grpc: rework the window size settings to apply on the server

go/vt/grpcclient/client.go

@@ -34,10 +34,8 @@ import (
 )
 
 var (
-	keepaliveTime         = flag.Duration("grpc_keepalive_time", 0, "After a duration of this time if the client doesn't see any activity it pings the server to see if the transport is still alive.")
-	keepaliveTimeout      = flag.Duration("grpc_keepalive_timeout", 0, "After having pinged for keepalive check, the client waits for a duration of Timeout and if no activity is seen even after that the connection is closed.")
-	initialConnWindowSize = flag.Int("grpc_initial_conn_window_size", 0, "grpc initial connection window size")
-	initialWindowSize     = flag.Int("grpc_initial_window_size", 0, "grpc initial window size")
+	keepaliveTime    = flag.Duration("grpc_keepalive_time", 0, "After a duration of this time if the client doesn't see any activity it pings the server to see if the transport is still alive.")
+	keepaliveTimeout = flag.Duration("grpc_keepalive_timeout", 0, "After having pinged for keepalive check, the client waits for a duration of Timeout and if no activity is seen even after that the connection is closed.")
 )
 
 // FailFast is a self-documenting type for the grpc.FailFast.
@@ -76,12 +74,12 @@ func Dial(target string, failFast FailFast, opts ...grpc.DialOption) (*grpc.Clie
 		newopts = append(newopts, grpc.WithKeepaliveParams(kp))
 	}
 
-	if *initialConnWindowSize != 0 {
-		newopts = append(newopts, grpc.WithInitialConnWindowSize(int32(*initialConnWindowSize)))
+	if *grpccommon.InitialConnWindowSize != 0 {
+		newopts = append(newopts, grpc.WithInitialConnWindowSize(int32(*grpccommon.InitialConnWindowSize)))
 	}
 
-	if *initialWindowSize != 0 {
-		newopts = append(newopts, grpc.WithInitialWindowSize(int32(*initialWindowSize)))
+	if *grpccommon.InitialWindowSize != 0 {
+		newopts = append(newopts, grpc.WithInitialWindowSize(int32(*grpccommon.InitialWindowSize)))
 	}
 
 	newopts = append(newopts, opts...)

go/vt/grpccommon/options.go

@@ -35,6 +35,12 @@ var (
 
 	// EnableGRPCPrometheus sets a flag to enable grpc client/server grpc monitoring.
 	EnableGRPCPrometheus = flag.Bool("grpc_prometheus", false, "Enable gRPC monitoring with Prometheus")
+
+	// InitialConnWindowSize sets the initial connection window size
+	InitialConnWindowSize = flag.Int("grpc_initial_conn_window_size", 0, "grpc initial connection window size")
+
+	// InitialWindowSize sets the initial stream window size
+	InitialWindowSize = flag.Int("grpc_initial_window_size", 0, "grpc initial window size")
 )
 
 var enableTracing sync.Once

go/vt/servenv/grpc_server.go

@@ -125,6 +125,14 @@ func createGRPCServer() {
 	opts = append(opts, grpc.MaxRecvMsgSize(*grpccommon.MaxMessageSize))
 	opts = append(opts, grpc.MaxSendMsgSize(*grpccommon.MaxMessageSize))
 
+	if *grpccommon.InitialConnWindowSize != 0 {
+		opts = append(opts, grpc.InitialConnWindowSize(int32(*grpccommon.InitialConnWindowSize)))
+	}
+
+	if *grpccommon.InitialWindowSize != 0 {
+		opts = append(opts, grpc.InitialWindowSize(int32(*grpccommon.InitialWindowSize)))
+	}
+
 	if GRPCMaxConnectionAge != nil {
 		ka := keepalive.ServerParameters{
 			MaxConnectionAge: *GRPCMaxConnectionAge,