[AzureMonitorDistro] Add ASP.NET Core and HTTP Client metrics instrumentation

sdk/monitor/Azure.Monitor.OpenTelemetry.AspNetCore/CHANGELOG.md

@@ -4,6 +4,28 @@
 
 ### Features Added
 
+* ASP.NET Core and HTTP Client Metrics Collection: Implemented conditional
+  instrumentation for ASP.NET Core and HTTP Client metrics to optimize telemetry
+  collection across various .NET runtime environments. This update ensures the
+  most relevant and efficient metrics collection tailored to the specific
+  version of the .NET runtime being used.
+  * For .NET 8 and above, we now utilize built-in Metrics for
+    `Microsoft.AspNetCore.Hosting` and `System.Net.Http`. This approach
+    leverages the latest .NET runtime capabilities to provide detailed insights
+    directly from the runtime environment. See detailed metrics documentation
+    for
+    [Microsoft.AspNetCore.Hosting](https://learn.microsoft.com/en-in/dotnet/core/diagnostics/built-in-metrics-aspnetcore#microsoftaspnetcorehosting)
+    and
+    [System.Net.Http](https://learn.microsoft.com/en-in/dotnet/core/diagnostics/built-in-metrics-system-net#systemnethttp).
+  * For environments below .NET 8, distro uses ASP.NET Core and HTTP Client
+  Instrumentation to ensure compatibility with older runtime versions. Detailed
+  metrics information can be found in the [ASP.NET Core
+  Instrumentation](https://github.com/open-telemetry/opentelemetry-dotnet/blob/main/src/OpenTelemetry.Instrumentation.AspNetCore/README.md)
+  and [HTTP Client
+  Instrumentation](https://github.com/open-telemetry/opentelemetry-dotnet/blob/main/src/OpenTelemetry.Instrumentation.Http/README.md)
+  documentation.
+  ([#42307](https://github.com/Azure/azure-sdk-for-net/pull/42307))
+
 ### Breaking Changes
 
 ### Bugs Fixed

sdk/monitor/Azure.Monitor.OpenTelemetry.AspNetCore/README.md

@@ -19,8 +19,11 @@ The Azure Monitor Distro is a distribution of the .NET OpenTelemetry SDK with in
   * **HTTP Client Instrumentation**: Provides automatic tracing for outgoing HTTP requests made using [System.Net.Http.HttpClient](https://docs.microsoft.com/dotnet/api/system.net.http.httpclient).
   * **SQL Client Instrumentation** Provides automatic tracing for SQL queries executed using the [Microsoft.Data.SqlClient](https://www.nuget.org/packages/Microsoft.Data.SqlClient) and [System.Data.SqlClient](https://www.nuget.org/packages/System.Data.SqlClient) packages. (While the OpenTelemetry SqlClient instrumentation remains in its beta phase, we have taken the step to vendor it and include it in our Distro)
 
-* Metrics
-  * Provides automatic collection of Application Insights Standard metrics.
+	* Metrics
+	  * **Application Insights Standard Metrics**: Provides automatic collection of Application Insights Standard metrics.
+	  * **Conditional Instrumentation for ASP.NET Core and HTTP Client Metrics**: To adapt to different .NET runtime environments and optimize telemetry collection, our distro now includes a dynamic approach to these instrumentations. Based on the .NET runtime version, we selectively enable metrics collection for ASP.NET Core and HTTP client activities:
+		* **.NET 8 and above**: Utilizes built-in Metrics `Microsoft.AspNetCore.Hosting` and `System.Net.Http` from the .NET. For a detailed list of metrics produced, refer to the [Microsoft.AspNetCore.Hosting](https://learn.microsoft.com/en-in/dotnet/core/diagnostics/built-in-metrics-aspnetcore#microsoftaspnetcorehosting) and [System.Net.Http](https://learn.microsoft.com/en-in/dotnet/core/diagnostics/built-in-metrics-system-net#systemnethttp) metrics documentation.
+		* **Below .NET 8**: Falls back to ASP.NET Core Instrumentation and HTTP Client Instrumentation for compatibility with older runtime versions. For a detailed list of metrics produced, refer to the [ASP.NET Core Instrumentation](https://github.com/open-telemetry/opentelemetry-dotnet/blob/main/src/OpenTelemetry.Instrumentation.AspNetCore/README.md) and [HTTP Client Instrumentation](https://github.com/open-telemetry/opentelemetry-dotnet/blob/main/src/OpenTelemetry.Instrumentation.Http/README.md) documentation.
 
 * [Logs](https://github.com/open-telemetry/opentelemetry-dotnet/tree/main/docs/logs/getting-started-console)
 
@@ -263,6 +266,23 @@ builder.Services.AddOpenTelemetry().UseAzureMonitor(o =>
 });
 ```
 
+#### Drop a Metrics Instrument
+
+If you want to exclude specific instruments from being collected in your application's telemetry, such as metrics from the distro or custom metrics, use the following code snippet. 
+
+```C#
+builder.Services.ConfigureOpenTelemetryMeterProvider(b =>
+    b.AddView((instrument) =>
+    {
+        if (instrument.Name == "http.server.request.duration")
+        {
+            return null;
+        }
+
+        return null;
+    }));
+```
+
 ## Key concepts
 
 The Azure Monitor Distro is a distribution package that facilitates users in sending telemetry data to Azure Monitor. It encompasses the .NET OpenTelemetry SDK and instrumentation libraries for ASP.NET Core, HttpClient, and SQLClient, ensuring seamless integration and data collection.

sdk/monitor/Azure.Monitor.OpenTelemetry.AspNetCore/src/OpenTelemetryBuilderExtensions.cs

@@ -118,6 +118,7 @@ public static OpenTelemetryBuilder UseAzureMonitor(this OpenTelemetryBuilder bui
                             .AddAzureMonitorTraceExporter());
 
             builder.WithMetrics(b => b
+                            .AddHttpServerAndClientMetrics()
                             .AddAzureMonitorMetricExporter());
 
             builder.Services.AddLogging(logging =>
@@ -217,5 +218,12 @@ private static TracerProviderBuilder AddVendorInstrumentationIfPackageNotReferen
 
             return tracerProviderBuilder;
         }
+
+        private static MeterProviderBuilder AddHttpServerAndClientMetrics(this MeterProviderBuilder meterProviderBuilder)
+        {
+            return Environment.Version.Major >= 8 ?
+                meterProviderBuilder.AddMeter("Microsoft.AspNetCore.Hosting").AddMeter("System.Net.Http")
+                : meterProviderBuilder.AddAspNetCoreInstrumentation().AddHttpClientInstrumentation();
+        }
     }
 }