cds: Import Envoy load balancing extension protos. (#9133)

xds/third_party/envoy/import.sh

@@ -129,6 +129,9 @@ envoy/extensions/filters/http/fault/v3/fault.proto
 envoy/extensions/filters/http/rbac/v3/rbac.proto
 envoy/extensions/filters/http/router/v3/router.proto
 envoy/extensions/filters/network/http_connection_manager/v3/http_connection_manager.proto
+envoy/extensions/load_balancing_policies/ring_hash/v3/ring_hash.proto
+envoy/extensions/load_balancing_policies/round_robin/v3/round_robin.proto
+envoy/extensions/load_balancing_policies/wrr_locality/v3/wrr_locality.proto
 envoy/extensions/transport_sockets/tls/v3/cert.proto
 envoy/extensions/transport_sockets/tls/v3/common.proto
 envoy/extensions/transport_sockets/tls/v3/secret.proto

xds/third_party/envoy/src/main/proto/envoy/extensions/load_balancing_policies/ring_hash/v3/ring_hash.proto

@@ -0,0 +1,74 @@
+syntax = "proto3";
+
+package envoy.extensions.load_balancing_policies.ring_hash.v3;
+
+import "google/protobuf/wrappers.proto";
+
+import "udpa/annotations/status.proto";
+import "validate/validate.proto";
+
+option java_package = "io.envoyproxy.envoy.extensions.load_balancing_policies.ring_hash.v3";
+option java_outer_classname = "RingHashProto";
+option java_multiple_files = true;
+option go_package = "github.com/envoyproxy/go-control-plane/envoy/extensions/load_balancing_policies/ring_hash/v3;ring_hashv3";
+option (udpa.annotations.file_status).package_version_status = ACTIVE;
+
+// [#protodoc-title: Ring Hash Load Balancing Policy]
+
+// This configuration allows the built-in RING_HASH LB policy to be configured via the LB policy
+// extension point. See the :ref:`load balancing architecture overview
+// <arch_overview_load_balancing_types>` for more information.
+// [#extension: envoy.clusters.lb_policy]
+// [#next-free-field: 6]
+message RingHash {
+  // The hash function used to hash hosts onto the ketama ring.
+  enum HashFunction {
+    // Currently defaults to XX_HASH.
+    DEFAULT_HASH = 0;
+
+    // Use `xxHash <https://github.com/Cyan4973/xxHash>`_.
+    XX_HASH = 1;
+
+    // Use `MurmurHash2 <https://sites.google.com/site/murmurhash/>`_, this is compatible with
+    // std:hash<string> in GNU libstdc++ 3.4.20 or above. This is typically the case when compiled
+    // on Linux and not macOS.
+    MURMUR_HASH_2 = 2;
+  }
+
+  // The hash function used to hash hosts onto the ketama ring. The value defaults to
+  // :ref:`XX_HASH<envoy_v3_api_enum_value_config.cluster.v3.Cluster.RingHashLbConfig.HashFunction.XX_HASH>`.
+  HashFunction hash_function = 1 [(validate.rules).enum = {defined_only: true}];
+
+  // Minimum hash ring size. The larger the ring is (that is, the more hashes there are for each
+  // provided host) the better the request distribution will reflect the desired weights. Defaults
+  // to 1024 entries, and limited to 8M entries. See also
+  // :ref:`maximum_ring_size<envoy_v3_api_field_config.cluster.v3.Cluster.RingHashLbConfig.maximum_ring_size>`.
+  google.protobuf.UInt64Value minimum_ring_size = 2 [(validate.rules).uint64 = {lte: 8388608}];
+
+  // Maximum hash ring size. Defaults to 8M entries, and limited to 8M entries, but can be lowered
+  // to further constrain resource use. See also
+  // :ref:`minimum_ring_size<envoy_v3_api_field_config.cluster.v3.Cluster.RingHashLbConfig.minimum_ring_size>`.
+  google.protobuf.UInt64Value maximum_ring_size = 3 [(validate.rules).uint64 = {lte: 8388608}];
+
+  // If set to `true`, the cluster will use hostname instead of the resolved
+  // address as the key to consistently hash to an upstream host. Only valid for StrictDNS clusters with hostnames which resolve to a single IP address.
+  bool use_hostname_for_hashing = 4;
+
+  // Configures percentage of average cluster load to bound per upstream host. For example, with a value of 150
+  // no upstream host will get a load more than 1.5 times the average load of all the hosts in the cluster.
+  // If not specified, the load is not bounded for any upstream host. Typical value for this parameter is between 120 and 200.
+  // Minimum is 100.
+  //
+  // This is implemented based on the method described in the paper https://arxiv.org/abs/1608.01350. For the specified
+  // `hash_balance_factor`, requests to any upstream host are capped at `hash_balance_factor/100` times the average number of requests
+  // across the cluster. When a request arrives for an upstream host that is currently serving at its max capacity, linear probing
+  // is used to identify an eligible host. Further, the linear probe is implemented using a random jump in hosts ring/table to identify
+  // the eligible host (this technique is as described in the paper https://arxiv.org/abs/1908.08762 - the random jump avoids the
+  // cascading overflow effect when choosing the next host in the ring/table).
+  //
+  // If weights are specified on the hosts, they are respected.
+  //
+  // This is an O(N) algorithm, unlike other load balancers. Using a lower `hash_balance_factor` results in more hosts
+  // being probed, so use a higher value if you require better performance.
+  google.protobuf.UInt32Value hash_balance_factor = 5 [(validate.rules).uint32 = {gte: 100}];
+}

xds/third_party/envoy/src/main/proto/envoy/extensions/load_balancing_policies/round_robin/v3/round_robin.proto

@@ -0,0 +1,26 @@
+syntax = "proto3";
+
+package envoy.extensions.load_balancing_policies.round_robin.v3;
+
+import "envoy/config/cluster/v3/cluster.proto";
+
+import "udpa/annotations/status.proto";
+import "validate/validate.proto";
+
+option java_package = "io.envoyproxy.envoy.extensions.load_balancing_policies.round_robin.v3";
+option java_outer_classname = "RoundRobinProto";
+option java_multiple_files = true;
+option go_package = "github.com/envoyproxy/go-control-plane/envoy/extensions/load_balancing_policies/round_robin/v3;round_robinv3";
+option (udpa.annotations.file_status).package_version_status = ACTIVE;
+
+// [#protodoc-title: Round Robin Load Balancing Policy]
+
+// This configuration allows the built-in ROUND_ROBIN LB policy to be configured via the LB policy
+// extension point. See the :ref:`load balancing architecture overview
+// <arch_overview_load_balancing_types>` for more information.
+// [#extension: envoy.clusters.lb_policy]
+message RoundRobin {
+  // Configuration for slow start mode.
+  // If this configuration is not set, slow start will not be not enabled.
+  config.cluster.v3.Cluster.SlowStartConfig slow_start_config = 1;
+}

xds/third_party/envoy/src/main/proto/envoy/extensions/load_balancing_policies/wrr_locality/v3/wrr_locality.proto

@@ -0,0 +1,25 @@
+syntax = "proto3";
+
+package envoy.extensions.load_balancing_policies.wrr_locality.v3;
+
+import "envoy/config/cluster/v3/cluster.proto";
+
+import "udpa/annotations/status.proto";
+import "validate/validate.proto";
+
+option java_package = "io.envoyproxy.envoy.extensions.load_balancing_policies.wrr_locality.v3";
+option java_outer_classname = "WrrLocalityProto";
+option java_multiple_files = true;
+option go_package = "github.com/envoyproxy/go-control-plane/envoy/extensions/load_balancing_policies/wrr_locality/v3;wrr_localityv3";
+option (udpa.annotations.file_status).package_version_status = ACTIVE;
+
+// [#protodoc-title: Weighted Round Robin Locality-Picking Load Balancing Policy]
+
+// Configuration for the wrr_locality LB policy. See the :ref:`load balancing architecture overview
+// <arch_overview_load_balancing_types>` for more information.
+// [#extension: envoy.clusters.lb_policy]
+message WrrLocality {
+  // The child LB policy to create for endpoint-picking within the chosen locality.
+  config.cluster.v3.LoadBalancingPolicy endpoint_picking_policy = 1
+      [(validate.rules).message = {required: true}];
+}