stats/opentelemetry: Add usage of metrics registry (grpc#7410)

experimental/stats/metricregistry.go

@@ -23,8 +23,13 @@ import (
 	"testing"
 
 	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal"
 )
 
+func init() {
+	internal.SnapshotMetricRegistryForTesting = snapshotMetricsRegistryForTesting
+}
+
 var logger = grpclog.Component("metrics-registry")
 
 // DefaultMetrics are the default metrics registered through global metrics
@@ -54,6 +59,10 @@ type MetricDescriptor struct {
 	// The type of metric. This is set by the metric registry, and not intended
 	// to be set by a component registering a metric.
 	Type MetricType
+	// Bounds are the bounds of this metric. This only applies to histogram
+	// metrics. If unset or set with length 0, stats handlers will fall back to
+	// default bounds.
+	Bounds []float64
 }
 
 // MetricType is the type of metric.

internal/internal.go

@@ -215,6 +215,12 @@ var (
 
 	// SetConnectedAddress sets the connected address for a SubConnState.
 	SetConnectedAddress any // func(scs *SubConnState, addr resolver.Address)
+
+	// SnapshotMetricRegistryForTesting snapshots the global data of the metric
+	// registry. Registers a cleanup function on the provided testing.T that
+	// sets the metric registry to its original state. Only called in testing
+	// functions.
+	SnapshotMetricRegistryForTesting any // func(t *testing.T)
 )
 
 // HealthChecker defines the signature of the client-side LB channel health

stats/opentelemetry/client_metrics.go

@@ -33,8 +33,8 @@ import (
 )
 
 type clientStatsHandler struct {
-	options Options
-
+	estats.MetricsRecorder
+	options       Options
 	clientMetrics clientMetrics
 }
 
@@ -52,14 +52,20 @@ func (h *clientStatsHandler) initializeMetrics() {
 
 	metrics := h.options.MetricsOptions.Metrics
 	if metrics == nil {
-		metrics = DefaultMetrics
+		metrics = DefaultMetrics()
 	}
 
 	h.clientMetrics.attemptStarted = createInt64Counter(metrics.Metrics(), "grpc.client.attempt.started", meter, otelmetric.WithUnit("attempt"), otelmetric.WithDescription("Number of client call attempts started."))
 	h.clientMetrics.attemptDuration = createFloat64Histogram(metrics.Metrics(), "grpc.client.attempt.duration", meter, otelmetric.WithUnit("s"), otelmetric.WithDescription("End-to-end time taken to complete a client call attempt."), otelmetric.WithExplicitBucketBoundaries(DefaultLatencyBounds...))
 	h.clientMetrics.attemptSentTotalCompressedMessageSize = createInt64Histogram(metrics.Metrics(), "grpc.client.attempt.sent_total_compressed_message_size", meter, otelmetric.WithUnit("By"), otelmetric.WithDescription("Compressed message bytes sent per client call attempt."), otelmetric.WithExplicitBucketBoundaries(DefaultSizeBounds...))
 	h.clientMetrics.attemptRcvdTotalCompressedMessageSize = createInt64Histogram(metrics.Metrics(), "grpc.client.attempt.rcvd_total_compressed_message_size", meter, otelmetric.WithUnit("By"), otelmetric.WithDescription("Compressed message bytes received per call attempt."), otelmetric.WithExplicitBucketBoundaries(DefaultSizeBounds...))
 	h.clientMetrics.callDuration = createFloat64Histogram(metrics.Metrics(), "grpc.client.call.duration", meter, otelmetric.WithUnit("s"), otelmetric.WithDescription("Time taken by gRPC to complete an RPC from application's perspective."), otelmetric.WithExplicitBucketBoundaries(DefaultLatencyBounds...))
+
+	rm := &registryMetrics{
+		optionalLabels: h.options.MetricsOptions.OptionalLabels,
+	}
+	h.MetricsRecorder = rm
+	rm.registerMetrics(metrics, meter)
 }
 
 func (h *clientStatsHandler) unaryInterceptor(ctx context.Context, method string, req, reply any, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {

stats/opentelemetry/csm/observability_test.go

@@ -206,13 +206,13 @@ func (s) TestCSMPluginOptionUnary(t *testing.T) {
 				serverOptionWithCSMPluginOption(opentelemetry.Options{
 					MetricsOptions: opentelemetry.MetricsOptions{
 						MeterProvider: provider,
-						Metrics:       opentelemetry.DefaultMetrics,
+						Metrics:       opentelemetry.DefaultMetrics(),
 					}}, po),
 			}
 			dopts := []grpc.DialOption{dialOptionWithCSMPluginOption(opentelemetry.Options{
 				MetricsOptions: opentelemetry.MetricsOptions{
 					MeterProvider:  provider,
-					Metrics:        opentelemetry.DefaultMetrics,
+					Metrics:        opentelemetry.DefaultMetrics(),
 					OptionalLabels: []string{"csm.service_name", "csm.service_namespace_name"},
 				},
 			}, po)}
@@ -368,13 +368,13 @@ func (s) TestCSMPluginOptionStreaming(t *testing.T) {
 				serverOptionWithCSMPluginOption(opentelemetry.Options{
 					MetricsOptions: opentelemetry.MetricsOptions{
 						MeterProvider: provider,
-						Metrics:       opentelemetry.DefaultMetrics,
+						Metrics:       opentelemetry.DefaultMetrics(),
 					}}, po),
 			}
 			dopts := []grpc.DialOption{dialOptionWithCSMPluginOption(opentelemetry.Options{
 				MetricsOptions: opentelemetry.MetricsOptions{
 					MeterProvider:  provider,
-					Metrics:        opentelemetry.DefaultMetrics,
+					Metrics:        opentelemetry.DefaultMetrics(),
 					OptionalLabels: []string{"csm.service_name", "csm.service_namespace_name"},
 				},
 			}, po)}
@@ -460,7 +460,7 @@ func (s) TestXDSLabels(t *testing.T) {
 	dopts := []grpc.DialOption{dialOptionWithCSMPluginOption(opentelemetry.Options{
 		MetricsOptions: opentelemetry.MetricsOptions{
 			MeterProvider:  provider,
-			Metrics:        opentelemetry.DefaultMetrics,
+			Metrics:        opentelemetry.DefaultMetrics(),
 			OptionalLabels: []string{"csm.service_name", "csm.service_namespace_name"},
 		},
 	}, po), grpc.WithUnaryInterceptor(unaryInterceptorAttachXDSLabels)}

stats/opentelemetry/e2e_test.go

@@ -52,9 +52,7 @@ func Test(t *testing.T) {
 // component and the server.
 func setup(t *testing.T, methodAttributeFilter func(string) bool) (*metric.ManualReader, *stubserver.StubServer) {
 	reader := metric.NewManualReader()
-	provider := metric.NewMeterProvider(
-		metric.WithReader(reader),
-	)
+	provider := metric.NewMeterProvider(metric.WithReader(reader))
 	ss := &stubserver.StubServer{
 		UnaryCallF: func(ctx context.Context, in *testpb.SimpleRequest) (*testpb.SimpleResponse, error) {
 			return &testpb.SimpleResponse{Payload: &testpb.Payload{
@@ -74,12 +72,12 @@ func setup(t *testing.T, methodAttributeFilter func(string) bool) (*metric.Manua
 	if err := ss.Start([]grpc.ServerOption{opentelemetry.ServerOption(opentelemetry.Options{
 		MetricsOptions: opentelemetry.MetricsOptions{
 			MeterProvider:         provider,
-			Metrics:               opentelemetry.DefaultMetrics,
+			Metrics:               opentelemetry.DefaultMetrics(),
 			MethodAttributeFilter: methodAttributeFilter,
 		}})}, opentelemetry.DialOption(opentelemetry.Options{
 		MetricsOptions: opentelemetry.MetricsOptions{
 			MeterProvider: provider,
-			Metrics:       opentelemetry.DefaultMetrics,
+			Metrics:       opentelemetry.DefaultMetrics(),
 		},
 	})); err != nil {
 		t.Fatalf("Error starting endpoint server: %v", err)

stats/opentelemetry/example_test.go

@@ -19,7 +19,7 @@ package opentelemetry_test
 import (
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials/insecure"
-	stats2 "google.golang.org/grpc/experimental/stats"
+	estats "google.golang.org/grpc/experimental/stats"
 	"google.golang.org/grpc/stats/opentelemetry"
 
 	"go.opentelemetry.io/otel/sdk/metric"
@@ -53,7 +53,7 @@ func Example_dialOption() {
 	opts := opentelemetry.Options{
 		MetricsOptions: opentelemetry.MetricsOptions{
 			MeterProvider: provider,
-			Metrics:       opentelemetry.DefaultMetrics, // equivalent to unset - distinct from empty
+			Metrics:       opentelemetry.DefaultMetrics(), // equivalent to unset - distinct from empty
 		},
 	}
 	do := opentelemetry.DialOption(opts)
@@ -88,7 +88,7 @@ func ExampleMetrics_excludeSome() {
 	// To exclude specific metrics, initialize Options as follows:
 	opts := opentelemetry.Options{
 		MetricsOptions: opentelemetry.MetricsOptions{
-			Metrics: opentelemetry.DefaultMetrics.Remove(opentelemetry.ClientAttemptDuration, opentelemetry.ClientAttemptRcvdCompressedTotalMessageSize),
+			Metrics: opentelemetry.DefaultMetrics().Remove(opentelemetry.ClientAttemptDuration, opentelemetry.ClientAttemptRcvdCompressedTotalMessageSize),
 		},
 	}
 	do := opentelemetry.DialOption(opts)
@@ -103,7 +103,7 @@ func ExampleMetrics_disableAll() {
 	// To disable all metrics, initialize Options as follows:
 	opts := opentelemetry.Options{
 		MetricsOptions: opentelemetry.MetricsOptions{
-			Metrics: stats2.NewMetrics(), // Distinct to nil, which creates default metrics. This empty set creates no metrics.
+			Metrics: estats.NewMetrics(), // Distinct to nil, which creates default metrics. This empty set creates no metrics.
 		},
 	}
 	do := opentelemetry.DialOption(opts)
@@ -118,7 +118,7 @@ func ExampleMetrics_enableSome() {
 	// To only create specific metrics, initialize Options as follows:
 	opts := opentelemetry.Options{
 		MetricsOptions: opentelemetry.MetricsOptions{
-			Metrics: stats2.NewMetrics(opentelemetry.ClientAttemptDuration, opentelemetry.ClientAttemptRcvdCompressedTotalMessageSize), // only create these metrics
+			Metrics: estats.NewMetrics(opentelemetry.ClientAttemptDuration, opentelemetry.ClientAttemptRcvdCompressedTotalMessageSize), // only create these metrics
 		},
 	}
 	do := opentelemetry.DialOption(opts)