minor changes to documentation

dialoptions.go

@@ -414,8 +414,8 @@ func WithTimeout(d time.Duration) DialOption {
 // returned by f, gRPC checks the error's Temporary() method to decide if it
 // should try to reconnect to the network address.
 //
-// Note: Go overrides the OS defaults for TCP keepalive interval to 15s.
-// To retain the OS defaults, pass in a custom dialer with KeepAlive set to a negative duration.
+// Note: Go overrides the OS defaults for TCP keepalive time and interval to 15s.
+// To retain OS defaults, use a net.Dialer with the KeepAlive field set to a negative value.
 func WithContextDialer(f func(context.Context, string) (net.Conn, error)) DialOption {
 	return newFuncDialOption(func(o *dialOptions) {
 		o.copts.Dialer = f

examples/helloworld/greeter_server/main.go

@@ -48,10 +48,8 @@ func (s *server) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloRe
 
 func main() {
 	flag.Parse()
-	// ListenConfig allows options to be passed to the listener.
-	var lc net.ListenConfig
-	// Setting KeepAlive to -1 allows the listener to retain OS default TCP keep-alive interval.
-	lc.KeepAlive = time.Duration(-1)
+	// Setting KeepAlive to -1 allows the listener to retain OS default TCP keepalive time and interval.
+	lc := net.ListenConfig{KeepAlive: time.Duration(-1)}
 	lis, err := lc.Listen(context.Background(), "tcp", fmt.Sprintf(":%d", *port))
 	if err != nil {
 		log.Fatalf("failed to listen: %v", err)

internal/transport/http2_client.go

@@ -176,6 +176,7 @@ func dial(ctx context.Context, fn func(context.Context, string) (net.Conn, error
 	if networkType == "tcp" && useProxy {
 		return proxyDial(ctx, address, grpcUA)
 	}
+	// KeepAlive is set to a negative value to prevent Go's override of the TCP keepalive time and interval; retain the OS default.
 	return (&net.Dialer{KeepAlive: time.Duration(-1)}).DialContext(ctx, networkType, address)
 }
 

server.go

@@ -814,11 +814,10 @@ func (l *listenSocket) Close() error {
 // this method returns.
 // Serve will return a non-nil error unless Stop or GracefulStop is called.
 //
-// Note: Go overrides the OS defaults for TCP keepalive interval to 15s.
-// To retain the OS defaults, you will need to create a net.ListenConfig with the
-// KeepAlive parameter set to a negative value and use the Listen method on it to create
-// the net.Listener to pass to this function.
-// See https://github.com/grpc/grpc-go/blob/master/examples/helloworld/greeter_client/main.go#L51
+// Note: Go overrides OS defaults for TCP keepalive time and interval to 15s.
+// To retain OS defaults, pass a net.Listener created by calling the Listen method
+// on a net.ListenConfig with the `KeepAlive` field set to a negative value. See
+// helloworld/greeter_server/main.go for an example.
 func (s *Server) Serve(lis net.Listener) error {
 	s.mu.Lock()
 	s.printf("serving")