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

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

@@ -4,6 +4,17 @@
 
 ### Features Added
 
+* Added ASP.NET Core and HTTP Client Metrics Collection:
+  * For `.NET 8.0` and above, we now utilize built-in Metrics from
+    [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 targetting `.NET 7.0` and below, distro uses ASP.NET Core and HTTP Client Instrumentation.
+    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#list-of-metrics-produced)
+    and [HTTP Client Instrumentation](https://github.com/open-telemetry/opentelemetry-dotnet/blob/main/src/OpenTelemetry.Instrumentation.Http/README.md#list-of-metrics-produced)
+    documentation.
+  ([#42307](https://github.com/Azure/azure-sdk-for-net/pull/42307))
+
 - Enabled support for log collection from Azure SDKs via `Microsoft.Extensions.Logging`. See [Logging with the Azure SDK for .NET](https://learn.microsoft.com/dotnet/azure/sdk/logging)
   for the details.
   ([#42374](https://github.com/Azure/azure-sdk-for-net/pull/42374))

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

@@ -20,7 +20,10 @@ The Azure Monitor Distro is a distribution of the .NET OpenTelemetry SDK with in
   * **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.
+  * **Application Insights Standard Metrics**: Provides automatic collection of Application Insights Standard metrics.
+  * **ASP.NET Core and HTTP Client Metrics Instrumentation**: 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 requests:
+	* **.NET 8.0 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.
+	* **.NET 7.0 and below**: 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#list-of-metrics-produced) and [HTTP Client Instrumentation](https://github.com/open-telemetry/opentelemetry-dotnet/blob/main/src/OpenTelemetry.Instrumentation.Http/README.md#list-of-metrics-produced) documentation.
 
 * [Logs](https://github.com/open-telemetry/opentelemetry-dotnet/tree/main/docs/logs/getting-started-console)
   * Logs created with `Microsoft.Extensions.Logging`. See [Logging in .NET Core and ASP.NET Core](https://learn.microsoft.com/aspnet/core/fundamentals/logging) for more details on how to create and configure logging.
@@ -265,6 +268,19 @@ builder.Services.AddOpenTelemetry().UseAzureMonitor(o =>
 });
 ```
 
+#### Drop a Metrics Instrument
+
+The Azure Monitor Distro enables metric collection and collects several metrics by default.
+If you want to exclude specific instruments from being collected in your application's telemetry use the following code snippet:
+
+```C#
+builder.Services.ConfigureOpenTelemetryMeterProvider(metrics =>
+    metrics.AddView(instrumentName: "http.server.active_requests", MetricStreamConfiguration.Drop)
+    );
+```
+
+Refer to [Drop an instrument](https://github.com/open-telemetry/opentelemetry-dotnet/tree/main/docs/metrics/customizing-the-sdk#drop-an-instrument) for more examples.
+
 ## 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

@@ -119,6 +119,7 @@ public static OpenTelemetryBuilder UseAzureMonitor(this OpenTelemetryBuilder bui
                             .AddAzureMonitorTraceExporter());
 
             builder.WithMetrics(b => b
+                            .AddHttpClientAndServerMetrics()
                             .AddAzureMonitorMetricExporter());
 
             builder.Services.AddLogging(logging =>
@@ -233,5 +234,12 @@ private static TracerProviderBuilder AddVendorInstrumentationIfPackageNotReferen
 
             return tracerProviderBuilder;
         }
+
+        private static MeterProviderBuilder AddHttpClientAndServerMetrics(this MeterProviderBuilder meterProviderBuilder)
+        {
+            return Environment.Version.Major >= 8 ?
+                meterProviderBuilder.AddMeter("Microsoft.AspNetCore.Hosting").AddMeter("System.Net.Http")
+                : meterProviderBuilder.AddAspNetCoreInstrumentation().AddHttpClientInstrumentation();
+        }
     }
 }