[.NET7.0] Http client activity source migration (#3415)

src/OpenTelemetry.Instrumentation.Http/HttpClientInstrumentation.cs

@@ -25,13 +25,30 @@ internal class HttpClientInstrumentation : IDisposable
     {
         private readonly DiagnosticSourceSubscriber diagnosticSourceSubscriber;
 
+        private readonly Func<string, object, object, bool> isEnabled = (activityName, obj1, obj2)
+            => !activityName.Equals("System.Net.Http.HttpRequestOut");
+
         /// <summary>
         /// Initializes a new instance of the <see cref="HttpClientInstrumentation"/> class.
         /// </summary>
         /// <param name="options">Configuration options for HTTP client instrumentation.</param>
         public HttpClientInstrumentation(HttpClientInstrumentationOptions options)
         {
-            this.diagnosticSourceSubscriber = new DiagnosticSourceSubscriber(new HttpHandlerDiagnosticListener(options), null);
+            // For .NET7.0 activity will be created using activitySource.
+            // https://github.com/dotnet/runtime/blob/main/src/libraries/System.Net.Http/src/System/Net/Http/DiagnosticsHandler.cs
+            // However, in case when activity creation returns null (due to sampling)
+            // the framework will fall back to creating activity anyways due to active diagnostic source listener
+            // To prevent this, isEnabled is implemented which will return false always
+            // so that the sampler's decision is respected.
+            if (HttpHandlerDiagnosticListener.IsNet7OrGreater)
+            {
+                this.diagnosticSourceSubscriber = new DiagnosticSourceSubscriber(new HttpHandlerDiagnosticListener(options), this.isEnabled);
+            }
+            else
+            {
+                this.diagnosticSourceSubscriber = new DiagnosticSourceSubscriber(new HttpHandlerDiagnosticListener(options), null);
+            }
+
             this.diagnosticSourceSubscriber.Subscribe();
         }
 

src/OpenTelemetry.Instrumentation.Http/Implementation/HttpHandlerDiagnosticListener.cs

@@ -28,6 +28,10 @@ namespace OpenTelemetry.Instrumentation.Http.Implementation
     internal sealed class HttpHandlerDiagnosticListener : ListenerHandler
     {
         internal static readonly AssemblyName AssemblyName = typeof(HttpHandlerDiagnosticListener).Assembly.GetName();
+        internal static readonly bool IsNet7OrGreater;
+
+        // https://github.com/dotnet/runtime/blob/7d034ddbbbe1f2f40c264b323b3ed3d6b3d45e9a/src/libraries/System.Net.Http/src/System/Net/Http/DiagnosticsHandler.cs#L19
+        internal static readonly string HttpClientActivitySourceName = "System.Net.Http";
         internal static readonly string ActivitySourceName = AssemblyName.Name;
         internal static readonly Version Version = AssemblyName.Version;
         internal static readonly ActivitySource ActivitySource = new(ActivitySourceName, Version.ToString());
@@ -40,6 +44,18 @@ internal sealed class HttpHandlerDiagnosticListener : ListenerHandler
         private readonly PropertyFetcher<TaskStatus> stopRequestStatusFetcher = new("RequestTaskStatus");
         private readonly HttpClientInstrumentationOptions options;
 
+        static HttpHandlerDiagnosticListener()
+        {
+            try
+            {
+                IsNet7OrGreater = typeof(HttpClient).Assembly.GetName().Version.Major >= 7;
+            }
+            catch (Exception)
+            {
+                IsNet7OrGreater = false;
+            }
+        }
+
         public HttpHandlerDiagnosticListener(HttpClientInstrumentationOptions options)
             : base("HttpHandlerDiagnosticListener")
         {
@@ -58,7 +74,11 @@ public override void OnStartActivity(Activity activity, object payload)
             // By this time, samplers have already run and
             // activity.IsAllDataRequested populated accordingly.
 
-            if (Sdk.SuppressInstrumentation)
+            // For .NET7.0 or higher versions, activity is created using activity source
+            // However, the framework will fallback to creating activity if the sampler's decision is to drop and there is a active diagnostic listener.
+            // To prevent processing such activities we first check the source name to confirm if it was created using
+            // activity source or not.
+            if (Sdk.SuppressInstrumentation || (IsNet7OrGreater && string.IsNullOrEmpty(activity.Source.Name)))
             {
                 return;
             }
@@ -108,8 +128,11 @@ public override void OnStartActivity(Activity activity, object payload)
 
                 activity.DisplayName = HttpTagHelper.GetOperationNameForHttpMethod(request.Method);
 
-                ActivityInstrumentationHelper.SetActivitySourceProperty(activity, ActivitySource);
-                ActivityInstrumentationHelper.SetKindProperty(activity, ActivityKind.Client);
+                if (!IsNet7OrGreater)
+                {
+                    ActivityInstrumentationHelper.SetActivitySourceProperty(activity, ActivitySource);
+                    ActivityInstrumentationHelper.SetKindProperty(activity, ActivityKind.Client);
+                }
 
                 activity.SetTag(SemanticConventions.AttributeHttpMethod, HttpTagHelper.GetNameForHttpMethod(request.Method));
                 activity.SetTag(SemanticConventions.AttributeHttpHost, HttpTagHelper.GetHostTagValueFromRequestUri(request.RequestUri));
@@ -129,6 +152,15 @@ public override void OnStartActivity(Activity activity, object payload)
 
         public override void OnStopActivity(Activity activity, object payload)
         {
+            // For .NET7.0 or higher versions, activity is created using activity source
+            // However, the framework will fallback to creating activity if the sampler's decision is to drop and there is a active diagnostic listener.
+            // To prevent processing such activities we first check the source name to confirm if it was created using
+            // activity source or not.
+            if (IsNet7OrGreater && string.IsNullOrEmpty(activity.Source.Name))
+            {
+                return;
+            }
+
             if (activity.IsAllDataRequested)
             {
                 // https://github.com/dotnet/runtime/blob/master/src/libraries/System.Net.Http/src/System/Net/Http/DiagnosticsHandler.cs
@@ -178,6 +210,15 @@ public override void OnStopActivity(Activity activity, object payload)
 
         public override void OnException(Activity activity, object payload)
         {
+            // For .NET7.0 or higher versions, activity is created using activity source
+            // However, the framework will fallback to creating activity if the sampler's decision is to drop and there is a active diagnostic listener.
+            // To prevent processing such activities we first check the source name to confirm if it was created using
+            // activity source or not.
+            if (IsNet7OrGreater && string.IsNullOrEmpty(activity.Source.Name))
+            {
+                return;
+            }
+
             if (activity.IsAllDataRequested)
             {
                 if (!this.stopExceptionFetcher.TryFetch(payload, out Exception exc) || exc == null)

src/OpenTelemetry.Instrumentation.Http/TracerProviderBuilderExtensions.cs

@@ -78,8 +78,16 @@ internal static TracerProviderBuilder AddHttpClientInstrumentation(
             this TracerProviderBuilder builder,
             HttpClientInstrumentation instrumentation)
         {
-            builder.AddSource(HttpHandlerDiagnosticListener.ActivitySourceName);
-            builder.AddLegacySource("System.Net.Http.HttpRequestOut");
+            if (HttpHandlerDiagnosticListener.IsNet7OrGreater)
+            {
+                builder.AddSource(HttpHandlerDiagnosticListener.HttpClientActivitySourceName);
+            }
+            else
+            {
+                builder.AddSource(HttpHandlerDiagnosticListener.ActivitySourceName);
+                builder.AddLegacySource("System.Net.Http.HttpRequestOut");
+            }
+
             return builder.AddInstrumentation(() => instrumentation);
         }