fix: allow configurable http2 initial window size. fixes #2429

packages/grpc-js/README.md

@@ -70,6 +70,7 @@ Many channel arguments supported in `grpc` are not supported in `@grpc/grpc-js`.
   - `grpc-node.max_session_memory`
   - `grpc-node.tls_enable_trace`
   - `grpc-node.retry_max_attempts_limit`
+  - `grpc-node.http2_initial_window_size`
   - `channelOverride`
   - `channelFactoryOverride`
 

packages/grpc-js/src/channel-options.ts

@@ -64,6 +64,7 @@ export interface ChannelOptions {
   'grpc-node.tls_enable_trace'?: number;
   'grpc.lb.ring_hash.ring_size_cap'?: number;
   'grpc-node.retry_max_attempts_limit'?: number;
+  'grpc-node.http2_initial_window_size'?: number;
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   [key: string]: any;
 }
@@ -101,6 +102,7 @@ export const recognizedOptions = {
   'grpc-node.tls_enable_trace': true,
   'grpc.lb.ring_hash.ring_size_cap': true,
   'grpc-node.retry_max_attempts_limit': true,
+  'grpc-node.http2_initial_window_size': true,
 };
 
 export function channelOptionsEqual(

packages/grpc-js/src/transport.ts

@@ -672,6 +672,11 @@ export class Http2SubchannelConnector implements SubchannelConnector {
       const session = http2.connect(`http://${targetPath}`, {
         createConnection: (authority, option) => {
           return underlyingConnection;
+        },
+        settings: {
+          initialWindowSize:
+            options['grpc-node.http2_initial_window_size'] ||
+            http2.getDefaultSettings().initialWindowSize,
         }
       });
       this.session = session;