Optimize gRPC client instrumentation for SuppressInstrumentation

open-telemetry · Mar 12, 2021 · 69ec569 · 69ec569
1 parent c404e19
commit 69ec569
Showing 1 changed file with 22 additions and 6 deletions.
diff --git a/...penTelemetry.Instrumentation.GrpcNetClient/Implementation/GrpcClientDiagnosticListener.cs b/...penTelemetry.Instrumentation.GrpcNetClient/Implementation/GrpcClientDiagnosticListener.cs
@@ -43,6 +43,22 @@ public GrpcClientDiagnosticListener(GrpcClientInstrumentationOptions options)
 
         public override void OnStartActivity(Activity activity, object payload)
         {
+            // The overall flow of what GrpcClient library does is as below:
+            // Activity.Start()
+            // DiagnosticSource.WriteEvent("Start", payload)
+            // DiagnosticSource.WriteEvent("Stop", payload)
+            // Activity.Stop()
+
+            // This method is in the WriteEvent("Start", payload) path.
+            // By this time, samplers have already run and
+            // activity.IsAllDataRequested populated accordingly.
+
+            if (Sdk.SuppressInstrumentation)
+            {
+                return;
+            }
+
+            // Ensure context propagation irrespective of sampling decision
             if (!this.startRequestFetcher.TryFetch(payload, out HttpRequestMessage request) || request == null)
             {
                 GrpcInstrumentationEventSource.Log.NullPayload(nameof(GrpcClientDiagnosticListener), nameof(this.OnStartActivity));
@@ -78,15 +94,15 @@ public override void OnStartActivity(Activity activity, object payload)
                     HttpRequestMessageContextPropagation.HeaderValueSetter);
             }
 
-            var grpcMethod = GrpcTagHelper.GetGrpcMethodFromActivity(activity);
+            if (activity.IsAllDataRequested)
+            {
+                ActivityInstrumentationHelper.SetActivitySourceProperty(activity, ActivitySource);
+                ActivityInstrumentationHelper.SetKindProperty(activity, ActivityKind.Client);
 
-            activity.DisplayName = grpcMethod?.Trim('/');
+                var grpcMethod = GrpcTagHelper.GetGrpcMethodFromActivity(activity);
 
-            ActivityInstrumentationHelper.SetActivitySourceProperty(activity, ActivitySource);
-            ActivityInstrumentationHelper.SetKindProperty(activity, ActivityKind.Client);
+                activity.DisplayName = grpcMethod?.Trim('/');
 
-            if (activity.IsAllDataRequested)
-            {
                 activity.SetTag(SemanticConventions.AttributeRpcSystem, GrpcTagHelper.RpcSystemGrpc);
 
                 if (GrpcTagHelper.TryParseRpcServiceAndRpcMethod(grpcMethod, out var rpcService, out var rpcMethod))