[Instrumentation.Runtime] Prefer the built-in runtime metrics for .NET 9 targets.

src/OpenTelemetry.Instrumentation.Runtime/CHANGELOG.md

@@ -9,6 +9,9 @@
 * Updated OpenTelemetry core component version(s) to `1.10.0`.
   ([#2317](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/2317))
 
+* Prefer built-in .NET runtime metrics for .NET 9 and greater.
+  ([#2339](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/2339))
+
 ## 1.9.0
 
 Released 2024-Jun-18

src/OpenTelemetry.Instrumentation.Runtime/MeterProviderBuilderExtensions.cs

@@ -11,14 +11,19 @@ namespace OpenTelemetry.Metrics;
 /// </summary>
 public static class MeterProviderBuilderExtensions
 {
+    private const string DotNetRuntimeMeterName = "System.Runtime";
+    private static readonly bool Net9OrGreater = Environment.Version.Major >= 9;
+
     /// <summary>
     /// Enables runtime instrumentation.
     /// </summary>
     /// <param name="builder"><see cref="MeterProviderBuilder"/> being configured.</param>
     /// <returns>The instance of <see cref="MeterProviderBuilder"/> to chain the calls.</returns>
     public static MeterProviderBuilder AddRuntimeInstrumentation(
         this MeterProviderBuilder builder) =>
-        AddRuntimeInstrumentation(builder, configure: null);
+            Net9OrGreater
+                ? builder.AddMeter(DotNetRuntimeMeterName)
+                : AddRuntimeInstrumentation(builder, configure: null);
 
     /// <summary>
     /// Enables runtime instrumentation.

src/OpenTelemetry.Instrumentation.Runtime/OpenTelemetry.Instrumentation.Runtime.csproj

@@ -14,8 +14,8 @@
   </ItemGroup>
 
   <ItemGroup>
-    <Compile Include="$(RepoRoot)\src\Shared\AssemblyVersionExtensions.cs" Link="Includes\AssemblyVersionExtensions.cs" />
     <Compile Include="$(RepoRoot)\src\Shared\Guard.cs" Link="Includes\Guard.cs" />
+    <Compile Include="$(RepoRoot)\src\Shared\AssemblyVersionExtensions.cs" Link="Includes\AssemblyVersionExtensions.cs" />
   </ItemGroup>
 
 </Project>

src/OpenTelemetry.Instrumentation.Runtime/README.md

@@ -48,6 +48,12 @@ to the application.
 
 ## Metrics
 
+> [!NOTE]
+> .NET 9 introduced built-in runtime metrics. As such, when applications target
+.NET 9 or greater this package registers a `Meter` to receive the built-in metrics.
+See the [Microsoft documentation](https://learn.microsoft.com/en-us/dotnet/core/diagnostics/built-in-metrics-runtime)
+ for details of the metric and attribute names for the built-in metrics.
+
 ### GC related metrics
 
 #### process.runtime.dotnet.**gc.collections.count**

test/OpenTelemetry.Instrumentation.Runtime.Tests/RuntimeMetricsTests.cs

@@ -32,12 +32,21 @@ public void RuntimeMetricsAreCaptured()
         meterProvider.ForceFlush(MaxTimeToAllowForFlush);
         Assert.True(exportedItems.Count > 1);
 
+#if NET9_0_OR_GREATER
+        var assembliesCountMetric = exportedItems.FirstOrDefault(i => i.Name == "dotnet.assembly.count");
+        Assert.NotNull(assembliesCountMetric);
+
+        var exceptionsCountMetric = exportedItems.FirstOrDefault(i => i.Name == "dotnet.exceptions");
+        Assert.NotNull(exceptionsCountMetric);
+        Assert.True(GetValue(exceptionsCountMetric) >= 1);
+#else
         var assembliesCountMetric = exportedItems.FirstOrDefault(i => i.Name == "process.runtime.dotnet.assemblies.count");
         Assert.NotNull(assembliesCountMetric);
 
         var exceptionsCountMetric = exportedItems.FirstOrDefault(i => i.Name == "process.runtime.dotnet.exceptions.count");
         Assert.NotNull(exceptionsCountMetric);
         Assert.True(GetValue(exceptionsCountMetric) >= 1);
+#endif
     }
 
     [Fact]
@@ -53,13 +62,23 @@ public void GcMetricsTest()
 
         meterProvider.ForceFlush(MaxTimeToAllowForFlush);
 
+#if NET9_0_OR_GREATER
+        // We don't need to test all metrics here as those are tested in the runtime.
+        // This is sufficient to validate that the runtime metrics are enabled.
+        var gcCountMetric = exportedItems.FirstOrDefault(i => i.Name == "dotnet.gc.collections");
+        Assert.NotNull(gcCountMetric);
+
+        var totalObjectsSize = exportedItems.FirstOrDefault(i => i.Name == "dotnet.gc.heap.total_allocated");
+        Assert.NotNull(totalObjectsSize);
+#else
         var gcCountMetric = exportedItems.FirstOrDefault(i => i.Name == "process.runtime.dotnet.gc.collections.count");
         Assert.NotNull(gcCountMetric);
 
         var totalObjectsSize = exportedItems.FirstOrDefault(i => i.Name == "process.runtime.dotnet.gc.objects.size");
         Assert.NotNull(totalObjectsSize);
+#endif
 
-#if NET
+#if NET8_0
 
         var gcAllocationSizeMetric = exportedItems.FirstOrDefault(i => i.Name == "process.runtime.dotnet.gc.allocations.size");
         Assert.NotNull(gcAllocationSizeMetric);
@@ -90,6 +109,16 @@ public void JitRelatedMetricsTest()
 
         meterProvider.ForceFlush(MaxTimeToAllowForFlush);
 
+#if NET9_0_OR_GREATER
+        var jitCompiledSizeMetric = exportedItems.FirstOrDefault(i => i.Name == "dotnet.jit.compiled_il.size");
+        Assert.NotNull(jitCompiledSizeMetric);
+
+        var jitMethodsCompiledCountMetric = exportedItems.FirstOrDefault(i => i.Name == "dotnet.jit.compiled_methods");
+        Assert.NotNull(jitMethodsCompiledCountMetric);
+
+        var jitCompilationTimeMetric = exportedItems.FirstOrDefault(i => i.Name == "dotnet.jit.compilation.time");
+        Assert.NotNull(jitCompilationTimeMetric);
+#else
         var jitCompiledSizeMetric = exportedItems.FirstOrDefault(i => i.Name == "process.runtime.dotnet.jit.il_compiled.size");
         Assert.NotNull(jitCompiledSizeMetric);
 
@@ -98,6 +127,7 @@ public void JitRelatedMetricsTest()
 
         var jitCompilationTimeMetric = exportedItems.FirstOrDefault(i => i.Name == "process.runtime.dotnet.jit.compilation_time");
         Assert.NotNull(jitCompilationTimeMetric);
+#endif
     }
 
     [Fact]
@@ -121,6 +151,15 @@ public async Task ThreadingRelatedMetricsTest()
 
         meterProvider.ForceFlush(MaxTimeToAllowForFlush);
 
+#if NET9_0_OR_GREATER
+        // We don't need to test all metrics here as those are tested in the runtime.
+        // This is sufficient to validate that the runtime metrics are enabled.
+        var lockContentionCountMetric = exportedItems.FirstOrDefault(i => i.Name == "dotnet.monitor.lock_contentions");
+        Assert.NotNull(lockContentionCountMetric);
+
+        var threadCountMetric = exportedItems.FirstOrDefault(i => i.Name == "dotnet.thread_pool.thread.count");
+        Assert.NotNull(threadCountMetric);
+#else
         var lockContentionCountMetric = exportedItems.FirstOrDefault(i => i.Name == "process.runtime.dotnet.monitor.lock_contention.count");
         Assert.NotNull(lockContentionCountMetric);
 
@@ -163,6 +202,7 @@ static void TimerCallback(object? _)
                 timers[i].Dispose();
             }
         }
+#endif
     }
 #endif