Add configuration XDS_CLIENT_MAX_MSG_SIZE_IN_BYTES (#797)

* Add configuration CONFIG_GRPC_XDS_SERVER_CONNECT_RETRY_INTERVAL

Signed-off-by: Renuka Fernando <renukapiyumal@gmail.com>

* Update configuration name

Signed-off-by: Renuka Fernando <renukapiyumal@gmail.com>

---------

Signed-off-by: Renuka Fernando <renukapiyumal@gmail.com>

README.md

@@ -658,10 +658,14 @@ The xDS client in the Rate limit service configure Rate limit service with the p
 In case of connection failures, the xDS Client retries the connection to the xDS server with exponential backoff and the backoff parameters are configurable.
 
 1. `XDS_CLIENT_BACKOFF_JITTER`: set to `"true"` to add jitter to the exponential backoff.
-2. `XDS_CLIENT_BACKOFF_INITIAL_INTERVAL`: The base amount of time the xDS client waits before retyring the connection after failure. Default: "10s"
+2. `XDS_CLIENT_BACKOFF_INITIAL_INTERVAL`: The base amount of time the xDS client waits before retrying the connection after failure. Default: "10s"
 3. `XDS_CLIENT_BACKOFF_MAX_INTERVAL`: The max backoff interval is the upper limit on the amount of time the xDS client will wait between retries. After reaching the max backoff interval, the next retries will continue using the max interval. Default: "60s"
 4. `XDS_CLIENT_BACKOFF_RANDOM_FACTOR`: This is a factor by which the initial interval is multiplied to calculate the next backoff interval. Default: "0.5"
 
+The followings are the gRPC connection options.
+
+1. `XDS_CLIENT_MAX_MSG_SIZE_IN_BYTES`: The maximum message size in bytes that the xDS client can receive.
+
 For more information on xDS protocol please refer to the [envoy proxy documentation](https://www.envoyproxy.io/docs/envoy/latest/api-docs/xds_protocol).
 
 You can refer to [the sample xDS configuration management server](examples/xds-sotw-config-server/README.md).

src/provider/xds_grpc_sotw_provider.go

@@ -126,13 +126,23 @@ func (p *XdsGrpcSotwProvider) watchConfigs() {
 func (p *XdsGrpcSotwProvider) getGrpcConnection() (*grpc.ClientConn, error) {
 	backOff := grpc_retry.BackoffLinearWithJitter(p.settings.ConfigGrpcXdsServerConnectRetryInterval, 0.5)
 	logger.Infof("Dialing xDS Management Server: '%s'", p.settings.ConfigGrpcXdsServerUrl)
-	return grpc.Dial(
-		p.settings.ConfigGrpcXdsServerUrl,
+	grpcOptions := []grpc.DialOption{
 		p.getGrpcTransportCredentials(),
 		grpc.WithBlock(),
 		grpc.WithStreamInterceptor(
 			grpc_retry.StreamClientInterceptor(grpc_retry.WithBackoff(backOff)),
-		))
+		),
+	}
+	maxRecvMsgSize := p.settings.XdsClientGrpcOptionsMaxMsgSizeInBytes
+	if maxRecvMsgSize != 0 {
+		logger.Infof("Setting xDS gRPC max receive message size to %d bytes", maxRecvMsgSize)
+		grpcOptions = append(grpcOptions,
+			grpc.WithDefaultCallOptions(grpc.MaxCallRecvMsgSize(maxRecvMsgSize)))
+	}
+	return grpc.Dial(
+		p.settings.ConfigGrpcXdsServerUrl,
+		grpcOptions...,
+	)
 }
 
 func (p *XdsGrpcSotwProvider) getGrpcTransportCredentials() grpc.DialOption {

src/settings/settings.go

@@ -78,6 +78,9 @@ type Settings struct {
 	XdsClientBackoffRandomFactor    float64       `envconfig:"XDS_CLIENT_BACKOFF_RANDOM_FACTOR" default:"0.5"`
 	XdsClientBackoffJitter          bool          `envconfig:"XDS_CLIENT_BACKOFF_JITTER" default:"true"`
 
+	// xDS client gRPC options
+	XdsClientGrpcOptionsMaxMsgSizeInBytes int `envconfig:"XDS_CLIENT_MAX_MSG_SIZE_IN_BYTES" default:""`
+
 	// Stats-related settings
 	UseDogStatsd           bool              `envconfig:"USE_DOG_STATSD" default:"false"`
 	UseDogStatsdMogrifiers []string          `envconfig:"USE_DOG_STATSD_MOGRIFIERS" default:""`