[ASP.NET Core] Enable diagnostic source events using explicit names (#3519)

src/OpenTelemetry.Instrumentation.AspNetCore/AspNetCoreInstrumentation.cs

@@ -14,6 +14,7 @@
 // limitations under the License.
 // </copyright>
 using System;
+using System.Collections.Generic;
 using OpenTelemetry.Instrumentation.AspNetCore.Implementation;
 
 namespace OpenTelemetry.Instrumentation.AspNetCore
@@ -23,11 +24,23 @@ namespace OpenTelemetry.Instrumentation.AspNetCore
     /// </summary>
     internal class AspNetCoreInstrumentation : IDisposable
     {
+        private static readonly HashSet<string> DiagnosticSourceEvents = new()
+        {
+            "Microsoft.AspNetCore.Hosting.HttpRequestIn.Start",
+            "Microsoft.AspNetCore.Hosting.HttpRequestIn.Stop",
+            "Microsoft.AspNetCore.Mvc.BeforeAction",
+            "Microsoft.AspNetCore.Diagnostics.UnhandledException",
+            "Microsoft.AspNetCore.Hosting.UnhandledException",
+        };
+
+        private readonly Func<string, object, object, bool> isEnabled = (eventName, obj1, obj2)
+            => DiagnosticSourceEvents.Contains(eventName);
+
         private readonly DiagnosticSourceSubscriber diagnosticSourceSubscriber;
 
         public AspNetCoreInstrumentation(HttpInListener httpInListener)
         {
-            this.diagnosticSourceSubscriber = new DiagnosticSourceSubscriber(httpInListener, null);
+            this.diagnosticSourceSubscriber = new DiagnosticSourceSubscriber(httpInListener, this.isEnabled);
             this.diagnosticSourceSubscriber.Subscribe();
         }
 

src/OpenTelemetry.Instrumentation.AspNetCore/CHANGELOG.md

@@ -2,15 +2,19 @@
 
 ## Unreleased
 
-* Fix issue where when an application has an ExceptionFilter, the exception data
-  wouldn't be collected.
-  ([#3475](https://github.com/open-telemetry/opentelemetry-dotnet/pull/3475))
+* Performance improvement (Reduced memory allocation) - Updated DiagnosticSource
+event subscription to specific set of events.
+([#3519](https://github.com/open-telemetry/opentelemetry-dotnet/pull/3519))
 
 * Added overloads which accept a name to the `TracerProviderBuilder`
   `AddAspNetCoreInstrumentation` extension to allow for more fine-grained
   options management
   ([#3661](https://github.com/open-telemetry/opentelemetry-dotnet/pull/3661))
 
+* Fix issue where when an application has an ExceptionFilter, the exception data
+  wouldn't be collected.
+  ([#3475](https://github.com/open-telemetry/opentelemetry-dotnet/pull/3475))
+
 ## 1.0.0-rc9.6
 
 Released 2022-Aug-18

test/Benchmarks/Instrumentation/AspNetCoreInstrumentationBenchmarks.cs

@@ -27,17 +27,17 @@ using OpenTelemetry.Trace;
 /*
 // * Summary *
 
-BenchmarkDotNet=v0.13.1, OS=Windows 10.0.22000
+BenchmarkDotNet=v0.13.1, OS=Windows 10.0.22621
 Intel Core i7-8850H CPU 2.60GHz (Coffee Lake), 1 CPU, 12 logical and 6 physical cores
 .NET SDK=7.0.100-preview.6.22275.1
-  [Host] : .NET 6.0.8 (6.0.822.36306), X64 RyuJIT
+  [Host] : .NET 6.0.9 (6.0.922.41905), X64 RyuJIT
 
 Job=InProcess  Toolchain=InProcessEmitToolchain
 
 |                                      Method |     Mean |   Error |  StdDev |  Gen 0 | Allocated |
 |-------------------------------------------- |---------:|--------:|--------:|-------:|----------:|
-|                 UninstrumentedAspNetCoreApp | 155.6 us | 2.63 us | 2.33 us | 0.9766 |      5 KB |
-| InstrumentedAspNetCoreAppWithDefaultOptions | 176.8 us | 3.24 us | 2.70 us | 1.2207 |      7 KB |
+|                 UninstrumentedAspNetCoreApp | 164.7 us | 1.66 us | 1.39 us | 0.9766 |      5 KB |
+| InstrumentedAspNetCoreAppWithDefaultOptions | 178.7 us | 2.65 us | 2.35 us | 0.9766 |      5 KB |
 */
 
 namespace Benchmarks.Instrumentation

test/OpenTelemetry.Instrumentation.AspNetCore.Tests/BasicTests.cs

@@ -695,7 +695,7 @@ namespace OpenTelemetry.Instrumentation.AspNetCore.Tests
             AssertException(exportedItems);
         }
 
-        [Fact(Skip = "Pending Changes https://github.com/open-telemetry/opentelemetry-dotnet/issues/3495")]
+        [Fact]
         public async Task DiagnosticSourceCustomCallbacksAreReceivedOnlyForSubscribedEvents()
         {
             int numberOfCustomCallbacks = 0;
@@ -772,7 +772,7 @@ namespace OpenTelemetry.Instrumentation.AspNetCore.Tests
             Assert.Equal(1, numberOfExceptionCallbacks);
         }
 
-        [Fact(Skip = "Pending Changes https://github.com/open-telemetry/opentelemetry-dotnet/issues/3495")]
+        [Fact]
         public async Task DiagnosticSourceExceptionCallBackIsNotReceivedForExceptionsHandledInMiddleware()
         {
             int numberOfExceptionCallbacks = 0;
@@ -823,6 +823,8 @@ namespace OpenTelemetry.Instrumentation.AspNetCore.Tests
             }
 
             Assert.Equal(0, numberOfExceptionCallbacks);
+
+            await app.DisposeAsync();
         }
 
         public void Dispose()