Add disable HTTP metrics endpoint metadata

src/Hosting/Hosting/src/Internal/HostingApplicationDiagnostics.cs

@@ -154,11 +154,12 @@ public void RequestEnd(HttpContext httpContext, Exception? exception, HostingApp
 
             if (context.MetricsEnabled)
             {
+                Debug.Assert(context.MetricsTagsFeature != null, "MetricsTagsFeature should be set if MetricsEnabled is true.");
+
                 var endpoint = HttpExtensions.GetOriginalEndpoint(httpContext);
+                var disableHttpRequestDurationMetric = endpoint?.Metadata.GetMetadata<IDisableHttpMetricsMetadata>() != null || context.MetricsTagsFeature.MetricsDisabled;
                 var route = endpoint?.Metadata.GetMetadata<IRouteDiagnosticsMetadata>()?.Route;
 
-                Debug.Assert(context.MetricsTagsFeature != null, "MetricsTagsFeature should be set if MetricsEnabled is true.");
-
                 _metrics.RequestEnd(
                     context.MetricsTagsFeature.Protocol!,
                     context.MetricsTagsFeature.Scheme!,
@@ -169,7 +170,8 @@ public void RequestEnd(HttpContext httpContext, Exception? exception, HostingApp
                     exception,
                     context.MetricsTagsFeature.TagsList,
                     startTimestamp,
-                    currentTimestamp);
+                    currentTimestamp,
+                    disableHttpRequestDurationMetric);
             }
 
             if (reachedPipelineEnd)

src/Hosting/Hosting/src/Internal/HostingMetrics.cs

@@ -42,7 +42,7 @@ public void RequestStart(string scheme, string method)
         _activeRequestsCounter.Add(1, tags);
     }
 
-    public void RequestEnd(string protocol, string scheme, string method, string? route, int statusCode, bool unhandledRequest, Exception? exception, List<KeyValuePair<string, object?>>? customTags, long startTimestamp, long currentTimestamp)
+    public void RequestEnd(string protocol, string scheme, string method, string? route, int statusCode, bool unhandledRequest, Exception? exception, List<KeyValuePair<string, object?>>? customTags, long startTimestamp, long currentTimestamp, bool disableHttpRequestDurationMetric)
     {
         var tags = new TagList();
         InitializeRequestTags(ref tags, scheme, method);
@@ -53,7 +53,7 @@ public void RequestEnd(string protocol, string scheme, string method, string? ro
             _activeRequestsCounter.Add(-1, tags);
         }
 
-        if (_requestDuration.Enabled)
+        if (!disableHttpRequestDurationMetric && _requestDuration.Enabled)
         {
             if (TryGetHttpVersion(protocol, out var httpVersion))
             {

src/Hosting/Hosting/src/Internal/HttpMetricsTagsFeature.cs

@@ -8,6 +8,7 @@ namespace Microsoft.AspNetCore.Hosting;
 internal sealed class HttpMetricsTagsFeature : IHttpMetricsTagsFeature
 {
     ICollection<KeyValuePair<string, object?>> IHttpMetricsTagsFeature.Tags => TagsList;
+    public bool MetricsDisabled { get; set; }
 
     public List<KeyValuePair<string, object?>> TagsList { get; } = new List<KeyValuePair<string, object?>>();
 
@@ -20,6 +21,7 @@ internal sealed class HttpMetricsTagsFeature : IHttpMetricsTagsFeature
     public void Reset()
     {
         TagsList.Clear();
+        MetricsDisabled = false;
 
         Method = null;
         Scheme = null;

src/Hosting/Hosting/test/HostingApplicationDiagnosticsTests.cs

@@ -5,8 +5,10 @@
 using System.Diagnostics.Metrics;
 using System.Diagnostics.Tracing;
 using System.Reflection;
+using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Http.Features;
+using Microsoft.AspNetCore.Http.Metadata;
 using Microsoft.AspNetCore.Internal;
 using Microsoft.AspNetCore.InternalTesting;
 using Microsoft.Extensions.Diagnostics.Metrics;
@@ -228,7 +230,6 @@ public void Metrics_RequestChanges_OriginalValuesUsed()
 
         var testMeterFactory = new TestMeterFactory();
         using var activeRequestsCollector = new MetricCollector<long>(testMeterFactory, HostingMetrics.MeterName, "http.server.active_requests");
-        using var requestDurationCollector = new MetricCollector<double>(testMeterFactory, HostingMetrics.MeterName, "http.server.request.duration");
 
         // Act
         var hostingApplication = CreateApplication(out var features, eventSource: hostingEventSource, meterFactory: testMeterFactory, configure: c =>
@@ -279,6 +280,182 @@ public void Metrics_RequestChanges_OriginalValuesUsed()
         Assert.Null(context.MetricsTagsFeature.Protocol);
     }
 
+    [Fact]
+    public void Metrics_Route_RouteTagReported()
+    {
+        // Arrange
+        var hostingEventSource = new HostingEventSource(Guid.NewGuid().ToString());
+
+        var testMeterFactory = new TestMeterFactory();
+        using var activeRequestsCollector = new MetricCollector<long>(testMeterFactory, HostingMetrics.MeterName, "http.server.active_requests");
+        using var requestDurationCollector = new MetricCollector<double>(testMeterFactory, HostingMetrics.MeterName, "http.server.request.duration");
+
+        // Act
+        var hostingApplication = CreateApplication(out var features, eventSource: hostingEventSource, meterFactory: testMeterFactory, configure: c =>
+        {
+            c.Request.Protocol = "1.1";
+            c.Request.Scheme = "http";
+            c.Request.Method = "POST";
+            c.Request.Host = new HostString("localhost");
+            c.Request.Path = "/hello";
+            c.Request.ContentType = "text/plain";
+            c.Request.ContentLength = 1024;
+        });
+        var context = hostingApplication.CreateContext(features);
+
+        Assert.Collection(activeRequestsCollector.GetMeasurementSnapshot(),
+            m =>
+            {
+                Assert.Equal(1, m.Value);
+                Assert.Equal("http", m.Tags["url.scheme"]);
+                Assert.Equal("POST", m.Tags["http.request.method"]);
+            });
+
+        context.HttpContext.SetEndpoint(new Endpoint(
+            c => Task.CompletedTask,
+            new EndpointMetadataCollection(new TestRouteDiagnosticsMetadata()),
+            "Test endpoint"));
+
+        hostingApplication.DisposeContext(context, null);
+
+        // Assert
+        Assert.Collection(activeRequestsCollector.GetMeasurementSnapshot(),
+            m =>
+            {
+                Assert.Equal(1, m.Value);
+                Assert.Equal("http", m.Tags["url.scheme"]);
+                Assert.Equal("POST", m.Tags["http.request.method"]);
+            },
+            m =>
+            {
+                Assert.Equal(-1, m.Value);
+                Assert.Equal("http", m.Tags["url.scheme"]);
+                Assert.Equal("POST", m.Tags["http.request.method"]);
+            });
+        Assert.Collection(requestDurationCollector.GetMeasurementSnapshot(),
+            m =>
+            {
+                Assert.True(m.Value > 0);
+                Assert.Equal("hello/{name}", m.Tags["http.route"]);
+            });
+    }
+
+    [Fact]
+    public void Metrics_DisableHttpMetricsWithMetadata_NoMetrics()
+    {
+        // Arrange
+        var hostingEventSource = new HostingEventSource(Guid.NewGuid().ToString());
+
+        var testMeterFactory = new TestMeterFactory();
+        using var activeRequestsCollector = new MetricCollector<long>(testMeterFactory, HostingMetrics.MeterName, "http.server.active_requests");
+        using var requestDurationCollector = new MetricCollector<double>(testMeterFactory, HostingMetrics.MeterName, "http.server.request.duration");
+
+        // Act
+        var hostingApplication = CreateApplication(out var features, eventSource: hostingEventSource, meterFactory: testMeterFactory, configure: c =>
+        {
+            c.Request.Protocol = "1.1";
+            c.Request.Scheme = "http";
+            c.Request.Method = "POST";
+            c.Request.Host = new HostString("localhost");
+            c.Request.Path = "/hello";
+            c.Request.ContentType = "text/plain";
+            c.Request.ContentLength = 1024;
+        });
+        var context = hostingApplication.CreateContext(features);
+
+        Assert.Collection(activeRequestsCollector.GetMeasurementSnapshot(),
+            m =>
+            {
+                Assert.Equal(1, m.Value);
+                Assert.Equal("http", m.Tags["url.scheme"]);
+                Assert.Equal("POST", m.Tags["http.request.method"]);
+            });
+
+        context.HttpContext.SetEndpoint(new Endpoint(
+            c => Task.CompletedTask,
+            new EndpointMetadataCollection(new TestRouteDiagnosticsMetadata(), new DisableHttpMetricsAttribute()),
+            "Test endpoint"));
+
+        hostingApplication.DisposeContext(context, null);
+
+        // Assert
+        Assert.Collection(activeRequestsCollector.GetMeasurementSnapshot(),
+            m =>
+            {
+                Assert.Equal(1, m.Value);
+                Assert.Equal("http", m.Tags["url.scheme"]);
+                Assert.Equal("POST", m.Tags["http.request.method"]);
+            },
+            m =>
+            {
+                Assert.Equal(-1, m.Value);
+                Assert.Equal("http", m.Tags["url.scheme"]);
+                Assert.Equal("POST", m.Tags["http.request.method"]);
+            });
+        Assert.Empty(requestDurationCollector.GetMeasurementSnapshot());
+    }
+
+    [Fact]
+    public void Metrics_DisableHttpMetricsWithFeature_NoMetrics()
+    {
+        // Arrange
+        var hostingEventSource = new HostingEventSource(Guid.NewGuid().ToString());
+
+        var testMeterFactory = new TestMeterFactory();
+        using var activeRequestsCollector = new MetricCollector<long>(testMeterFactory, HostingMetrics.MeterName, "http.server.active_requests");
+        using var requestDurationCollector = new MetricCollector<double>(testMeterFactory, HostingMetrics.MeterName, "http.server.request.duration");
+
+        // Act
+        var hostingApplication = CreateApplication(out var features, eventSource: hostingEventSource, meterFactory: testMeterFactory, configure: c =>
+        {
+            c.Request.Protocol = "1.1";
+            c.Request.Scheme = "http";
+            c.Request.Method = "POST";
+            c.Request.Host = new HostString("localhost");
+            c.Request.Path = "/hello";
+            c.Request.ContentType = "text/plain";
+            c.Request.ContentLength = 1024;
+        });
+        var context = hostingApplication.CreateContext(features);
+
+        Assert.Collection(activeRequestsCollector.GetMeasurementSnapshot(),
+            m =>
+            {
+                Assert.Equal(1, m.Value);
+                Assert.Equal("http", m.Tags["url.scheme"]);
+                Assert.Equal("POST", m.Tags["http.request.method"]);
+            });
+
+        context.HttpContext.Features.Get<IHttpMetricsTagsFeature>().MetricsDisabled = true;
+
+        // Assert 1
+        Assert.True(context.MetricsTagsFeature.MetricsDisabled);
+
+        hostingApplication.DisposeContext(context, null);
+
+        // Assert 2
+        Assert.Collection(activeRequestsCollector.GetMeasurementSnapshot(),
+            m =>
+            {
+                Assert.Equal(1, m.Value);
+                Assert.Equal("http", m.Tags["url.scheme"]);
+                Assert.Equal("POST", m.Tags["http.request.method"]);
+            },
+            m =>
+            {
+                Assert.Equal(-1, m.Value);
+                Assert.Equal("http", m.Tags["url.scheme"]);
+                Assert.Equal("POST", m.Tags["http.request.method"]);
+            });
+        Assert.Empty(requestDurationCollector.GetMeasurementSnapshot());
+        Assert.False(context.MetricsTagsFeature.MetricsDisabled);
+    }
+
+    private sealed class TestRouteDiagnosticsMetadata : IRouteDiagnosticsMetadata
+    {
+        public string Route { get; } = "hello/{name}";
+    }
+
     [Fact]
     public void DisposeContextDoesNotThrowWhenContextScopeIsNull()
     {

src/Hosting/Hosting/test/HostingMetricsTests.cs

@@ -180,6 +180,7 @@ public void IHttpMetricsTagsFeatureNotUsedFromFeatureCollection()
     private sealed class TestHttpMetricsTagsFeature : IHttpMetricsTagsFeature
     {
         public ICollection<KeyValuePair<string, object>> Tags { get; } = new Collection<KeyValuePair<string, object>>();
+        public bool MetricsDisabled { get; set; }
     }
 
     private static HostingApplication CreateApplication(IHttpContextFactory httpContextFactory = null, bool useHttpContextAccessor = false,

src/Http/Http.Abstractions/src/Metadata/IDisableHttpMetricsMetadata.cs

@@ -0,0 +1,11 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.AspNetCore.Http.Metadata;
+
+/// <summary>
+/// A marker interface which can be used to identify metadata that disables HTTP request duration metrics.
+/// </summary>
+public interface IDisableHttpMetricsMetadata
+{
+}

src/Http/Http.Abstractions/src/PublicAPI.Unshipped.txt

@@ -4,3 +4,4 @@ Microsoft.AspNetCore.Http.HostString.HostString(string? value) -> void
 *REMOVED*Microsoft.AspNetCore.Http.HostString.Value.get -> string!
 Microsoft.AspNetCore.Http.HostString.Value.get -> string?
 Microsoft.AspNetCore.Http.HttpValidationProblemDetails.HttpValidationProblemDetails(System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<string!, string![]!>>! errors) -> void
+Microsoft.AspNetCore.Http.Metadata.IDisableHttpMetricsMetadata

src/Http/Http.Extensions/src/DisableHttpMetricsAttribute.cs

@@ -0,0 +1,14 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Microsoft.AspNetCore.Http.Metadata;
+
+namespace Microsoft.AspNetCore.Http;
+
+/// <summary>
+/// Specifies that HTTP request duration metrics is disabled for an endpoint.
+/// </summary>
+[AttributeUsage(AttributeTargets.Method | AttributeTargets.Class)]
+public sealed class DisableHttpMetricsAttribute : Attribute, IDisableHttpMetricsMetadata
+{
+}

src/Http/Http.Extensions/src/HttpMetricsEndpointConventionBuilderExtensions.cs

@@ -0,0 +1,24 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Microsoft.AspNetCore.Http;
+
+namespace Microsoft.AspNetCore.Builder;
+
+/// <summary>
+/// HTTP metrics extension methods for <see cref="IEndpointConventionBuilder"/>.
+/// </summary>
+public static class HttpMetricsEndpointConventionBuilderExtensions
+{
+    /// <summary>
+    /// Specifies that HTTP request duration metrics is disabled for an endpoint.
+    /// </summary>
+    /// <typeparam name="TBuilder">The type of endpoint convention builder.</typeparam>
+    /// <param name="builder">The endpoint convention builder.</param>
+    /// <returns>The original convention builder parameter.</returns>
+    public static TBuilder DisableHttpMetrics<TBuilder>(this TBuilder builder) where TBuilder : IEndpointConventionBuilder
+    {
+        builder.Add(b => b.Metadata.Add(new DisableHttpMetricsAttribute()));
+        return builder;
+    }
+}

src/Http/Http.Extensions/src/PublicAPI.Unshipped.txt

@@ -1,2 +1,6 @@
 #nullable enable
 Microsoft.AspNetCore.Http.HttpValidationProblemDetails.HttpValidationProblemDetails(System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<string!, string![]!>>! errors) -> void (forwarded, contained in Microsoft.AspNetCore.Http.Abstractions)
+Microsoft.AspNetCore.Builder.HttpMetricsEndpointConventionBuilderExtensions
+Microsoft.AspNetCore.Http.DisableHttpMetricsAttribute
+Microsoft.AspNetCore.Http.DisableHttpMetricsAttribute.DisableHttpMetricsAttribute() -> void
+static Microsoft.AspNetCore.Builder.HttpMetricsEndpointConventionBuilderExtensions.DisableHttpMetrics<TBuilder>(this TBuilder builder) -> TBuilder

src/Http/Http.Features/src/IHttpMetricsTagsFeature.cs

@@ -4,12 +4,18 @@
 namespace Microsoft.AspNetCore.Http.Features;
 
 /// <summary>
-/// Provides access to tags added to the metrics HTTP request counter. This feature isn't set if the counter isn't enabled.
+/// Provides access to tags added to HTTP request duration metrics. This feature isn't set if the counter isn't enabled.
 /// </summary>
 public interface IHttpMetricsTagsFeature
 {
     /// <summary>
     /// Gets the tag collection.
     /// </summary>
     ICollection<KeyValuePair<string, object?>> Tags { get; }
+
+    // MetricsDisabled was added after the initial release of this interface and is intentionally a DIM property.
+    /// <summary>
+    /// Gets or sets a flag that disables recording HTTP request duration metrics for the current HTTP request.
+    /// </summary>
+    public bool MetricsDisabled { get; set; }
 }

src/Http/Http.Features/src/PublicAPI.Unshipped.txt

@@ -1 +1,3 @@
 #nullable enable
+Microsoft.AspNetCore.Http.Features.IHttpMetricsTagsFeature.MetricsDisabled.get -> bool
+Microsoft.AspNetCore.Http.Features.IHttpMetricsTagsFeature.MetricsDisabled.set -> void

src/Http/Routing/src/EndpointNameAttribute.cs

@@ -1,4 +1,4 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using Microsoft.AspNetCore.Http;