grpc_error_handle grpc_chttp2_settings_parser_parse(void* p,
   const uint8_t* end = GRPC_SLICE_END_PTR(slice);
 
   if (parser->is_ack) {
+    t->http2_ztrace_collector.Append(
+        grpc_core::H2SettingsTrace<true>{true, {}});
     return absl::OkStatus();
   }
 
@@ -118,6 +121,20 @@ grpc_error_handle grpc_chttp2_settings_parser_parse(void* p,
             grpc_core::global_stats()
                 .IncrementHttp2PreferredReceiveCryptoMessageSize(
                     target_settings->preferred_receive_crypto_message_size());
+            t->http2_ztrace_collector.Append([parser]() {
+              grpc_core::H2SettingsTrace<true> settings{false, {}};
+              // TODO(ctiller): produce actual wire settings here, not a
+              // diff. Likely this needs to wait for PH2 where we separate
+              // the parse loop from the application loop.
+              parser->incoming_settings->Diff(
+                  false, *parser->target_settings,
+                  [&settings](uint16_t key, uint32_t value) {
+                    settings.settings.push_back({key, value});
+                  });
+              return settings;
+            });
+            t->http2_ztrace_collector.Append(
+                []() { return grpc_core::H2SettingsTrace<false>{true, {}}; });
             *parser->target_settings = *parser->incoming_settings;
             t->num_pending_induced_frames++;
             grpc_slice_buffer_add(&t->qbuf, grpc_chttp2_settings_ack_create());
@@ -198,7 +215,8 @@ grpc_error_handle grpc_chttp2_settings_parser_parse(void* p,
         if (error != Http2ErrorCode::kNoError) {
           grpc_chttp2_goaway_append(
               t->last_new_stream_id, static_cast<uint32_t>(error),
-              grpc_slice_from_static_string("HTTP2 settings error"), &t->qbuf);
+              grpc_slice_from_static_string("HTTP2 settings error"), &t->qbuf,
+              &t->http2_ztrace_collector);
           return GRPC_ERROR_CREATE(absl::StrFormat(
               "invalid value %u passed for %s", parser->value,
               grpc_core::Http2Settings::WireIdToName(parser->id).c_str()));

src/core/ext/transport/chttp2/transport/frame_window_update.cc

@@ -27,6 +27,7 @@
 #include "absl/strings/str_format.h"
 #include "src/core/ext/transport/chttp2/transport/call_tracer_wrapper.h"
 #include "src/core/ext/transport/chttp2/transport/flow_control.h"
+#include "src/core/ext/transport/chttp2/transport/http2_ztrace_collector.h"
 #include "src/core/ext/transport/chttp2/transport/internal.h"
 #include "src/core/ext/transport/chttp2/transport/stream_lists.h"
 #include "src/core/telemetry/stats.h"
@@ -101,6 +102,9 @@ grpc_error_handle grpc_chttp2_window_update_parser_parse(
     }
     CHECK(is_last);
 
+    t->http2_ztrace_collector.Append(grpc_core::H2WindowUpdateTrace<true>{
+        t->incoming_stream_id, received_update});
+
     if (t->incoming_stream_id != 0) {
       if (s != nullptr) {
         grpc_core::Timestamp now = grpc_core::Timestamp::Now();

src/core/ext/transport/chttp2/transport/hpack_encoder.cc

@@ -101,6 +101,13 @@ void HPackCompressor::Frame(const EncodeHeaderOptions& options,
     FillHeader(grpc_slice_buffer_tiny_add(output, kHeadersFrameHeaderSize),
                frame_type, options.stream_id, len, flags);
     options.call_tracer->RecordOutgoingBytes({kHeadersFrameHeaderSize, 0, 0});
+    options.ztrace_collector->Append([&]() {
+      return H2HeaderTrace<false>{
+          options.stream_id, (flags & GRPC_CHTTP2_DATA_FLAG_END_HEADERS) != 0,
+          (flags & GRPC_CHTTP2_DATA_FLAG_END_STREAM) != 0,
+          frame_type == GRPC_CHTTP2_FRAME_CONTINUATION,
+          static_cast<uint32_t>(len)};
+    });
     grpc_slice_buffer_move_first(raw.c_slice_buffer(), len, output);
 
     frame_type = GRPC_CHTTP2_FRAME_CONTINUATION;

src/core/ext/transport/chttp2/transport/hpack_encoder.h

@@ -35,6 +35,7 @@
 #include "src/core/call/metadata_compression_traits.h"
 #include "src/core/ext/transport/chttp2/transport/hpack_constants.h"
 #include "src/core/ext/transport/chttp2/transport/hpack_encoder_table.h"
+#include "src/core/ext/transport/chttp2/transport/http2_ztrace_collector.h"
 #include "src/core/lib/slice/slice.h"
 #include "src/core/lib/slice/slice_buffer.h"
 #include "src/core/lib/transport/timeout_encoding.h"
@@ -353,6 +354,7 @@ class HPackCompressor {
     bool use_true_binary_metadata;
     size_t max_frame_size;
     CallTracerInterface* call_tracer;
+    Http2ZTraceCollector* ztrace_collector;
   };
 
   template <typename HeaderSet>

src/core/ext/transport/chttp2/transport/http2_settings.h

@@ -27,6 +27,7 @@
 #include "absl/strings/string_view.h"
 #include "src/core/ext/transport/chttp2/transport/frame.h"
 #include "src/core/ext/transport/chttp2/transport/http2_status.h"
+#include "src/core/util/json/json.h"
 #include "src/core/util/useful.h"
 
 namespace grpc_core {
@@ -132,6 +133,22 @@ class Http2Settings {
 
   bool operator!=(const Http2Settings& rhs) const { return !operator==(rhs); }
 
+  Json::Object ToJsonObject() const {
+    Json::Object object;
+    object["headerTableSize"] = Json::FromNumber(header_table_size());
+    object["maxConcurrentStreams"] = Json::FromNumber(max_concurrent_streams());
+    object["initialWindowSize"] = Json::FromNumber(initial_window_size());
+    object["maxFrameSize"] = Json::FromNumber(max_frame_size());
+    object["maxHeaderListSize"] = Json::FromNumber(max_header_list_size());
+    object["preferredReceiveCryptoMessageSize"] =
+        Json::FromNumber(preferred_receive_crypto_message_size());
+    object["enablePush"] = Json::FromBool(enable_push());
+    object["allowTrueBinaryMetadata"] =
+        Json::FromBool(allow_true_binary_metadata());
+    object["allowSecurityFrame"] = Json::FromBool(allow_security_frame());
+    return object;
+  }
+
  private:
   uint32_t header_table_size_ = 4096;
   uint32_t max_concurrent_streams_ = 4294967295u;
@@ -152,6 +169,15 @@ class Http2SettingsManager {
   Http2Settings& mutable_peer() { return peer_; }
   const Http2Settings& peer() const { return peer_; }
 
+  Json::Object ToJsonObject() const {
+    Json::Object object;
+    object["local"] = Json::FromObject(local_.ToJsonObject());
+    object["sent"] = Json::FromObject(sent_.ToJsonObject());
+    object["peer"] = Json::FromObject(peer_.ToJsonObject());
+    object["acked"] = Json::FromObject(acked_.ToJsonObject());
+    return object;
+  }
+
   std::optional<Http2SettingsFrame> MaybeSendUpdate();
   GRPC_MUST_USE_RESULT bool AckLastSend();
 

src/core/ext/transport/chttp2/transport/http2_status.h

@@ -19,13 +19,21 @@
 #ifndef GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HTTP2_STATUS_H
 #define GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HTTP2_STATUS_H
 
+#include <grpc/support/port_platform.h>
+
+#include <cstdint>
+#include <string>
+#include <variant>
+
 #include "absl/log/check.h"
 #include "absl/status/status.h"
-#include "absl/strings/string_view.h"
+#include "absl/strings/str_cat.h"
+#include "src/core/util/time.h"
 
 namespace grpc_core {
 namespace http2 {
 
+// These error codes are as per RFC9113
 // https://www.rfc-editor.org/rfc/rfc9113.html#name-error-codes
 // The RFC tells us to use 32 bit, but since this is our internal
 // representation, we can use a smaller value.
@@ -46,6 +54,355 @@ enum class Http2ErrorCode : uint8_t {
   kDoNotUse = 0xffu  // Force use of a default clause
 };
 
+inline absl::StatusCode ErrorCodeToAbslStatusCode(
+    const Http2ErrorCode http2_code,
+    const Timestamp deadline = Timestamp::InfFuture()) {
+  switch (http2_code) {
+    case Http2ErrorCode::kNoError:
+      return absl::StatusCode::kOk;
+    case Http2ErrorCode::kEnhanceYourCalm:
+      return absl::StatusCode::kResourceExhausted;
+    case Http2ErrorCode::kInadequateSecurity:
+      return absl::StatusCode::kPermissionDenied;
+    case Http2ErrorCode::kRefusedStream:
+      return absl::StatusCode::kUnavailable;
+    case Http2ErrorCode::kCancel:
+      return (Timestamp::Now() > deadline) ? absl::StatusCode::kDeadlineExceeded
+                                           : absl::StatusCode::kCancelled;
+    default:
+      return absl::StatusCode::kInternal;
+  }
+  GPR_UNREACHABLE_CODE(return absl::StatusCode::kUnknown);
+}
+
+inline Http2ErrorCode AbslStatusCodeToErrorCode(const absl::StatusCode status) {
+  switch (status) {
+    case absl::StatusCode::kOk:
+      return Http2ErrorCode::kNoError;
+    case absl::StatusCode::kCancelled:
+      return Http2ErrorCode::kCancel;
+    case absl::StatusCode::kDeadlineExceeded:
+      return Http2ErrorCode::kCancel;
+    case absl::StatusCode::kResourceExhausted:
+      return Http2ErrorCode::kEnhanceYourCalm;
+    case absl::StatusCode::kPermissionDenied:
+      return Http2ErrorCode::kInadequateSecurity;
+    case absl::StatusCode::kUnavailable:
+      return Http2ErrorCode::kRefusedStream;
+    default:
+      return Http2ErrorCode::kInternalError;
+  };
+}
+
+class GRPC_MUST_USE_RESULT Http2Status {
+ public:
+  // Classifying if an error is a stream error or a connection Http2Status must
+  // be done at the time of error object creation. Once the Http2Status object
+  // is created, its Http2ErrorType is immutable. This is intentional.
+  enum class Http2ErrorType : uint8_t {
+    kOk = 0x0,
+    kConnectionError = 0x1,
+    kStreamError = 0x2,
+  };
+
+  static Http2Status Ok() { return Http2Status(); }
+
+  // To pass message :
+  // Either pass a absl::string_view which is then copied into a std::string.
+  // Or, pass a local std::string using std::move
+  static Http2Status Http2ConnectionError(const Http2ErrorCode error_code,
+                                          std::string message) {
+    return Http2Status(error_code, Http2ErrorType::kConnectionError, message);
+  }
+
+  static Http2Status Http2StreamError(const Http2ErrorCode error_code,
+                                      std::string message) {
+    return Http2Status(error_code, Http2ErrorType::kStreamError, message);
+  }
+
+  static Http2Status AbslConnectionError(const absl::StatusCode code,
+                                         std::string message) {
+    return Http2Status(code, Http2ErrorType::kConnectionError, message);
+  }
+
+  static Http2Status AbslStreamError(const absl::StatusCode code,
+                                     std::string message) {
+    return Http2Status(code, Http2ErrorType::kStreamError, message);
+  }
+
+  GRPC_MUST_USE_RESULT Http2ErrorType GetType() const { return error_type_; }
+
+  // We only expect to use this in 2 places
+  // 1. To know what error code to send in a HTTP2 GOAWAY frame.
+  // 2. In tests
+  // Any other usage is strongly discouraged.
+  GRPC_MUST_USE_RESULT Http2ErrorCode GetConnectionErrorCode() const {
+    switch (error_type_) {
+      case Http2ErrorType::kOk:
+        CHECK(false);
+      case Http2ErrorType::kConnectionError:
+        return http2_code_;
+      case Http2ErrorType::kStreamError:
+        CHECK(false);
+      default:
+        CHECK(false);
+    }
+    GPR_UNREACHABLE_CODE(return http2_code_);
+  }
+
+  // We only expect to use this in 2 places
+  // 1. To know what error code to send in a HTTP2 RST_STREAM.
+  // 2. In tests
+  // Any other usage is strongly discouraged.
+  GRPC_MUST_USE_RESULT Http2ErrorCode GetStreamErrorCode() const {
+    switch (error_type_) {
+      case Http2ErrorType::kOk:
+        CHECK(false);
+      case Http2ErrorType::kConnectionError:
+        CHECK(false);
+      case Http2ErrorType::kStreamError:
+        return http2_code_;
+      default:
+        CHECK(false);
+    }
+    GPR_UNREACHABLE_CODE(return http2_code_);
+  }
+
+  // If an error code needs to be used along with promises, or passed out of the
+  // transport, this function should be used.
+  GRPC_MUST_USE_RESULT absl::Status GetAbslConnectionError() const {
+    switch (error_type_) {
+      case Http2ErrorType::kOk:
+        CHECK(false);
+      case Http2ErrorType::kConnectionError:
+        return AbslError();
+      case Http2ErrorType::kStreamError:
+        CHECK(false);
+      default:
+        CHECK(false);
+    }
+    GPR_UNREACHABLE_CODE(return absl::OkStatus());
+  }
+
+  // If an error code needs to be used along with promises, or passed out of the
+  // transport, this function should be used.
+  GRPC_MUST_USE_RESULT absl::Status GetAbslStreamError() const {
+    switch (error_type_) {
+      case Http2ErrorType::kOk:
+        CHECK(false);
+      case Http2ErrorType::kConnectionError:
+        CHECK(false);
+      case Http2ErrorType::kStreamError:
+        return AbslError();
+      default:
+        CHECK(false);
+    }
+    GPR_UNREACHABLE_CODE(return absl::OkStatus());
+  }
+
+  bool IsOk() const { return (http2_code_ == Http2ErrorCode::kNoError); }
+
+  std::string DebugString() const {
+    return absl::StrCat(DebugGetType(), ": {Error Code:", DebugGetCode(),
+                        ", Message:", message_, "}");
+  }
+
+  ~Http2Status() = default;
+
+  template <typename Sink>
+  friend void AbslStringify(Sink& sink, const Http2Status& frame) {
+    sink.Append(frame.DebugString());
+  }
+
+  Http2Status(Http2Status&& move_status) = default;
+
+  // Our http2_code_ code is a const, which makes an assignment illegal.
+  Http2Status& operator=(Http2Status&& rhs) = delete;
+
+  Http2Status(const Http2Status&) = delete;
+  Http2Status& operator=(const Http2Status&) = delete;
+
+ private:
+  explicit Http2Status()
+      : http2_code_(Http2ErrorCode::kNoError),
+        error_type_(Http2ErrorType::kOk),
+        absl_code_(absl::StatusCode::kOk) {
+    Validate();
+  }
+
+  explicit Http2Status(const absl::StatusCode code, const Http2ErrorType type,
+                       std::string& message)
+      : http2_code_((code == absl::StatusCode::kOk)
+                        ? Http2ErrorCode::kNoError
+                        : Http2ErrorCode::kInternalError),
+        error_type_(type),
+        absl_code_(code),
+        message_(std::move(message)) {
+    Validate();
+  }
+
+  explicit Http2Status(const Http2ErrorCode code, const Http2ErrorType type,
+                       std::string& message)
+      : http2_code_(code),
+        error_type_(type),
+        absl_code_(ErrorCodeToAbslStatusCode(http2_code_)),
+        message_(std::move(message)) {
+    Validate();
+  }
+
+  absl::Status AbslError() const {
+    if (IsOk()) return absl::OkStatus();
+    return absl::Status(absl_code_, message_);
+  }
+
+  void Validate() const {
+    DCHECK((http2_code_ == Http2ErrorCode::kNoError &&
+            error_type_ == Http2ErrorType::kOk &&
+            absl_code_ == absl::StatusCode::kOk) ||
+           (http2_code_ > Http2ErrorCode::kNoError &&
+            error_type_ > Http2ErrorType::kOk &&
+            absl_code_ != absl::StatusCode::kOk));
+    DCHECK((IsOk() && message_.empty()) || (!IsOk() && !message_.empty()));
+  }
+
+  std::string DebugGetType() const {
+    switch (error_type_) {
+      case Http2ErrorType::kOk:
+        return "Ok";
+      case Http2ErrorType::kConnectionError:
+        return "Connection Error";
+      case Http2ErrorType::kStreamError:
+        return "Stream Error";
+      default:
+        DCHECK(false);
+    }
+    GPR_UNREACHABLE_CODE(return "Invalid");
+  }
+
+  std::string DebugGetCode() const {
+    switch (http2_code_) {
+      case Http2ErrorCode::kNoError:
+        return "NO_ERROR";
+      case Http2ErrorCode::kProtocolError:
+        return "PROTOCOL_ERROR";
+      case Http2ErrorCode::kInternalError:
+        return "INTERNAL_ERROR";
+      case Http2ErrorCode::kFlowControlError:
+        return "FLOW_CONTROL_ERROR";
+      case Http2ErrorCode::kSettingsTimeout:
+        return "SETTINGS_TIMEOUT";
+      case Http2ErrorCode::kStreamClosed:
+        return "STREAM_CLOSED";
+      case Http2ErrorCode::kFrameSizeError:
+        return "FRAME_SIZE_ERROR";
+      case Http2ErrorCode::kRefusedStream:
+        return "REFUSED_STREAM";
+      case Http2ErrorCode::kCancel:
+        return "CANCEL";
+      case Http2ErrorCode::kCompressionError:
+        return "COMPRESSION_ERROR";
+      case Http2ErrorCode::kConnectError:
+        return "CONNECT_ERROR";
+      case Http2ErrorCode::kEnhanceYourCalm:
+        return "ENHANCE_YOUR_CALM";
+      case Http2ErrorCode::kInadequateSecurity:
+        return "INADEQUATE_SECURITY";
+      case Http2ErrorCode::kDoNotUse:
+        return "HTTP_1_1_REQUIRED";
+      default:
+        DCHECK(false);
+    }
+    GPR_UNREACHABLE_CODE(return "Invalid");
+  }
+
+  const Http2ErrorCode http2_code_;
+  const Http2ErrorType error_type_;
+  const absl::StatusCode absl_code_;
+
+  std::string message_;
+};
+
+// We can add more methods and helpers as needed.
+// This class is similar to ValueOrFailure but a more minamilasit version.
+// Reference :
+// https://github.com/grpc/grpc/blob/master/src/core/lib/promise/status_flag.h
+
+// A value if an operation was successful, or a Http2Status if not.
+template <typename T>
+class GRPC_MUST_USE_RESULT ValueOrHttp2Status {
+ public:
+  // NOLINTNEXTLINE(google-explicit-constructor)
+  ValueOrHttp2Status(T value) : value_(std::move(value)) {
+    DCHECK(std::holds_alternative<T>(value_));
+  }
+
+  // NOLINTNEXTLINE(google-explicit-constructor)
+  ValueOrHttp2Status(Http2Status status) : value_(std::move(status)) {
+    DCHECK(std::holds_alternative<Http2Status>(value_));
+    CHECK(std::get<Http2Status>(value_).GetType() !=
+          Http2Status::Http2ErrorType::kOk);
+  }
+
+  GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION const T& value() const {
+    DCHECK(std::holds_alternative<T>(value_));
+    return std::get<T>(value_);
+  }
+
+  GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION T& value() {
+    DCHECK(std::holds_alternative<T>(value_));
+    return std::get<T>(value_);
+  }
+
+  GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION static Http2Status TakeStatus(
+      ValueOrHttp2Status<T>&& status) {
+    DCHECK(std::holds_alternative<Http2Status>(status.value_));
+    return std::move(std::get<Http2Status>(status.value_));
+  }
+
+  GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION bool IsOk() const {
+    return std::holds_alternative<T>(value_);
+  }
+
+  GRPC_MUST_USE_RESULT Http2Status::Http2ErrorType GetErrorType() const {
+    DCHECK(std::holds_alternative<Http2Status>(value_));
+    return std::get<Http2Status>(value_).GetType();
+  }
+
+  GRPC_MUST_USE_RESULT Http2ErrorCode GetConnectionErrorCode() const {
+    DCHECK(std::holds_alternative<Http2Status>(value_));
+    return std::get<Http2Status>(value_).GetConnectionErrorCode();
+  }
+
+  GRPC_MUST_USE_RESULT Http2ErrorCode GetStreamErrorCode() const {
+    DCHECK(std::holds_alternative<Http2Status>(value_));
+    return std::get<Http2Status>(value_).GetStreamErrorCode();
+  }
+
+  GRPC_MUST_USE_RESULT absl::Status GetAbslConnectionError() const {
+    DCHECK(std::holds_alternative<Http2Status>(value_));
+    return std::get<Http2Status>(value_).GetAbslConnectionError();
+  }
+
+  GRPC_MUST_USE_RESULT absl::Status GetAbslStreamError() const {
+    DCHECK(std::holds_alternative<Http2Status>(value_));
+    return std::get<Http2Status>(value_).GetAbslStreamError();
+  }
+
+  std::string DebugString() const {
+    DCHECK(std::holds_alternative<Http2Status>(value_));
+    return std::get<Http2Status>(value_).DebugString();
+  }
+
+ private:
+  std::variant<T, Http2Status> value_;
+};
+
+template <typename T>
+GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION inline T TakeValue(
+    ValueOrHttp2Status<T>&& value) {
+  return std::move(value.value());
+}
+
 }  // namespace http2
 }  // namespace grpc_core
 

src/core/ext/transport/chttp2/transport/http2_ztrace_collector.h

@@ -0,0 +1,252 @@
+// Copyright 2025 The gRPC Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HTTP2_ZTRACE_COLLECTOR_H
+#define GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HTTP2_ZTRACE_COLLECTOR_H
+
+#include <cstdint>
+#include <map>
+#include <string>
+
+#include "src/core/channelz/ztrace_collector.h"
+#include "src/core/ext/transport/chttp2/transport/frame.h"
+
+namespace grpc_core {
+namespace http2_ztrace_collector_detail {
+
+class Config {
+ public:
+  explicit Config(std::map<std::string, std::string>) {}
+
+  template <typename T>
+  bool Finishes(const T&) {
+    return false;
+  }
+};
+
+}  // namespace http2_ztrace_collector_detail
+
+template <bool kRead>
+struct H2DataTrace {
+  uint32_t stream_id;
+  bool end_stream;
+  uint32_t payload_length;
+
+  size_t MemoryUsage() const { return sizeof(*this); }
+
+  void RenderJson(Json::Object& json) const {
+    json["read"] = Json::FromBool(kRead);
+    json["frame_type"] = Json::FromString("DATA");
+    json["stream_id"] = Json::FromNumber(stream_id);
+    json["end_stream"] = Json::FromBool(end_stream);
+    json["payload_length"] = Json::FromNumber(payload_length);
+  }
+};
+
+template <bool kRead>
+struct H2HeaderTrace {
+  uint32_t stream_id;
+  bool end_headers;
+  bool end_stream;
+  bool continuation;
+  uint32_t payload_length;
+
+  size_t MemoryUsage() const { return sizeof(*this); }
+
+  void RenderJson(Json::Object& json) const {
+    json["read"] = Json::FromBool(kRead);
+    json["frame_type"] = continuation ? Json::FromString("CONTINUATION")
+                                      : Json::FromString("HEADERS");
+    json["stream_id"] = Json::FromNumber(stream_id);
+    json["end_headers"] = Json::FromBool(end_headers);
+    json["end_stream"] = Json::FromBool(end_stream);
+    json["payload_length"] = Json::FromNumber(payload_length);
+  }
+};
+
+template <bool kRead>
+struct H2RstStreamTrace {
+  uint32_t stream_id;
+  uint32_t error_code;
+
+  size_t MemoryUsage() const { return sizeof(*this); }
+
+  void RenderJson(Json::Object& json) const {
+    json["read"] = Json::FromBool(kRead);
+    json["frame_type"] = Json::FromString("RST_STREAM");
+    json["stream_id"] = Json::FromNumber(stream_id);
+    json["error_code"] = Json::FromNumber(error_code);
+  }
+};
+
+template <bool kRead>
+struct H2SettingsTrace {
+  bool ack;
+  std::vector<Http2SettingsFrame::Setting> settings;
+
+  size_t MemoryUsage() const {
+    return sizeof(*this) +
+           sizeof(Http2SettingsFrame::Setting) * settings.size();
+  }
+
+  void RenderJson(Json::Object& json) const {
+    json["read"] = Json::FromBool(kRead);
+    json["frame_type"] = Json::FromString("SETTINGS");
+    json["ack"] = Json::FromBool(ack);
+    Json::Array settings_array;
+    for (const auto& setting : settings) {
+      Json::Object setting_object;
+      setting_object["id"] = Json::FromNumber(setting.id);
+      setting_object["value"] = Json::FromNumber(setting.value);
+      settings_array.push_back(Json::FromObject(std::move(setting_object)));
+    }
+    json["settings"] = Json::FromArray(std::move(settings_array));
+  }
+};
+
+template <bool kRead>
+struct H2PingTrace {
+  bool ack;
+  uint64_t opaque;
+
+  size_t MemoryUsage() const { return sizeof(*this); }
+
+  void RenderJson(Json::Object& json) const {
+    json["read"] = Json::FromBool(kRead);
+    json["frame_type"] = Json::FromString("PING");
+    json["ack"] = Json::FromBool(ack);
+    json["opaque"] = Json::FromNumber(opaque);
+  }
+};
+
+template <bool kRead>
+struct H2GoAwayTrace {
+  uint32_t last_stream_id;
+  uint32_t error_code;
+  std::string debug_data;
+
+  size_t MemoryUsage() const { return sizeof(*this) + debug_data.size(); }
+
+  void RenderJson(Json::Object& json) const {
+    json["read"] = Json::FromBool(kRead);
+    json["frame_type"] = Json::FromString("GOAWAY");
+    json["last_stream_id"] = Json::FromNumber(last_stream_id);
+    json["error_code"] = Json::FromNumber(error_code);
+    json["debug_data"] = Json::FromString(debug_data);
+  }
+};
+
+template <bool kRead>
+struct H2WindowUpdateTrace {
+  uint32_t stream_id;
+  uint32_t window_size_increment;
+
+  size_t MemoryUsage() const { return sizeof(*this); }
+
+  void RenderJson(Json::Object& json) const {
+    json["read"] = Json::FromBool(kRead);
+    json["frame_type"] = Json::FromString("WINDOW_UPDATE");
+    json["stream_id"] = Json::FromNumber(stream_id);
+    json["window_size_increment"] = Json::FromNumber(window_size_increment);
+  }
+};
+
+template <bool kRead>
+struct H2SecurityTrace {
+  uint32_t payload_length;
+
+  size_t MemoryUsage() const { return sizeof(*this); }
+
+  void RenderJson(Json::Object& json) const {
+    json["read"] = Json::FromBool(kRead);
+    json["frame_type"] = Json::FromString("SECURITY");
+    json["payload_length"] = Json::FromNumber(payload_length);
+  }
+};
+
+struct H2UnknownFrameTrace {
+  uint8_t type;
+  uint8_t flags;
+  uint32_t stream_id;
+  uint32_t payload_length;
+
+  size_t MemoryUsage() const { return sizeof(*this); }
+
+  void RenderJson(Json::Object& json) const {
+    json["frame_type"] = Json::FromString("UNKNOWN");
+    json["type"] = Json::FromNumber(type);
+    json["flags"] = Json::FromNumber(flags);
+    json["stream_id"] = Json::FromNumber(stream_id);
+    json["payload_length"] = Json::FromNumber(payload_length);
+  }
+};
+
+struct H2FlowControlStall {
+  int64_t transport_window;
+  int64_t stream_window;
+  uint32_t stream_id;
+
+  size_t MemoryUsage() const { return sizeof(*this); }
+
+  void RenderJson(Json::Object& json) const {
+    json["metadata_type"] = Json::FromString("FLOW_CONTROL_STALL");
+    json["transport_window"] = Json::FromNumber(transport_window);
+    json["stream_window"] = Json::FromNumber(stream_window);
+    json["stream_id"] = Json::FromNumber(stream_id);
+  }
+};
+
+struct H2BeginWriteCycle {
+  uint32_t target_size;
+
+  size_t MemoryUsage() const { return sizeof(*this); }
+
+  void RenderJson(Json::Object& json) const {
+    json["metadata_type"] = Json::FromString("BEGIN_WRITE_CYCLE");
+    json["target_size"] = Json::FromNumber(target_size);
+  }
+};
+
+struct H2BeginEndpointWrite {
+  uint32_t write_size;
+
+  size_t MemoryUsage() const { return sizeof(*this); }
+
+  void RenderJson(Json::Object& json) const {
+    json["metadata_type"] = Json::FromString("BEGIN_ENDPOINT_WRITE");
+    json["write_size"] = Json::FromNumber(write_size);
+  }
+};
+
+struct H2EndWriteCycle {
+  size_t MemoryUsage() const { return sizeof(*this); }
+
+  void RenderJson(Json::Object& json) const {
+    json["metadata_type"] = Json::FromString("END_WRITE_CYCLE");
+  }
+};
+
+using Http2ZTraceCollector = channelz::ZTraceCollector<
+    http2_ztrace_collector_detail::Config, H2DataTrace<false>,
+    H2HeaderTrace<false>, H2RstStreamTrace<false>, H2SettingsTrace<false>,
+    H2PingTrace<false>, H2GoAwayTrace<false>, H2WindowUpdateTrace<false>,
+    H2SecurityTrace<false>, H2DataTrace<true>, H2HeaderTrace<true>,
+    H2RstStreamTrace<true>, H2SettingsTrace<true>, H2PingTrace<true>,
+    H2GoAwayTrace<true>, H2WindowUpdateTrace<true>, H2SecurityTrace<true>,
+    H2UnknownFrameTrace, H2FlowControlStall, H2BeginWriteCycle, H2EndWriteCycle,
+    H2BeginEndpointWrite>;
+
+}  // namespace grpc_core
+
+#endif  // GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HTTP2_ZTRACE_COLLECTOR_H

src/core/ext/transport/chttp2/transport/internal.h

@@ -41,7 +41,6 @@
 #include "src/core/call/metadata_batch.h"
 #include "src/core/channelz/channelz.h"
 #include "src/core/ext/transport/chttp2/transport/call_tracer_wrapper.h"
-#include "src/core/ext/transport/chttp2/transport/context_list_entry.h"
 #include "src/core/ext/transport/chttp2/transport/flow_control.h"
 #include "src/core/ext/transport/chttp2/transport/frame_goaway.h"
 #include "src/core/ext/transport/chttp2/transport/frame_ping.h"
@@ -52,6 +51,8 @@
 #include "src/core/ext/transport/chttp2/transport/hpack_encoder.h"
 #include "src/core/ext/transport/chttp2/transport/hpack_parser.h"
 #include "src/core/ext/transport/chttp2/transport/http2_settings.h"
+#include "src/core/ext/transport/chttp2/transport/http2_ztrace_collector.h"
+#include "src/core/ext/transport/chttp2/transport/internal_channel_arg_names.h"
 #include "src/core/ext/transport/chttp2/transport/legacy_frame.h"
 #include "src/core/ext/transport/chttp2/transport/ping_abuse_policy.h"
 #include "src/core/ext/transport/chttp2/transport/ping_callbacks.h"
@@ -73,6 +74,8 @@
 #include "src/core/lib/transport/transport.h"
 #include "src/core/lib/transport/transport_framing_endpoint_extension.h"
 #include "src/core/telemetry/call_tracer.h"
+#include "src/core/telemetry/context_list_entry.h"
+#include "src/core/telemetry/stats.h"
 #include "src/core/util/bitset.h"
 #include "src/core/util/debug_location.h"
 #include "src/core/util/ref_counted.h"
@@ -229,6 +232,21 @@ struct grpc_chttp2_transport final : public grpc_core::FilterStackTransport,
                         bool is_client);
   ~grpc_chttp2_transport() override;
 
+  class ChannelzDataSource final : public grpc_core::channelz::DataSource {
+   public:
+    explicit ChannelzDataSource(grpc_chttp2_transport* transport)
+        : grpc_core::channelz::DataSource(transport->channelz_socket),
+          transport_(transport) {}
+    ~ChannelzDataSource() { ResetDataSource(); }
+
+    void AddData(grpc_core::channelz::DataSink& sink) override;
+    std::unique_ptr<grpc_core::channelz::ZTrace> GetZTrace(
+        absl::string_view name) override;
+
+   private:
+    grpc_chttp2_transport* transport_;
+  };
+
   void Orphan() override;
 
   grpc_core::RefCountedPtr<grpc_chttp2_transport> Ref() {
@@ -250,6 +268,10 @@ struct grpc_chttp2_transport final : public grpc_core::FilterStackTransport,
   grpc_core::ServerTransport* server_transport() override { return nullptr; }
 
   absl::string_view GetTransportName() const override;
+  grpc_core::RefCountedPtr<grpc_core::channelz::SocketNode> GetSocketNode()
+      const override {
+    return channelz_socket;
+  }
   void InitStream(grpc_stream* gs, grpc_stream_refcount* refcount,
                   const void* server_data, grpc_core::Arena* arena) override;
   void SetPollset(grpc_stream* stream, grpc_pollset* pollset) override;
@@ -275,7 +297,6 @@ struct grpc_chttp2_transport final : public grpc_core::FilterStackTransport,
 
   std::shared_ptr<grpc_event_engine::experimental::EventEngine> event_engine;
   grpc_core::Combiner* combiner;
-  absl::BitGen bitgen;
 
   // On the client side, when the transport is first created, the
   // endpoint will already have been added to this pollset_set, and it
@@ -471,7 +492,6 @@ struct grpc_chttp2_transport final : public grpc_core::FilterStackTransport,
   grpc_event_engine::experimental::EventEngine::TaskHandle
       keepalive_ping_timer_handle =
           grpc_event_engine::experimental::EventEngine::TaskHandle::kInvalid;
-  ;
   /// time duration in between pings
   grpc_core::Duration keepalive_time;
   /// Tracks any adjustments to the absolute timestamp of the next keepalive
@@ -488,6 +508,7 @@ struct grpc_chttp2_transport final : public grpc_core::FilterStackTransport,
   uint32_t max_header_list_size_soft_limit = 0;
   grpc_core::ContextList* context_list = nullptr;
   grpc_core::RefCountedPtr<grpc_core::channelz::SocketNode> channelz_socket;
+  std::unique_ptr<ChannelzDataSource> channelz_data_source;
   uint32_t num_messages_in_next_write = 0;
   /// The number of pending induced frames (SETTINGS_ACK, PINGS_ACK and
   /// RST_STREAM) in the outgoing buffer (t->qbuf). If this number goes beyond
@@ -560,6 +581,9 @@ struct grpc_chttp2_transport final : public grpc_core::FilterStackTransport,
   grpc_core::Timestamp last_window_update_time =
       grpc_core::Timestamp::InfPast();
 
+  grpc_core::Http2StatsCollector http2_stats;
+  grpc_core::Http2ZTraceCollector http2_ztrace_collector;
+
   GPR_NO_UNIQUE_ADDRESS grpc_core::latent_see::Flow write_flow;
 };
 
@@ -670,6 +694,8 @@ struct grpc_chttp2_stream {
   int64_t write_counter = 0;
 
   grpc_core::Chttp2CallTracerWrapper call_tracer_wrapper;
+  // null by default, set by the transport data source upon first query
+  grpc_core::RefCountedPtr<grpc_core::channelz::CallNode> channelz_call_node;
 
   // TODO(yashykt): Remove call_tracer field after transition to call v3. (See
   // https://github.com/grpc/grpc/pull/38729 for more information.)
@@ -707,8 +733,6 @@ struct grpc_chttp2_stream {
       grpc_core::Timestamp::InfPast();
 };
 
-#define GRPC_ARG_PING_TIMEOUT_MS "grpc.http2.ping_timeout_ms"
-
 // EXPERIMENTAL: provide protection against overloading a server with too many
 // requests: wait for streams to be deallocated before they stop counting
 // against MAX_CONCURRENT_STREAMS

src/core/ext/transport/chttp2/transport/internal_channel_arg_names.h

@@ -0,0 +1,24 @@
+//
+//
+// Copyright 2025 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+
+#ifndef GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_INTERNAL_CHANNEL_ARG_NAMES_H
+#define GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_INTERNAL_CHANNEL_ARG_NAMES_H
+
+#define GRPC_ARG_PING_TIMEOUT_MS "grpc.http2.ping_timeout_ms"
+
+#endif  // GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_INTERNAL_CHANNEL_ARG_NAMES_H

src/core/ext/transport/chttp2/transport/parsing.cc

@@ -55,6 +55,7 @@
 #include "src/core/ext/transport/chttp2/transport/hpack_parser_table.h"
 #include "src/core/ext/transport/chttp2/transport/http2_settings.h"
 #include "src/core/ext/transport/chttp2/transport/http2_status.h"
+#include "src/core/ext/transport/chttp2/transport/http2_ztrace_collector.h"
 #include "src/core/ext/transport/chttp2/transport/internal.h"
 #include "src/core/ext/transport/chttp2/transport/legacy_frame.h"
 #include "src/core/ext/transport/chttp2/transport/ping_rate_policy.h"
@@ -73,6 +74,7 @@
 #include "src/core/telemetry/stats_data.h"
 #include "src/core/util/random_early_detection.h"
 #include "src/core/util/ref_counted_ptr.h"
+#include "src/core/util/shared_bit_gen.h"
 #include "src/core/util/status_helper.h"
 
 using grpc_core::HPackParser;
@@ -520,6 +522,12 @@ static grpc_error_handle init_header_skip_frame_parser(
 
 static grpc_error_handle init_non_header_skip_frame_parser(
     grpc_chttp2_transport* t) {
+  t->http2_ztrace_collector.Append(grpc_core::H2UnknownFrameTrace{
+      t->incoming_frame_type,
+      t->incoming_frame_flags,
+      t->incoming_stream_id,
+      t->incoming_frame_size,
+  });
   t->parser =
       grpc_chttp2_transport::Parser{"skip_parser", skip_parser, nullptr};
   return absl::OkStatus();
@@ -623,6 +631,7 @@ static grpc_error_handle init_header_frame_parser(grpc_chttp2_transport* t,
 
   t->ping_rate_policy.ReceivedDataFrame();
 
+  grpc_core::SharedBitGen g;
   // could be a new grpc_chttp2_stream or an existing grpc_chttp2_stream
   s = grpc_chttp2_parsing_lookup_stream(t, t->incoming_stream_id);
   if (s == nullptr) {
@@ -656,10 +665,10 @@ static grpc_error_handle init_header_frame_parser(grpc_chttp2_transport* t,
                             t->settings.acked().max_concurrent_streams())) {
       ++t->num_pending_induced_frames;
       grpc_slice_buffer_add(
-          &t->qbuf,
-          grpc_chttp2_rst_stream_create(
-              t->incoming_stream_id,
-              static_cast<uint32_t>(Http2ErrorCode::kRefusedStream), nullptr));
+          &t->qbuf, grpc_chttp2_rst_stream_create(
+                        t->incoming_stream_id,
+                        static_cast<uint32_t>(Http2ErrorCode::kRefusedStream),
+                        nullptr, &t->http2_ztrace_collector));
       grpc_chttp2_initiate_write(t, GRPC_CHTTP2_INITIATE_WRITE_RST_STREAM);
       return init_header_skip_frame_parser(t, priority_type, is_eoh);
     } else if (grpc_core::IsRqFastRejectEnabled() &&
@@ -672,7 +681,7 @@ static grpc_error_handle init_header_frame_parser(grpc_chttp2_transport* t,
           &t->qbuf, grpc_chttp2_rst_stream_create(
                         t->incoming_stream_id,
                         static_cast<uint32_t>(Http2ErrorCode::kEnhanceYourCalm),
-                        nullptr));
+                        nullptr, &t->http2_ztrace_collector));
       grpc_chttp2_initiate_write(t, GRPC_CHTTP2_INITIATE_WRITE_RST_STREAM);
       return init_header_skip_frame_parser(t, priority_type, is_eoh);
     } else if (GPR_UNLIKELY(
@@ -683,10 +692,10 @@ static grpc_error_handle init_header_frame_parser(grpc_chttp2_transport* t,
       // by refusing this stream.
       ++t->num_pending_induced_frames;
       grpc_slice_buffer_add(
-          &t->qbuf,
-          grpc_chttp2_rst_stream_create(
-              t->incoming_stream_id,
-              static_cast<uint32_t>(Http2ErrorCode::kRefusedStream), nullptr));
+          &t->qbuf, grpc_chttp2_rst_stream_create(
+                        t->incoming_stream_id,
+                        static_cast<uint32_t>(Http2ErrorCode::kRefusedStream),
+                        nullptr, &t->http2_ztrace_collector));
       grpc_chttp2_initiate_write(t, GRPC_CHTTP2_INITIATE_WRITE_RST_STREAM);
       return init_header_skip_frame_parser(t, priority_type, is_eoh);
     } else if (GPR_UNLIKELY(t->stream_map.size() >=
@@ -694,16 +703,16 @@ static grpc_error_handle init_header_frame_parser(grpc_chttp2_transport* t,
                             grpc_core::RandomEarlyDetection(
                                 t->settings.local().max_concurrent_streams(),
                                 t->settings.acked().max_concurrent_streams())
-                                .Reject(t->stream_map.size(), t->bitgen))) {
+                                .Reject(t->stream_map.size(), g))) {
       // We are under the limit of max concurrent streams for the current
       // setting, but are over the next value that will be advertised.
       // Apply some backpressure by randomly not accepting new streams.
       ++t->num_pending_induced_frames;
       grpc_slice_buffer_add(
-          &t->qbuf,
-          grpc_chttp2_rst_stream_create(
-              t->incoming_stream_id,
-              static_cast<uint32_t>(Http2ErrorCode::kRefusedStream), nullptr));
+          &t->qbuf, grpc_chttp2_rst_stream_create(
+                        t->incoming_stream_id,
+                        static_cast<uint32_t>(Http2ErrorCode::kRefusedStream),
+                        nullptr, &t->http2_ztrace_collector));
       grpc_chttp2_initiate_write(t, GRPC_CHTTP2_INITIATE_WRITE_RST_STREAM);
       return init_header_skip_frame_parser(t, priority_type, is_eoh);
     } else if (t->sent_goaway_state == GRPC_CHTTP2_FINAL_GOAWAY_SENT ||
@@ -730,7 +739,7 @@ static grpc_error_handle init_header_frame_parser(grpc_chttp2_transport* t,
           &t->qbuf, grpc_chttp2_rst_stream_create(
                         t->incoming_stream_id,
                         static_cast<uint32_t>(Http2ErrorCode::kEnhanceYourCalm),
-                        nullptr));
+                        nullptr, &t->http2_ztrace_collector));
       grpc_chttp2_initiate_write(t, GRPC_CHTTP2_INITIATE_WRITE_RST_STREAM);
       t->last_new_stream_id = t->incoming_stream_id;
       return init_header_skip_frame_parser(t, priority_type, is_eoh);
@@ -972,17 +981,23 @@ grpc_error_handle grpc_chttp2_header_parser_parse(void* hpack_parser,
   if (s != nullptr) {
     s->call_tracer_wrapper.RecordIncomingBytes(
         {0, 0, GRPC_SLICE_LENGTH(slice)});
-    call_tracer =
-        grpc_core::IsCallTracerTransportFixEnabled()
-            ? s->call_tracer
-            : s->arena->GetContext<grpc_core::CallTracerAnnotationInterface>();
+    call_tracer = s->call_tracer;
   }
-  grpc_error_handle error = parser->Parse(
-      slice, is_last != 0, absl::BitGenRef(t->bitgen), call_tracer);
+  grpc_core::SharedBitGen g;
+  grpc_error_handle error =
+      parser->Parse(slice, is_last != 0, absl::BitGenRef(g), call_tracer);
   if (!error.ok()) {
     return error;
   }
   if (is_last) {
+    t->http2_ztrace_collector.Append([t]() {
+      return grpc_core::H2HeaderTrace<true>{
+          t->incoming_stream_id,
+          (t->incoming_frame_flags & GRPC_CHTTP2_DATA_FLAG_END_HEADERS) != 0,
+          (t->incoming_frame_flags & GRPC_CHTTP2_DATA_FLAG_END_STREAM) != 0,
+          t->incoming_frame_type == GRPC_CHTTP2_FRAME_CONTINUATION,
+          t->incoming_frame_size};
+    });
     // need to check for null stream: this can occur if we receive an invalid
     // stream id on a header
     if (s != nullptr) {

src/core/ext/transport/chttp2/transport/ping_rate_policy.cc

@@ -25,12 +25,6 @@
 #include "src/core/lib/experiments/experiments.h"
 #include "src/core/util/match.h"
 
-// How many pings do we allow to be inflight at any given time?
-// In older versions of gRPC this was implicitly 1.
-// With the multiping experiment we allow this to rise to 100 by default.
-// TODO(ctiller): consider making this public API
-#define GRPC_ARG_HTTP2_MAX_INFLIGHT_PINGS "grpc.http2.max_inflight_pings"
-
 namespace grpc_core {
 
 namespace {
@@ -64,9 +58,16 @@ void Chttp2PingRatePolicy::SetDefaults(const ChannelArgs& args) {
 Chttp2PingRatePolicy::RequestSendPingResult
 Chttp2PingRatePolicy::RequestSendPing(Duration next_allowed_ping_interval,
                                       size_t inflight_pings) const {
-  if (max_inflight_pings_ > 0 &&
-      inflight_pings > static_cast<size_t>(max_inflight_pings_)) {
-    return TooManyRecentPings{};
+  if (max_inflight_pings_ > 0) {
+    if (!IsMaxInflightPingsStrictLimitEnabled()) {
+      if (inflight_pings > static_cast<size_t>(max_inflight_pings_)) {
+        return TooManyRecentPings{};
+      }
+    } else {
+      if (inflight_pings >= static_cast<size_t>(max_inflight_pings_)) {
+        return TooManyRecentPings{};
+      }
+    }
   }
   const Timestamp next_allowed_ping =
       last_ping_sent_time_ + next_allowed_ping_interval;

src/core/ext/transport/chttp2/transport/ping_rate_policy.h

@@ -27,6 +27,12 @@
 
 namespace grpc_core {
 
+// How many pings do we allow to be inflight at any given time?
+// In older versions of gRPC this was implicitly 1.
+// With the multiping experiment we allow this to rise to 100 by default.
+// TODO(ctiller): consider making this public API
+#define GRPC_ARG_HTTP2_MAX_INFLIGHT_PINGS "grpc.http2.max_inflight_pings"
+
 class Chttp2PingRatePolicy {
  public:
   explicit Chttp2PingRatePolicy(const ChannelArgs& args, bool is_client);

src/core/ext/transport/chttp2/transport/writing.cc

@@ -38,7 +38,6 @@
 #include "src/core/channelz/channelz.h"
 #include "src/core/ext/transport/chttp2/transport/call_tracer_wrapper.h"
 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
-#include "src/core/ext/transport/chttp2/transport/context_list_entry.h"
 #include "src/core/ext/transport/chttp2/transport/flow_control.h"
 #include "src/core/ext/transport/chttp2/transport/frame_data.h"
 #include "src/core/ext/transport/chttp2/transport/frame_ping.h"
@@ -48,6 +47,7 @@
 #include "src/core/ext/transport/chttp2/transport/hpack_encoder.h"
 #include "src/core/ext/transport/chttp2/transport/http2_settings.h"
 #include "src/core/ext/transport/chttp2/transport/http2_status.h"
+#include "src/core/ext/transport/chttp2/transport/http2_ztrace_collector.h"
 #include "src/core/ext/transport/chttp2/transport/internal.h"
 #include "src/core/ext/transport/chttp2/transport/legacy_frame.h"
 #include "src/core/ext/transport/chttp2/transport/ping_callbacks.h"
@@ -64,11 +64,13 @@
 #include "src/core/lib/transport/bdp_estimator.h"
 #include "src/core/lib/transport/transport.h"
 #include "src/core/telemetry/call_tracer.h"
+#include "src/core/telemetry/context_list_entry.h"
 #include "src/core/telemetry/stats.h"
 #include "src/core/telemetry/stats_data.h"
 #include "src/core/util/match.h"
 #include "src/core/util/ref_counted.h"
 #include "src/core/util/ref_counted_ptr.h"
+#include "src/core/util/shared_bit_gen.h"
 #include "src/core/util/time.h"
 #include "src/core/util/useful.h"
 
@@ -125,7 +127,10 @@ static void maybe_initiate_ping(grpc_chttp2_transport* t) {
                                           t->ping_callbacks.pings_inflight()),
       [t](grpc_core::Chttp2PingRatePolicy::SendGranted) {
         t->ping_rate_policy.SentPing();
-        const uint64_t id = t->ping_callbacks.StartPing(t->bitgen);
+        grpc_core::SharedBitGen g;
+        const uint64_t id = t->ping_callbacks.StartPing(g);
+        t->http2_ztrace_collector.Append(
+            grpc_core::H2PingTrace<false>{false, id});
         grpc_slice_buffer_add(t->outbuf.c_slice_buffer(),
                               grpc_chttp2_ping_create(false, id));
         t->keepalive_incoming_data_wanted = true;
@@ -253,13 +258,16 @@ namespace {
 class WriteContext {
  public:
   explicit WriteContext(grpc_chttp2_transport* t) : t_(t) {
-    grpc_core::global_stats().IncrementHttp2WritesBegun();
-    grpc_core::global_stats().IncrementHttp2WriteTargetSize(target_write_size_);
+    t->http2_stats.IncrementHttp2WritesBegun();
+    t->http2_stats.IncrementHttp2WriteTargetSize(target_write_size_);
   }
 
   void FlushSettings() {
     auto update = t_->settings.MaybeSendUpdate();
     if (update.has_value()) {
+      t_->http2_ztrace_collector.Append([&update]() {
+        return grpc_core::H2SettingsTrace<false>{false, update->settings};
+      });
       grpc_core::Http2Frame frame(std::move(*update));
       Serialize(absl::Span<grpc_core::Http2Frame>(&frame, 1), t_->outbuf);
       if (t_->keepalive_timeout != grpc_core::Duration::Infinity()) {
@@ -290,6 +298,8 @@ class WriteContext {
     uint32_t transport_announce = t_->flow_control.MaybeSendUpdate(
         t_->outbuf.c_slice_buffer()->count > 0);
     if (transport_announce) {
+      t_->http2_ztrace_collector.Append(
+          grpc_core::H2WindowUpdateTrace<false>{0, transport_announce});
       grpc_slice_buffer_add(
           t_->outbuf.c_slice_buffer(),
           grpc_chttp2_window_update_create(0, transport_announce, nullptr));
@@ -303,6 +313,8 @@ class WriteContext {
     // delayed by crypto operations.
     target_write_size_ = 0;
     for (size_t i = 0; i < t_->ping_ack_count; i++) {
+      t_->http2_ztrace_collector.Append(
+          grpc_core::H2PingTrace<false>{true, t_->ping_acks[i]});
       grpc_slice_buffer_add(t_->outbuf.c_slice_buffer(),
                             grpc_chttp2_ping_create(true, t_->ping_acks[i]));
     }
@@ -386,11 +398,14 @@ class DataSendContext {
   }
 
   uint32_t max_outgoing() const {
-    return grpc_core::Clamp<uint32_t>(
+    return grpc_core::Clamp<int64_t>(
         std::min<int64_t>(
             {t_->settings.peer().max_frame_size(), stream_remote_window(),
              t_->flow_control.remote_window(),
-             static_cast<int64_t>(write_context_->target_write_size())}),
+             static_cast<int64_t>(write_context_->target_write_size()) -
+                 (grpc_core::IsChttp2BoundWriteSizeEnabled()
+                      ? static_cast<int64_t>(t_->outbuf.Length())
+                      : static_cast<int64_t>(0))}),
         0, std::numeric_limits<uint32_t>::max());
   }
 
@@ -405,6 +420,7 @@ class DataSendContext {
                      s_->send_trailing_metadata->empty();
     grpc_chttp2_encode_data(s_->id, &s_->flow_controlled_buffer, send_bytes,
                             is_last_frame_, &s_->call_tracer_wrapper,
+                            &t_->http2_ztrace_collector,
                             t_->outbuf.c_slice_buffer());
     sfc_upd_.SentData(send_bytes);
     s_->sending_bytes += send_bytes;
@@ -463,7 +479,7 @@ class StreamWriteContext {
               t_->settings.peer()
                   .allow_true_binary_metadata(),     // use_true_binary_metadata
               t_->settings.peer().max_frame_size(),  // max_frame_size
-              &s_->call_tracer_wrapper},
+              &s_->call_tracer_wrapper, &t_->http2_ztrace_collector},
           *s_->send_initial_metadata, t_->outbuf.c_slice_buffer());
       grpc_chttp2_reset_ping_clock(t_);
       write_context_->IncInitialMetadataWrites();
@@ -475,30 +491,16 @@ class StreamWriteContext {
     grpc_chttp2_complete_closure_step(t_, &s_->send_initial_metadata_finished,
                                       absl::OkStatus(),
                                       "send_initial_metadata_finished");
-    if (!grpc_core::IsCallTracerTransportFixEnabled()) {
-      if (s_->parent_call_tracer != nullptr) {
-        grpc_core::HttpAnnotation::WriteStats write_stats;
-        write_stats.target_write_size = write_context_->target_write_size();
-        s_->parent_call_tracer->RecordAnnotation(
-            grpc_core::HttpAnnotation(
-                grpc_core::HttpAnnotation::Type::kHeadWritten,
-                gpr_now(GPR_CLOCK_REALTIME))
-                .Add(s_->t->flow_control.stats())
-                .Add(s_->flow_control.stats())
-                .Add(write_stats));
-      }
-    } else {
-      if (s_->call_tracer != nullptr && s_->call_tracer->IsSampled()) {
-        grpc_core::HttpAnnotation::WriteStats write_stats;
-        write_stats.target_write_size = write_context_->target_write_size();
-        s_->call_tracer->RecordAnnotation(
-            grpc_core::HttpAnnotation(
-                grpc_core::HttpAnnotation::Type::kHeadWritten,
-                gpr_now(GPR_CLOCK_REALTIME))
-                .Add(s_->t->flow_control.stats())
-                .Add(s_->flow_control.stats())
-                .Add(write_stats));
-      }
+    if (s_->call_tracer != nullptr && s_->call_tracer->IsSampled()) {
+      grpc_core::HttpAnnotation::WriteStats write_stats;
+      write_stats.target_write_size = write_context_->target_write_size();
+      s_->call_tracer->RecordAnnotation(
+          grpc_core::HttpAnnotation(
+              grpc_core::HttpAnnotation::Type::kHeadWritten,
+              gpr_now(GPR_CLOCK_REALTIME))
+              .Add(s_->t->flow_control.stats())
+              .Add(s_->flow_control.stats())
+              .Add(write_stats));
     }
   }
 
@@ -509,6 +511,8 @@ class StreamWriteContext {
     const uint32_t stream_announce = s_->flow_control.MaybeSendUpdate();
     if (stream_announce == 0) return;
 
+    t_->http2_ztrace_collector.Append(
+        grpc_core::H2WindowUpdateTrace<false>{s_->id, stream_announce});
     grpc_slice_buffer_add(
         t_->outbuf.c_slice_buffer(),
         grpc_chttp2_window_update_create(s_->id, stream_announce,
@@ -528,13 +532,23 @@ class StreamWriteContext {
 
     if (!data_send_context.AnyOutgoing()) {
       if (t_->flow_control.remote_window() <= 0) {
+        t_->http2_ztrace_collector.Append(grpc_core::H2FlowControlStall{
+            t_->flow_control.remote_window(),
+            data_send_context.stream_remote_window(), s_->id});
         grpc_core::global_stats().IncrementHttp2TransportStalls();
         report_stall(t_, s_, "transport");
         grpc_chttp2_list_add_stalled_by_transport(t_, s_);
       } else if (data_send_context.stream_remote_window() <= 0) {
+        t_->http2_ztrace_collector.Append(grpc_core::H2FlowControlStall{
+            t_->flow_control.remote_window(),
+            data_send_context.stream_remote_window(), s_->id});
         grpc_core::global_stats().IncrementHttp2StreamStalls();
         report_stall(t_, s_, "stream");
         grpc_chttp2_list_add_stalled_by_stream(t_, s_);
+      } else if (grpc_core::IsChttp2BoundWriteSizeEnabled()) {
+        GRPC_CHTTP2_STREAM_REF(s_, "chttp2_writing:fork");
+        grpc_chttp2_list_add_writable_stream(t_, s_);
+        stream_became_writable_ = true;
       }
       return;  // early out: nothing to do
     }
@@ -566,12 +580,14 @@ class StreamWriteContext {
     if (s_->send_trailing_metadata->empty()) {
       grpc_chttp2_encode_data(s_->id, &s_->flow_controlled_buffer, 0, true,
                               &s_->call_tracer_wrapper,
+                              &t_->http2_ztrace_collector,
                               t_->outbuf.c_slice_buffer());
     } else {
       t_->hpack_compressor.EncodeHeaders(
           grpc_core::HPackCompressor::EncodeHeaderOptions{
               s_->id, true, t_->settings.peer().allow_true_binary_metadata(),
-              t_->settings.peer().max_frame_size(), &s_->call_tracer_wrapper},
+              t_->settings.peer().max_frame_size(), &s_->call_tracer_wrapper,
+              &t_->http2_ztrace_collector},
           *s_->send_trailing_metadata, t_->outbuf.c_slice_buffer());
     }
     write_context_->IncTrailingMetadataWrites();
@@ -636,26 +652,16 @@ class StreamWriteContext {
           t_->outbuf.c_slice_buffer(),
           grpc_chttp2_rst_stream_create(
               s_->id, static_cast<uint32_t>(Http2ErrorCode::kNoError),
-              &s_->call_tracer_wrapper));
+              &s_->call_tracer_wrapper, &t_->http2_ztrace_collector));
     }
     grpc_chttp2_mark_stream_closed(t_, s_, !t_->is_client, true,
                                    absl::OkStatus());
-    if (!grpc_core::IsCallTracerTransportFixEnabled()) {
-      if (s_->parent_call_tracer != nullptr) {
-        s_->parent_call_tracer->RecordAnnotation(
-            grpc_core::HttpAnnotation(grpc_core::HttpAnnotation::Type::kEnd,
-                                      gpr_now(GPR_CLOCK_REALTIME))
-                .Add(s_->t->flow_control.stats())
-                .Add(s_->flow_control.stats()));
-      }
-    } else {
-      if (s_->call_tracer != nullptr && s_->call_tracer->IsSampled()) {
-        s_->call_tracer->RecordAnnotation(
-            grpc_core::HttpAnnotation(grpc_core::HttpAnnotation::Type::kEnd,
-                                      gpr_now(GPR_CLOCK_REALTIME))
-                .Add(s_->t->flow_control.stats())
-                .Add(s_->flow_control.stats()));
-      }
+    if (s_->call_tracer != nullptr && s_->call_tracer->IsSampled()) {
+      s_->call_tracer->RecordAnnotation(
+          grpc_core::HttpAnnotation(grpc_core::HttpAnnotation::Type::kEnd,
+                                    gpr_now(GPR_CLOCK_REALTIME))
+              .Add(s_->t->flow_control.stats())
+              .Add(s_->flow_control.stats()));
     }
   }
 
@@ -672,6 +678,10 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
 
   int64_t outbuf_relative_start_pos = 0;
   WriteContext ctx(t);
+
+  t->http2_ztrace_collector.Append(grpc_core::H2BeginWriteCycle{
+      static_cast<uint32_t>(ctx.target_write_size())});
+
   ctx.FlushSettings();
   ctx.FlushPingAcks();
   ctx.FlushQueuedBuffers();
@@ -734,6 +744,7 @@ void grpc_chttp2_end_write(grpc_chttp2_transport* t, grpc_error_handle error) {
   grpc_chttp2_stream* s;
 
   t->write_flow.End();
+  t->http2_ztrace_collector.Append(grpc_core::H2EndWriteCycle{});
 
   if (t->channelz_socket != nullptr) {
     t->channelz_socket->RecordMessagesSent(t->num_messages_in_next_write);

src/core/ext/transport/inproc/inproc_transport.cc

@@ -73,6 +73,9 @@ class InprocServerTransport final : public ServerTransport {
   ClientTransport* client_transport() override { return nullptr; }
   ServerTransport* server_transport() override { return this; }
   absl::string_view GetTransportName() const override { return "inproc"; }
+  RefCountedPtr<channelz::SocketNode> GetSocketNode() const override {
+    return nullptr;
+  }
   void SetPollset(grpc_stream*, grpc_pollset*) override {}
   void SetPollsetSet(grpc_stream*, grpc_pollset_set*) override {}
   void PerformOp(grpc_transport_op* op) override {
@@ -212,6 +215,9 @@ class InprocClientTransport final : public ClientTransport {
   ClientTransport* client_transport() override { return this; }
   ServerTransport* server_transport() override { return nullptr; }
   absl::string_view GetTransportName() const override { return "inproc"; }
+  RefCountedPtr<channelz::SocketNode> GetSocketNode() const override {
+    return nullptr;
+  }
   void SetPollset(grpc_stream*, grpc_pollset*) override {}
   void SetPollsetSet(grpc_stream*, grpc_pollset_set*) override {}
   void PerformOp(grpc_transport_op*) override { Crash("unimplemented"); }
@@ -258,8 +264,7 @@ RefCountedPtr<Channel> MakeInprocChannel(Server* server,
       server->SetupTransport(server_transport.get(), nullptr,
                              server->channel_args()
                                  .Remove(GRPC_ARG_MAX_CONNECTION_IDLE_MS)
-                                 .Remove(GRPC_ARG_MAX_CONNECTION_AGE_MS),
-                             nullptr);
+                                 .Remove(GRPC_ARG_MAX_CONNECTION_AGE_MS));
   if (!error.ok()) {
     return MakeLameChannel("Failed to create server channel", std::move(error));
   }

src/core/ext/transport/inproc/legacy_inproc_transport.cc

@@ -124,6 +124,10 @@ struct inproc_transport final : public grpc_core::FilterStackTransport {
   void SetPollsetSet(grpc_stream* stream,
                      grpc_pollset_set* pollset_set) override;
   void PerformOp(grpc_transport_op* op) override;
+  grpc_core::RefCountedPtr<grpc_core::channelz::SocketNode> GetSocketNode()
+      const override {
+    return nullptr;
+  }
 
   size_t SizeOfStream() const override;
   bool HackyDisableStreamOpBatchCoalescingInConnectedChannel() const override {
@@ -1264,8 +1268,8 @@ grpc_channel* grpc_legacy_inproc_channel_create(grpc_server* server,
   inproc_transports_create(&server_transport, &client_transport);
 
   // TODO(ncteisen): design and support channelz GetSocket for inproc.
-  grpc_error_handle error = core_server->SetupTransport(
-      server_transport, nullptr, server_args, nullptr);
+  grpc_error_handle error =
+      core_server->SetupTransport(server_transport, nullptr, server_args);
   grpc_channel* channel = nullptr;
   if (error.ok()) {
     auto new_channel = grpc_core::ChannelCreate(

src/core/ext/upb-gen/envoy/admin/v3/certs.upb.h

@@ -698,6 +698,10 @@ UPB_INLINE envoy_admin_v3_SubjectAlternateName_name_oneofcases envoy_admin_v3_Su
   return (envoy_admin_v3_SubjectAlternateName_name_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_admin_v3_SubjectAlternateName_clear_name(envoy_admin_v3_SubjectAlternateName* msg) {
+  const upb_MiniTableField field = {1, UPB_SIZE(12, 16), -9, kUpb_NoSub, 9, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__admin__v3__SubjectAlternateName_msg_init, &field);
+}
 UPB_INLINE void envoy_admin_v3_SubjectAlternateName_clear_dns(envoy_admin_v3_SubjectAlternateName* msg) {
   const upb_MiniTableField field = {1, UPB_SIZE(12, 16), -9, kUpb_NoSub, 9, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);

src/core/ext/upb-gen/envoy/config/accesslog/v3/accesslog.upb.h

@@ -127,6 +127,10 @@ UPB_INLINE envoy_config_accesslog_v3_AccessLog_config_type_oneofcases envoy_conf
   return (envoy_config_accesslog_v3_AccessLog_config_type_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_accesslog_v3_AccessLog_clear_config_type(envoy_config_accesslog_v3_AccessLog* msg) {
+  const upb_MiniTableField field = {4, UPB_SIZE(20, 40), UPB_SIZE(-17, -13), 1, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__accesslog__v3__AccessLog_msg_init, &field);
+}
 UPB_INLINE void envoy_config_accesslog_v3_AccessLog_clear_name(envoy_config_accesslog_v3_AccessLog* msg) {
   const upb_MiniTableField field = {1, UPB_SIZE(24, 16), 0, kUpb_NoSub, 9, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);
@@ -262,6 +266,10 @@ UPB_INLINE envoy_config_accesslog_v3_AccessLogFilter_filter_specifier_oneofcases
   return (envoy_config_accesslog_v3_AccessLogFilter_filter_specifier_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_accesslog_v3_AccessLogFilter_clear_filter_specifier(envoy_config_accesslog_v3_AccessLogFilter* msg) {
+  const upb_MiniTableField field = {1, UPB_SIZE(12, 16), -9, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__accesslog__v3__AccessLogFilter_msg_init, &field);
+}
 UPB_INLINE void envoy_config_accesslog_v3_AccessLogFilter_clear_status_code_filter(envoy_config_accesslog_v3_AccessLogFilter* msg) {
   const upb_MiniTableField field = {1, UPB_SIZE(12, 16), -9, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);
@@ -1797,6 +1805,10 @@ UPB_INLINE envoy_config_accesslog_v3_ExtensionFilter_config_type_oneofcases envo
   return (envoy_config_accesslog_v3_ExtensionFilter_config_type_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_accesslog_v3_ExtensionFilter_clear_config_type(envoy_config_accesslog_v3_ExtensionFilter* msg) {
+  const upb_MiniTableField field = {3, UPB_SIZE(12, 32), -9, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__accesslog__v3__ExtensionFilter_msg_init, &field);
+}
 UPB_INLINE void envoy_config_accesslog_v3_ExtensionFilter_clear_name(envoy_config_accesslog_v3_ExtensionFilter* msg) {
   const upb_MiniTableField field = {1, 16, 0, kUpb_NoSub, 9, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);

src/core/ext/upb-gen/envoy/config/bootstrap/v3/bootstrap.upb.h

@@ -52,7 +52,6 @@ typedef struct envoy_config_bootstrap_v3_Bootstrap_ApplicationLogConfig { upb_Me
 typedef struct envoy_config_bootstrap_v3_Bootstrap_ApplicationLogConfig_LogFormat { upb_Message UPB_PRIVATE(base); } envoy_config_bootstrap_v3_Bootstrap_ApplicationLogConfig_LogFormat;
 typedef struct envoy_config_bootstrap_v3_Bootstrap_DeferredStatOptions { upb_Message UPB_PRIVATE(base); } envoy_config_bootstrap_v3_Bootstrap_DeferredStatOptions;
 typedef struct envoy_config_bootstrap_v3_Bootstrap_GrpcAsyncClientManagerConfig { upb_Message UPB_PRIVATE(base); } envoy_config_bootstrap_v3_Bootstrap_GrpcAsyncClientManagerConfig;
-typedef struct envoy_config_bootstrap_v3_Bootstrap_CertificateProviderInstancesEntry { upb_Message UPB_PRIVATE(base); } envoy_config_bootstrap_v3_Bootstrap_CertificateProviderInstancesEntry;
 typedef struct envoy_config_bootstrap_v3_Admin { upb_Message UPB_PRIVATE(base); } envoy_config_bootstrap_v3_Admin;
 typedef struct envoy_config_bootstrap_v3_ClusterManager { upb_Message UPB_PRIVATE(base); } envoy_config_bootstrap_v3_ClusterManager;
 typedef struct envoy_config_bootstrap_v3_ClusterManager_OutlierDetection { upb_Message UPB_PRIVATE(base); } envoy_config_bootstrap_v3_ClusterManager_OutlierDetection;
@@ -152,6 +151,10 @@ UPB_INLINE envoy_config_bootstrap_v3_Bootstrap_stats_flush_oneofcases envoy_conf
   return (envoy_config_bootstrap_v3_Bootstrap_stats_flush_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_bootstrap_v3_Bootstrap_clear_stats_flush(envoy_config_bootstrap_v3_Bootstrap* msg) {
+  const upb_MiniTableField field = {29, 14, UPB_SIZE(-145, -17), kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__bootstrap__v3__Bootstrap_msg_init, &field);
+}
 UPB_INLINE void envoy_config_bootstrap_v3_Bootstrap_clear_node(envoy_config_bootstrap_v3_Bootstrap* msg) {
   const upb_MiniTableField field = {1, UPB_SIZE(16, 88), 64, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);
@@ -1992,6 +1995,10 @@ UPB_INLINE envoy_config_bootstrap_v3_Bootstrap_ApplicationLogConfig_LogFormat_lo
   return (envoy_config_bootstrap_v3_Bootstrap_ApplicationLogConfig_LogFormat_log_format_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_bootstrap_v3_Bootstrap_ApplicationLogConfig_LogFormat_clear_log_format(envoy_config_bootstrap_v3_Bootstrap_ApplicationLogConfig_LogFormat* msg) {
+  const upb_MiniTableField field = {1, UPB_SIZE(12, 16), -9, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__bootstrap__v3__Bootstrap__ApplicationLogConfig__LogFormat_msg_init, &field);
+}
 UPB_INLINE void envoy_config_bootstrap_v3_Bootstrap_ApplicationLogConfig_LogFormat_clear_json_format(envoy_config_bootstrap_v3_Bootstrap_ApplicationLogConfig_LogFormat* msg) {
   const upb_MiniTableField field = {1, UPB_SIZE(12, 16), -9, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);
@@ -2166,27 +2173,6 @@ UPB_INLINE struct google_protobuf_Duration* envoy_config_bootstrap_v3_Bootstrap_
   return sub;
 }
 
-/* envoy.config.bootstrap.v3.Bootstrap.CertificateProviderInstancesEntry */
-
-UPB_INLINE upb_StringView envoy_config_bootstrap_v3_Bootstrap_CertificateProviderInstancesEntry_key(const envoy_config_bootstrap_v3_Bootstrap_CertificateProviderInstancesEntry* msg) {
-  upb_StringView ret;
-  _upb_msg_map_key(msg, &ret, 0);
-  return ret;
-}
-UPB_INLINE const struct envoy_config_core_v3_TypedExtensionConfig* envoy_config_bootstrap_v3_Bootstrap_CertificateProviderInstancesEntry_value(const envoy_config_bootstrap_v3_Bootstrap_CertificateProviderInstancesEntry* msg) {
-  struct envoy_config_core_v3_TypedExtensionConfig* ret;
-  _upb_msg_map_value(msg, &ret, sizeof(ret));
-  return ret;
-}
-UPB_INLINE bool envoy_config_bootstrap_v3_Bootstrap_CertificateProviderInstancesEntry_has_value(const envoy_config_bootstrap_v3_Bootstrap_CertificateProviderInstancesEntry* msg) {
-  const upb_MiniTableField field = {2, 32, 64, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
-  return upb_Message_HasBaseField(UPB_UPCAST(msg), &field);
-}
-
-UPB_INLINE void envoy_config_bootstrap_v3_Bootstrap_CertificateProviderInstancesEntry_set_value(envoy_config_bootstrap_v3_Bootstrap_CertificateProviderInstancesEntry *msg, struct envoy_config_core_v3_TypedExtensionConfig* value) {
-  _upb_msg_map_set_value(msg, &value, sizeof(struct envoy_config_core_v3_TypedExtensionConfig*));
-}
-
 /* envoy.config.bootstrap.v3.Admin */
 
 UPB_INLINE envoy_config_bootstrap_v3_Admin* envoy_config_bootstrap_v3_Admin_new(upb_Arena* arena) {
@@ -3380,6 +3366,10 @@ UPB_INLINE envoy_config_bootstrap_v3_RuntimeLayer_layer_specifier_oneofcases env
   return (envoy_config_bootstrap_v3_RuntimeLayer_layer_specifier_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_bootstrap_v3_RuntimeLayer_clear_layer_specifier(envoy_config_bootstrap_v3_RuntimeLayer* msg) {
+  const upb_MiniTableField field = {2, UPB_SIZE(12, 32), -9, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__bootstrap__v3__RuntimeLayer_msg_init, &field);
+}
 UPB_INLINE void envoy_config_bootstrap_v3_RuntimeLayer_clear_name(envoy_config_bootstrap_v3_RuntimeLayer* msg) {
   const upb_MiniTableField field = {1, 16, 0, kUpb_NoSub, 9, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);

src/core/ext/upb-gen/envoy/config/cluster/v3/cluster.upb.h

@@ -64,7 +64,6 @@ typedef struct envoy_config_cluster_v3_Cluster_CommonLbConfig_LocalityWeightedLb
 typedef struct envoy_config_cluster_v3_Cluster_CommonLbConfig_ConsistentHashingLbConfig { upb_Message UPB_PRIVATE(base); } envoy_config_cluster_v3_Cluster_CommonLbConfig_ConsistentHashingLbConfig;
 typedef struct envoy_config_cluster_v3_Cluster_RefreshRate { upb_Message UPB_PRIVATE(base); } envoy_config_cluster_v3_Cluster_RefreshRate;
 typedef struct envoy_config_cluster_v3_Cluster_PreconnectPolicy { upb_Message UPB_PRIVATE(base); } envoy_config_cluster_v3_Cluster_PreconnectPolicy;
-typedef struct envoy_config_cluster_v3_Cluster_TypedExtensionProtocolOptionsEntry { upb_Message UPB_PRIVATE(base); } envoy_config_cluster_v3_Cluster_TypedExtensionProtocolOptionsEntry;
 typedef struct envoy_config_cluster_v3_LoadBalancingPolicy { upb_Message UPB_PRIVATE(base); } envoy_config_cluster_v3_LoadBalancingPolicy;
 typedef struct envoy_config_cluster_v3_LoadBalancingPolicy_Policy { upb_Message UPB_PRIVATE(base); } envoy_config_cluster_v3_LoadBalancingPolicy_Policy;
 typedef struct envoy_config_cluster_v3_UpstreamConnectionOptions { upb_Message UPB_PRIVATE(base); } envoy_config_cluster_v3_UpstreamConnectionOptions;
@@ -277,6 +276,10 @@ UPB_INLINE envoy_config_cluster_v3_Cluster_cluster_discovery_type_oneofcases env
   return (envoy_config_cluster_v3_Cluster_cluster_discovery_type_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_cluster_v3_Cluster_clear_cluster_discovery_type(envoy_config_cluster_v3_Cluster* msg) {
+  const upb_MiniTableField field = {2, UPB_SIZE(176, 352), UPB_SIZE(-173, -33), kUpb_NoSub, 5, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__cluster__v3__Cluster_msg_init, &field);
+}
 typedef enum {
   envoy_config_cluster_v3_Cluster_lb_config_ring_hash_lb_config = 23,
   envoy_config_cluster_v3_Cluster_lb_config_maglev_lb_config = 52,
@@ -290,6 +293,10 @@ UPB_INLINE envoy_config_cluster_v3_Cluster_lb_config_oneofcases envoy_config_clu
   return (envoy_config_cluster_v3_Cluster_lb_config_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_cluster_v3_Cluster_clear_lb_config(envoy_config_cluster_v3_Cluster* msg) {
+  const upb_MiniTableField field = {23, UPB_SIZE(184, 360), UPB_SIZE(-181, -37), 14, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__cluster__v3__Cluster_msg_init, &field);
+}
 UPB_INLINE void envoy_config_cluster_v3_Cluster_clear_name(envoy_config_cluster_v3_Cluster* msg) {
   const upb_MiniTableField field = {1, UPB_SIZE(188, 40), 0, kUpb_NoSub, 9, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);
@@ -3315,6 +3322,10 @@ UPB_INLINE envoy_config_cluster_v3_Cluster_CommonLbConfig_locality_config_specif
   return (envoy_config_cluster_v3_Cluster_CommonLbConfig_locality_config_specifier_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_cluster_v3_Cluster_CommonLbConfig_clear_locality_config_specifier(envoy_config_cluster_v3_Cluster_CommonLbConfig* msg) {
+  const upb_MiniTableField field = {2, UPB_SIZE(32, 48), UPB_SIZE(-29, -13), 1, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__cluster__v3__Cluster__CommonLbConfig_msg_init, &field);
+}
 UPB_INLINE void envoy_config_cluster_v3_Cluster_CommonLbConfig_clear_healthy_panic_threshold(envoy_config_cluster_v3_Cluster_CommonLbConfig* msg) {
   const upb_MiniTableField field = {1, UPB_SIZE(12, 16), 64, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);
@@ -3961,27 +3972,6 @@ UPB_INLINE struct google_protobuf_DoubleValue* envoy_config_cluster_v3_Cluster_P
   return sub;
 }
 
-/* envoy.config.cluster.v3.Cluster.TypedExtensionProtocolOptionsEntry */
-
-UPB_INLINE upb_StringView envoy_config_cluster_v3_Cluster_TypedExtensionProtocolOptionsEntry_key(const envoy_config_cluster_v3_Cluster_TypedExtensionProtocolOptionsEntry* msg) {
-  upb_StringView ret;
-  _upb_msg_map_key(msg, &ret, 0);
-  return ret;
-}
-UPB_INLINE const struct google_protobuf_Any* envoy_config_cluster_v3_Cluster_TypedExtensionProtocolOptionsEntry_value(const envoy_config_cluster_v3_Cluster_TypedExtensionProtocolOptionsEntry* msg) {
-  struct google_protobuf_Any* ret;
-  _upb_msg_map_value(msg, &ret, sizeof(ret));
-  return ret;
-}
-UPB_INLINE bool envoy_config_cluster_v3_Cluster_TypedExtensionProtocolOptionsEntry_has_value(const envoy_config_cluster_v3_Cluster_TypedExtensionProtocolOptionsEntry* msg) {
-  const upb_MiniTableField field = {2, 32, 64, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
-  return upb_Message_HasBaseField(UPB_UPCAST(msg), &field);
-}
-
-UPB_INLINE void envoy_config_cluster_v3_Cluster_TypedExtensionProtocolOptionsEntry_set_value(envoy_config_cluster_v3_Cluster_TypedExtensionProtocolOptionsEntry *msg, struct google_protobuf_Any* value) {
-  _upb_msg_map_set_value(msg, &value, sizeof(struct google_protobuf_Any*));
-}
-
 /* envoy.config.cluster.v3.LoadBalancingPolicy */
 
 UPB_INLINE envoy_config_cluster_v3_LoadBalancingPolicy* envoy_config_cluster_v3_LoadBalancingPolicy_new(upb_Arena* arena) {

src/core/ext/upb-gen/envoy/config/common/matcher/v3/matcher.upb.h

@@ -35,7 +35,6 @@ typedef struct envoy_config_common_matcher_v3_Matcher_MatcherList_Predicate_Pred
 typedef struct envoy_config_common_matcher_v3_Matcher_MatcherList_FieldMatcher { upb_Message UPB_PRIVATE(base); } envoy_config_common_matcher_v3_Matcher_MatcherList_FieldMatcher;
 typedef struct envoy_config_common_matcher_v3_Matcher_MatcherTree { upb_Message UPB_PRIVATE(base); } envoy_config_common_matcher_v3_Matcher_MatcherTree;
 typedef struct envoy_config_common_matcher_v3_Matcher_MatcherTree_MatchMap { upb_Message UPB_PRIVATE(base); } envoy_config_common_matcher_v3_Matcher_MatcherTree_MatchMap;
-typedef struct envoy_config_common_matcher_v3_Matcher_MatcherTree_MatchMap_MapEntry { upb_Message UPB_PRIVATE(base); } envoy_config_common_matcher_v3_Matcher_MatcherTree_MatchMap_MapEntry;
 typedef struct envoy_config_common_matcher_v3_MatchPredicate { upb_Message UPB_PRIVATE(base); } envoy_config_common_matcher_v3_MatchPredicate;
 typedef struct envoy_config_common_matcher_v3_MatchPredicate_MatchSet { upb_Message UPB_PRIVATE(base); } envoy_config_common_matcher_v3_MatchPredicate_MatchSet;
 typedef struct envoy_config_common_matcher_v3_HttpHeadersMatch { upb_Message UPB_PRIVATE(base); } envoy_config_common_matcher_v3_HttpHeadersMatch;
@@ -93,6 +92,10 @@ UPB_INLINE envoy_config_common_matcher_v3_Matcher_matcher_type_oneofcases envoy_
   return (envoy_config_common_matcher_v3_Matcher_matcher_type_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_common_matcher_v3_Matcher_clear_matcher_type(envoy_config_common_matcher_v3_Matcher* msg) {
+  const upb_MiniTableField field = {1, UPB_SIZE(20, 24), UPB_SIZE(-17, -13), 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__common__matcher__v3__Matcher_msg_init, &field);
+}
 UPB_INLINE void envoy_config_common_matcher_v3_Matcher_clear_matcher_list(envoy_config_common_matcher_v3_Matcher* msg) {
   const upb_MiniTableField field = {1, UPB_SIZE(20, 24), UPB_SIZE(-17, -13), 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);
@@ -231,6 +234,10 @@ UPB_INLINE envoy_config_common_matcher_v3_Matcher_OnMatch_on_match_oneofcases en
   return (envoy_config_common_matcher_v3_Matcher_OnMatch_on_match_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_common_matcher_v3_Matcher_OnMatch_clear_on_match(envoy_config_common_matcher_v3_Matcher_OnMatch* msg) {
+  const upb_MiniTableField field = {1, UPB_SIZE(12, 16), -9, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__common__matcher__v3__Matcher__OnMatch_msg_init, &field);
+}
 UPB_INLINE void envoy_config_common_matcher_v3_Matcher_OnMatch_clear_matcher(envoy_config_common_matcher_v3_Matcher_OnMatch* msg) {
   const upb_MiniTableField field = {1, UPB_SIZE(12, 16), -9, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);
@@ -446,6 +453,10 @@ UPB_INLINE envoy_config_common_matcher_v3_Matcher_MatcherList_Predicate_match_ty
   return (envoy_config_common_matcher_v3_Matcher_MatcherList_Predicate_match_type_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_common_matcher_v3_Matcher_MatcherList_Predicate_clear_match_type(envoy_config_common_matcher_v3_Matcher_MatcherList_Predicate* msg) {
+  const upb_MiniTableField field = {1, UPB_SIZE(12, 16), -9, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__common__matcher__v3__Matcher__MatcherList__Predicate_msg_init, &field);
+}
 UPB_INLINE void envoy_config_common_matcher_v3_Matcher_MatcherList_Predicate_clear_single_predicate(envoy_config_common_matcher_v3_Matcher_MatcherList_Predicate* msg) {
   const upb_MiniTableField field = {1, UPB_SIZE(12, 16), -9, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);
@@ -614,6 +625,10 @@ UPB_INLINE envoy_config_common_matcher_v3_Matcher_MatcherList_Predicate_SinglePr
   return (envoy_config_common_matcher_v3_Matcher_MatcherList_Predicate_SinglePredicate_matcher_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_common_matcher_v3_Matcher_MatcherList_Predicate_SinglePredicate_clear_matcher(envoy_config_common_matcher_v3_Matcher_MatcherList_Predicate_SinglePredicate* msg) {
+  const upb_MiniTableField field = {2, UPB_SIZE(20, 24), UPB_SIZE(-17, -13), 1, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__common__matcher__v3__Matcher__MatcherList__Predicate__SinglePredicate_msg_init, &field);
+}
 UPB_INLINE void envoy_config_common_matcher_v3_Matcher_MatcherList_Predicate_SinglePredicate_clear_input(envoy_config_common_matcher_v3_Matcher_MatcherList_Predicate_SinglePredicate* msg) {
   const upb_MiniTableField field = {1, UPB_SIZE(12, 16), 64, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);
@@ -956,6 +971,10 @@ UPB_INLINE envoy_config_common_matcher_v3_Matcher_MatcherTree_tree_type_oneofcas
   return (envoy_config_common_matcher_v3_Matcher_MatcherTree_tree_type_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_common_matcher_v3_Matcher_MatcherTree_clear_tree_type(envoy_config_common_matcher_v3_Matcher_MatcherTree* msg) {
+  const upb_MiniTableField field = {2, UPB_SIZE(20, 24), UPB_SIZE(-17, -13), 1, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__common__matcher__v3__Matcher__MatcherTree_msg_init, &field);
+}
 UPB_INLINE void envoy_config_common_matcher_v3_Matcher_MatcherTree_clear_input(envoy_config_common_matcher_v3_Matcher_MatcherTree* msg) {
   const upb_MiniTableField field = {1, UPB_SIZE(12, 16), 64, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);
@@ -1180,27 +1199,6 @@ UPB_INLINE bool envoy_config_common_matcher_v3_Matcher_MatcherTree_MatchMap_map_
   return _upb_Map_Delete(map, &key, 0, NULL);
 }
 
-/* envoy.config.common.matcher.v3.Matcher.MatcherTree.MatchMap.MapEntry */
-
-UPB_INLINE upb_StringView envoy_config_common_matcher_v3_Matcher_MatcherTree_MatchMap_MapEntry_key(const envoy_config_common_matcher_v3_Matcher_MatcherTree_MatchMap_MapEntry* msg) {
-  upb_StringView ret;
-  _upb_msg_map_key(msg, &ret, 0);
-  return ret;
-}
-UPB_INLINE const envoy_config_common_matcher_v3_Matcher_OnMatch* envoy_config_common_matcher_v3_Matcher_MatcherTree_MatchMap_MapEntry_value(const envoy_config_common_matcher_v3_Matcher_MatcherTree_MatchMap_MapEntry* msg) {
-  envoy_config_common_matcher_v3_Matcher_OnMatch* ret;
-  _upb_msg_map_value(msg, &ret, sizeof(ret));
-  return ret;
-}
-UPB_INLINE bool envoy_config_common_matcher_v3_Matcher_MatcherTree_MatchMap_MapEntry_has_value(const envoy_config_common_matcher_v3_Matcher_MatcherTree_MatchMap_MapEntry* msg) {
-  const upb_MiniTableField field = {2, 32, 64, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
-  return upb_Message_HasBaseField(UPB_UPCAST(msg), &field);
-}
-
-UPB_INLINE void envoy_config_common_matcher_v3_Matcher_MatcherTree_MatchMap_MapEntry_set_value(envoy_config_common_matcher_v3_Matcher_MatcherTree_MatchMap_MapEntry *msg, envoy_config_common_matcher_v3_Matcher_OnMatch* value) {
-  _upb_msg_map_set_value(msg, &value, sizeof(envoy_config_common_matcher_v3_Matcher_OnMatch*));
-}
-
 /* envoy.config.common.matcher.v3.MatchPredicate */
 
 UPB_INLINE envoy_config_common_matcher_v3_MatchPredicate* envoy_config_common_matcher_v3_MatchPredicate_new(upb_Arena* arena) {
@@ -1255,6 +1253,10 @@ UPB_INLINE envoy_config_common_matcher_v3_MatchPredicate_rule_oneofcases envoy_c
   return (envoy_config_common_matcher_v3_MatchPredicate_rule_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_common_matcher_v3_MatchPredicate_clear_rule(envoy_config_common_matcher_v3_MatchPredicate* msg) {
+  const upb_MiniTableField field = {1, UPB_SIZE(12, 16), -9, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__common__matcher__v3__MatchPredicate_msg_init, &field);
+}
 UPB_INLINE void envoy_config_common_matcher_v3_MatchPredicate_clear_or_match(envoy_config_common_matcher_v3_MatchPredicate* msg) {
   const upb_MiniTableField field = {1, UPB_SIZE(12, 16), -9, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);
@@ -1924,6 +1926,10 @@ UPB_INLINE envoy_config_common_matcher_v3_HttpGenericBodyMatch_GenericTextMatch_
   return (envoy_config_common_matcher_v3_HttpGenericBodyMatch_GenericTextMatch_rule_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_common_matcher_v3_HttpGenericBodyMatch_GenericTextMatch_clear_rule(envoy_config_common_matcher_v3_HttpGenericBodyMatch_GenericTextMatch* msg) {
+  const upb_MiniTableField field = {1, UPB_SIZE(12, 16), -9, kUpb_NoSub, 9, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__common__matcher__v3__HttpGenericBodyMatch__GenericTextMatch_msg_init, &field);
+}
 UPB_INLINE void envoy_config_common_matcher_v3_HttpGenericBodyMatch_GenericTextMatch_clear_string_match(envoy_config_common_matcher_v3_HttpGenericBodyMatch_GenericTextMatch* msg) {
   const upb_MiniTableField field = {1, UPB_SIZE(12, 16), -9, kUpb_NoSub, 9, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);

src/core/ext/upb-gen/envoy/config/core/v3/address.upb.h

@@ -164,6 +164,10 @@ UPB_INLINE envoy_config_core_v3_EnvoyInternalAddress_address_name_specifier_oneo
   return (envoy_config_core_v3_EnvoyInternalAddress_address_name_specifier_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_core_v3_EnvoyInternalAddress_clear_address_name_specifier(envoy_config_core_v3_EnvoyInternalAddress* msg) {
+  const upb_MiniTableField field = {1, UPB_SIZE(20, 32), -9, kUpb_NoSub, 9, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__core__v3__EnvoyInternalAddress_msg_init, &field);
+}
 UPB_INLINE void envoy_config_core_v3_EnvoyInternalAddress_clear_server_listener_name(envoy_config_core_v3_EnvoyInternalAddress* msg) {
   const upb_MiniTableField field = {1, UPB_SIZE(20, 32), -9, kUpb_NoSub, 9, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);
@@ -248,6 +252,10 @@ UPB_INLINE envoy_config_core_v3_SocketAddress_port_specifier_oneofcases envoy_co
   return (envoy_config_core_v3_SocketAddress_port_specifier_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_core_v3_SocketAddress_clear_port_specifier(envoy_config_core_v3_SocketAddress* msg) {
+  const upb_MiniTableField field = {3, UPB_SIZE(36, 56), -17, kUpb_NoSub, 13, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__core__v3__SocketAddress_msg_init, &field);
+}
 UPB_INLINE void envoy_config_core_v3_SocketAddress_clear_protocol(envoy_config_core_v3_SocketAddress* msg) {
   const upb_MiniTableField field = {1, 12, 0, kUpb_NoSub, 5, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);
@@ -956,6 +964,10 @@ UPB_INLINE envoy_config_core_v3_Address_address_oneofcases envoy_config_core_v3_
   return (envoy_config_core_v3_Address_address_oneofcases)upb_Message_WhichOneofFieldNumber(
       UPB_UPCAST(msg), &field);
 }
+UPB_INLINE void envoy_config_core_v3_Address_clear_address(envoy_config_core_v3_Address* msg) {
+  const upb_MiniTableField field = {1, UPB_SIZE(12, 16), -9, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
+  upb_Message_ClearOneof(UPB_UPCAST(msg), &envoy__config__core__v3__Address_msg_init, &field);
+}
 UPB_INLINE void envoy_config_core_v3_Address_clear_socket_address(envoy_config_core_v3_Address* msg) {
   const upb_MiniTableField field = {1, UPB_SIZE(12, 16), -9, 0, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)};
   upb_Message_ClearBaseField(UPB_UPCAST(msg), &field);