otelgrpc: Deprecate interceptors in favor of stats handlers (#4534)

* otelgrpc: Deprecate interceptors in favor of stats handlers

* Update opencensus example

CHANGELOG.md

@@ -28,6 +28,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 ### Deprecated
 
 - In `go.opentelemetry.io/contrib/exporters/autoexport`, `Option` was renamed to `SpanOption`. The old name is deprecated but continues to be supported as an alias. (#4229)
+- The interceptors (`UnaryClientInterceptor`, `StreamClientInterceptor`, `UnaryServerInterceptor`, `StreamServerInterceptor`, `WithInterceptorFilter`) are deprecated. Use stats handlers (`NewClientHandler`, `NewServerHandler`) instead. (#4534)
 
 ### Fixed
 

instrumentation/google.golang.org/grpc/otelgrpc/config.go

@@ -145,6 +145,8 @@ func (o tracerProviderOption) apply(c *config) {
 }
 
 // WithInterceptorFilter returns an Option to use the request filter.
+//
+// Deprecated: Use stats handlers instead.
 func WithInterceptorFilter(f Filter) Option {
 	return interceptorFilterOption{f: f}
 }

instrumentation/google.golang.org/grpc/otelgrpc/doc.go

@@ -13,33 +13,10 @@
 // limitations under the License.
 
 /*
-Package otelgrpc is the instrumentation library for [google.golang.org/grpc]
+Package otelgrpc is the instrumentation library for [google.golang.org/grpc].
 
-For now you can instrument your program which use [google.golang.org/grpc] in two ways:
+Use [NewClientHandler] with [grpc.WithStatsHandler] to instrument a gRPC client.
 
-  - by [grpc.UnaryClientInterceptor], [grpc.UnaryServerInterceptor], [grpc.StreamClientInterceptor], [grpc.StreamServerInterceptor]
-  - by [stats.Handler]
-
-Notice: Do not use both interceptors and [stats.Handler] at the same time! If so, you will get duplicated spans and the parent/child relationships between spans will also be broken.
-
-We strongly still recommand you to use [stats.Handler], mainly for two reasons:
-
-Functional advantages: [stats.Handler] has more information for user to build more flexible and granular metric, for example
-
-  - multiple different types of represent "data length": In [stats.InPayload], there exists "Length", "CompressedLength", "WireLength" to denote the size of uncompressed, compressed payload data, with or without framing data. But in interceptors, we can only got uncompressed data, and this feature is also removed due to performance problem.
-
-  - more accurate timestamp: [stats.InPayload]'s "RecvTime" and [stats.OutPayload]'s "SentTime" records more accurate timestamp that server got and sent the message, the timestamp recorded by interceptors depends on the location of this interceptors in the total interceptor chain.
-
-  - some other use cases: for example, catch failure of decoding message.
-
-Performance advantages: If too many interceptors are registered in a service, the interceptor chain can become too long, which increases the latency and processing time of the entire RPC call.
-
-[stats.Handler]: https://pkg.go.dev/google.golang.org/grpc/stats#Handler
-[grpc.UnaryClientInterceptor]: https://pkg.go.dev/google.golang.org/grpc#UnaryClientInterceptor
-[grpc.UnaryServerInterceptor]: https://pkg.go.dev/google.golang.org/grpc#UnaryServerInterceptor
-[grpc.StreamClientInterceptor]: https://pkg.go.dev/google.golang.org/grpc#StreamClientInterceptor
-[grpc.StreamServerInterceptor]: https://pkg.go.dev/google.golang.org/grpc#StreamServerInterceptor
-[stats.OutPayload]: https://pkg.go.dev/google.golang.org/grpc/stats#OutPayload
-[stats.InPayload]: https://pkg.go.dev/google.golang.org/grpc/stats#InPayload
+Use [NewServerHandler] with [grpc.StatsHandler] to instrument a gRPC server.
 */
 package otelgrpc // import "go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"

instrumentation/google.golang.org/grpc/otelgrpc/example_interceptor_test.go → instrumentation/google.golang.org/grpc/otelgrpc/example_test.go

@@ -20,18 +20,10 @@ import (
 	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
 )
 
-func ExampleStreamClientInterceptor() {
-	_, _ = grpc.Dial("localhost", grpc.WithStreamInterceptor(otelgrpc.StreamClientInterceptor()))
+func ExampleNewClientHandler() {
+	_, _ = grpc.Dial("localhost", grpc.WithStatsHandler(otelgrpc.NewClientHandler()))
 }
 
-func ExampleUnaryClientInterceptor() {
-	_, _ = grpc.Dial("localhost", grpc.WithUnaryInterceptor(otelgrpc.UnaryClientInterceptor()))
-}
-
-func ExampleStreamServerInterceptor() {
-	_ = grpc.NewServer(grpc.StreamInterceptor(otelgrpc.StreamServerInterceptor()))
-}
-
-func ExampleUnaryServerInterceptor() {
-	_ = grpc.NewServer(grpc.UnaryInterceptor(otelgrpc.UnaryServerInterceptor()))
+func ExampleNewServerHandler() {
+	_ = grpc.NewServer(grpc.StatsHandler(otelgrpc.NewServerHandler()))
 }

instrumentation/google.golang.org/grpc/otelgrpc/interceptor.go

@@ -60,6 +60,8 @@ var (
 
 // UnaryClientInterceptor returns a grpc.UnaryClientInterceptor suitable
 // for use in a grpc.Dial call.
+//
+// Deprecated: Use [NewClientHandler] instead.
 func UnaryClientInterceptor(opts ...Option) grpc.UnaryClientInterceptor {
 	cfg := newConfig(opts, "client")
 	tracer := cfg.TracerProvider.Tracer(
@@ -254,6 +256,8 @@ func (w *clientStream) sendStreamEvent(eventType streamEventType, err error) {
 
 // StreamClientInterceptor returns a grpc.StreamClientInterceptor suitable
 // for use in a grpc.Dial call.
+//
+// Deprecated: Use [NewClientHandler] instead.
 func StreamClientInterceptor(opts ...Option) grpc.StreamClientInterceptor {
 	cfg := newConfig(opts, "client")
 	tracer := cfg.TracerProvider.Tracer(
@@ -324,6 +328,8 @@ func StreamClientInterceptor(opts ...Option) grpc.StreamClientInterceptor {
 
 // UnaryServerInterceptor returns a grpc.UnaryServerInterceptor suitable
 // for use in a grpc.NewServer call.
+//
+// Deprecated: Use [NewServerHandler] instead.
 func UnaryServerInterceptor(opts ...Option) grpc.UnaryServerInterceptor {
 	cfg := newConfig(opts, "server")
 	tracer := cfg.TracerProvider.Tracer(
@@ -445,6 +451,8 @@ func wrapServerStream(ctx context.Context, ss grpc.ServerStream, cfg *config) *s
 
 // StreamServerInterceptor returns a grpc.StreamServerInterceptor suitable
 // for use in a grpc.NewServer call.
+//
+// Deprecated: Use [NewServerHandler] instead.
 func StreamServerInterceptor(opts ...Option) grpc.StreamServerInterceptor {
 	cfg := newConfig(opts, "server")
 	tracer := cfg.TracerProvider.Tracer(

instrumentation/google.golang.org/grpc/otelgrpc/test/grpc_test.go

@@ -109,21 +109,25 @@ func TestInterceptors(t *testing.T) {
 	listener, err := net.Listen("tcp", "127.0.0.1:0")
 	require.NoError(t, err, "failed to open port")
 	err = newGrpcTest(listener, []grpc.DialOption{
+		//nolint:staticcheck // Interceptors are deprecated and will be removed in the next release.
 		grpc.WithUnaryInterceptor(otelgrpc.UnaryClientInterceptor(
 			otelgrpc.WithTracerProvider(clientUnaryTP),
 			otelgrpc.WithMessageEvents(otelgrpc.ReceivedEvents, otelgrpc.SentEvents),
 		)),
+		//nolint:staticcheck // Interceptors are deprecated and will be removed in the next release.
 		grpc.WithStreamInterceptor(otelgrpc.StreamClientInterceptor(
 			otelgrpc.WithTracerProvider(clientStreamTP),
 			otelgrpc.WithMessageEvents(otelgrpc.ReceivedEvents, otelgrpc.SentEvents),
 		)),
 	},
 		[]grpc.ServerOption{
+			//nolint:staticcheck // Interceptors are deprecated and will be removed in the next release.
 			grpc.UnaryInterceptor(otelgrpc.UnaryServerInterceptor(
 				otelgrpc.WithTracerProvider(serverUnaryTP),
 				otelgrpc.WithMeterProvider(serverUnaryMP),
 				otelgrpc.WithMessageEvents(otelgrpc.ReceivedEvents, otelgrpc.SentEvents),
 			)),
+			//nolint:staticcheck // Interceptors are deprecated and will be removed in the next release.
 			grpc.StreamInterceptor(otelgrpc.StreamServerInterceptor(
 				otelgrpc.WithTracerProvider(serverStreamTP),
 				otelgrpc.WithMessageEvents(otelgrpc.ReceivedEvents, otelgrpc.SentEvents),

instrumentation/google.golang.org/grpc/otelgrpc/test/interceptor_test.go

@@ -92,19 +92,23 @@ func TestUnaryClientInterceptor(t *testing.T) {
 
 	sr := tracetest.NewSpanRecorder()
 	tp := trace.NewTracerProvider(trace.WithSpanProcessor(sr))
+	//nolint:staticcheck // Interceptors are deprecated and will be removed in the next release.
 	unaryInterceptor := otelgrpc.UnaryClientInterceptor(
 		otelgrpc.WithTracerProvider(tp),
 		otelgrpc.WithMessageEvents(otelgrpc.ReceivedEvents, otelgrpc.SentEvents),
 		otelgrpc.WithSpanOptions(oteltrace.WithAttributes(attribute.Bool("custom", true))),
 	)
+	//nolint:staticcheck // Interceptors are deprecated and will be removed in the next release.
 	unaryInterceptorOnlySentEvents := otelgrpc.UnaryClientInterceptor(
 		otelgrpc.WithTracerProvider(tp),
 		otelgrpc.WithMessageEvents(otelgrpc.SentEvents),
 	)
+	//nolint:staticcheck // Interceptors are deprecated and will be removed in the next release.
 	unaryInterceptorOnlyReceivedEvents := otelgrpc.UnaryClientInterceptor(
 		otelgrpc.WithTracerProvider(tp),
 		otelgrpc.WithMessageEvents(otelgrpc.ReceivedEvents),
 	)
+	//nolint:staticcheck // Interceptors are deprecated and will be removed in the next release.
 	unaryInterceptorNoEvents := otelgrpc.UnaryClientInterceptor(
 		otelgrpc.WithTracerProvider(tp),
 	)
@@ -405,6 +409,7 @@ func createInterceptedStreamClient(t *testing.T, method string, opts clientStrea
 	if len(opts.Events) > 0 {
 		interceptorOpts = append(interceptorOpts, otelgrpc.WithMessageEvents(opts.Events...))
 	}
+	//nolint:staticcheck // Interceptors are deprecated and will be removed in the next release.
 	streamCI := otelgrpc.StreamClientInterceptor(interceptorOpts...)
 
 	streamClient, err := streamCI(
@@ -651,6 +656,7 @@ func TestStreamClientInterceptorCancelContext(t *testing.T) {
 	// tracer
 	sr := tracetest.NewSpanRecorder()
 	tp := trace.NewTracerProvider(trace.WithSpanProcessor(sr))
+	//nolint:staticcheck // Interceptors are deprecated and will be removed in the next release.
 	streamCI := otelgrpc.StreamClientInterceptor(
 		otelgrpc.WithTracerProvider(tp),
 		otelgrpc.WithMessageEvents(otelgrpc.ReceivedEvents, otelgrpc.SentEvents),
@@ -714,6 +720,7 @@ func TestStreamClientInterceptorWithError(t *testing.T) {
 	// tracer
 	sr := tracetest.NewSpanRecorder()
 	tp := trace.NewTracerProvider(trace.WithSpanProcessor(sr))
+	//nolint:staticcheck // Interceptors are deprecated and will be removed in the next release.
 	streamCI := otelgrpc.StreamClientInterceptor(
 		otelgrpc.WithTracerProvider(tp),
 		otelgrpc.WithMessageEvents(otelgrpc.ReceivedEvents, otelgrpc.SentEvents),
@@ -877,6 +884,7 @@ func TestUnaryServerInterceptor(t *testing.T) {
 			mr := metric.NewManualReader()
 			mp := metric.NewMeterProvider(metric.WithReader(mr))
 
+			//nolint:staticcheck // Interceptors are deprecated and will be removed in the next release.
 			usi := otelgrpc.UnaryServerInterceptor(
 				otelgrpc.WithTracerProvider(tp),
 				otelgrpc.WithMeterProvider(mp),
@@ -937,6 +945,7 @@ func TestUnaryServerInterceptorEvents(t *testing.T) {
 			if len(testCase.Events) > 0 {
 				opts = append(opts, otelgrpc.WithMessageEvents(testCase.Events...))
 			}
+			//nolint:staticcheck // Interceptors are deprecated and will be removed in the next release.
 			usi := otelgrpc.UnaryServerInterceptor(opts...)
 			grpcCode := grpc_codes.OK
 			name := grpcCode.String()
@@ -998,6 +1007,7 @@ func TestStreamServerInterceptor(t *testing.T) {
 			sr := tracetest.NewSpanRecorder()
 			tp := trace.NewTracerProvider(trace.WithSpanProcessor(sr))
 
+			//nolint:staticcheck // Interceptors are deprecated and will be removed in the next release.
 			usi := otelgrpc.StreamServerInterceptor(
 				otelgrpc.WithTracerProvider(tp),
 			)
@@ -1039,6 +1049,7 @@ func TestStreamServerInterceptorEvents(t *testing.T) {
 			if len(testCase.Events) > 0 {
 				opts = append(opts, otelgrpc.WithMessageEvents(testCase.Events...))
 			}
+			//nolint:staticcheck // Interceptors are deprecated and will be removed in the next release.
 			usi := otelgrpc.StreamServerInterceptor(opts...)
 			stream := &mockServerStream{}
 

propagators/opencensus/examples/opentelemetry_server/server.go

@@ -71,8 +71,7 @@ func main() {
 	// handler to enable tracing.
 	log.Println("Starting the GRPC server, and using the OpenCensus binary propagation format.")
 	s := grpc.NewServer(
-		grpc.UnaryInterceptor(otelgrpc.UnaryServerInterceptor(otelgrpc.WithPropagators(opencensus.Binary{}))),
-		grpc.StreamInterceptor(otelgrpc.StreamServerInterceptor(otelgrpc.WithPropagators(opencensus.Binary{}))))
+		grpc.StatsHandler(otelgrpc.NewServerHandler(otelgrpc.WithPropagators(opencensus.Binary{}))))
 	pb.RegisterGreeterServer(s, &server{})
 
 	if err := s.Serve(lis); err != nil {