Add metrics to ASP.NET Core

src/Hosting/Abstractions/src/Microsoft.AspNetCore.Hosting.Abstractions.csproj

@@ -11,6 +11,28 @@
     <IsTrimmable>true</IsTrimmable>
   </PropertyGroup>
 
+  <ItemGroup>
+    <Compile Include="$(SharedSourceRoot)Metrics\**\*.cs" LinkBase="Metrics" />
+  </ItemGroup>
+
+  <!-- Temporary hack to make prototype Metrics DI integration types available -->
+  <!-- TODO: Remove when Metrics DI intergration package is available https://github.com/dotnet/aspnetcore/issues/47618 -->
+  <ItemGroup>
+    <InternalsVisibleTo Include="Microsoft.AspNetCore.Hosting" />
+    <InternalsVisibleTo Include="Microsoft.AspNetCore.Hosting.Tests" />
+    <InternalsVisibleTo Include="Microsoft.AspNetCore.Server.Kestrel.Core" />
+    <InternalsVisibleTo Include="Microsoft.AspNetCore.Server.Kestrel.Core.Tests" />
+    <InternalsVisibleTo Include="Microsoft.AspNetCore.Server.Kestrel.Tests" />
+    <InternalsVisibleTo Include="InMemory.FunctionalTests" />
+    <InternalsVisibleTo Include="Sockets.BindTests" />
+    <InternalsVisibleTo Include="Sockets.FunctionalTests" />
+    <InternalsVisibleTo Include="Microsoft.AspNetCore.Server.Kestrel.Microbenchmarks" />
+    <InternalsVisibleTo Include="Microsoft.AspNetCore.Http.Connections" />
+    <InternalsVisibleTo Include="Microsoft.AspNetCore.Http.Connections.Tests" />
+    <InternalsVisibleTo Include="Microsoft.AspNetCore.SignalR" />
+    <InternalsVisibleTo Include="Microsoft.AspNetCore.Diagnostics.Tests" />
+  </ItemGroup>
+
   <ItemGroup>
     <Reference Include="Microsoft.AspNetCore.Hosting.Server.Abstractions" />
     <Reference Include="Microsoft.AspNetCore.Http.Abstractions" />

src/Hosting/Hosting/src/GenericHost/GenericWebHostBuilder.cs

@@ -62,12 +62,12 @@ public GenericWebHostBuilder(IHostBuilder builder, WebHostBuilderOptions options
 #pragma warning restore CS0618 // Type or member is obsolete
 
             services.Configure<GenericWebHostServiceOptions>(options =>
-        {
-            // Set the options
-            options.WebHostOptions = webHostOptions;
-            // Store and forward any startup errors
-            options.HostingStartupExceptions = _hostingStartupErrors;
-        });
+            {
+                // Set the options
+                options.WebHostOptions = webHostOptions;
+                // Store and forward any startup errors
+                options.HostingStartupExceptions = _hostingStartupErrors;
+            });
 
             // REVIEW: This is bad since we don't own this type. Anybody could add one of these and it would mess things up
             // We need to flow this differently
@@ -80,6 +80,9 @@ public GenericWebHostBuilder(IHostBuilder builder, WebHostBuilderOptions options
             services.TryAddScoped<IMiddlewareFactory, MiddlewareFactory>();
             services.TryAddSingleton<IApplicationBuilderFactory, ApplicationBuilderFactory>();
 
+            services.AddMetrics();
+            services.TryAddSingleton<HostingMetrics>();
+
             // IMPORTANT: This needs to run *before* direct calls on the builder (like UseStartup)
             _hostingStartupWebHostBuilder?.ConfigureServices(webhostContext, services);
 

src/Hosting/Hosting/src/GenericHost/GenericWebHostService.cs

@@ -26,7 +26,8 @@ internal sealed partial class GenericWebHostService : IHostedService
                                  IApplicationBuilderFactory applicationBuilderFactory,
                                  IEnumerable<IStartupFilter> startupFilters,
                                  IConfiguration configuration,
-                                 IWebHostEnvironment hostingEnvironment)
+                                 IWebHostEnvironment hostingEnvironment,
+                                 HostingMetrics hostingMetrics)
     {
         Options = options.Value;
         Server = server;
@@ -40,6 +41,7 @@ internal sealed partial class GenericWebHostService : IHostedService
         StartupFilters = startupFilters;
         Configuration = configuration;
         HostingEnvironment = hostingEnvironment;
+        HostingMetrics = hostingMetrics;
     }
 
     public GenericWebHostServiceOptions Options { get; }
@@ -55,6 +57,7 @@ internal sealed partial class GenericWebHostService : IHostedService
     public IEnumerable<IStartupFilter> StartupFilters { get; }
     public IConfiguration Configuration { get; }
     public IWebHostEnvironment HostingEnvironment { get; }
+    public HostingMetrics HostingMetrics { get; }
 
     public async Task StartAsync(CancellationToken cancellationToken)
     {
@@ -153,7 +156,7 @@ static string ExpandPorts(string ports, string scheme)
             application = ErrorPageBuilder.BuildErrorPageApplication(HostingEnvironment.ContentRootFileProvider, Logger, showDetailedErrors, ex);
         }
 
-        var httpApplication = new HostingApplication(application, Logger, DiagnosticListener, ActivitySource, Propagator, HttpContextFactory);
+        var httpApplication = new HostingApplication(application, Logger, DiagnosticListener, ActivitySource, Propagator, HttpContextFactory, HostingEventSource.Log, HostingMetrics);
 
         await Server.StartAsync(httpApplication, cancellationToken);
         HostingEventSource.Log.ServerReady();

src/Hosting/Hosting/src/GenericHost/SlimWebHostBuilder.cs

@@ -53,6 +53,9 @@ public SlimWebHostBuilder(IHostBuilder builder, WebHostBuilderOptions options)
             services.TryAddSingleton<IHttpContextFactory, DefaultHttpContextFactory>();
             services.TryAddScoped<IMiddlewareFactory, MiddlewareFactory>();
             services.TryAddSingleton<IApplicationBuilderFactory, ApplicationBuilderFactory>();
+
+            services.AddMetrics();
+            services.TryAddSingleton<HostingMetrics>();
         });
     }
 

src/Hosting/Hosting/src/Internal/HostingApplication.cs

@@ -23,10 +23,12 @@ internal sealed class HostingApplication : IHttpApplication<HostingApplication.C
         DiagnosticListener diagnosticSource,
         ActivitySource activitySource,
         DistributedContextPropagator propagator,
-        IHttpContextFactory httpContextFactory)
+        IHttpContextFactory httpContextFactory,
+        HostingEventSource eventSource,
+        HostingMetrics metrics)
     {
         _application = application;
-        _diagnostics = new HostingApplicationDiagnostics(logger, diagnosticSource, activitySource, propagator);
+        _diagnostics = new HostingApplicationDiagnostics(logger, diagnosticSource, activitySource, propagator, eventSource, metrics);
         if (httpContextFactory is DefaultHttpContextFactory factory)
         {
             _defaultHttpContextFactory = factory;
@@ -110,7 +112,7 @@ public void DisposeContext(Context context, Exception? exception)
             _httpContextFactory!.Dispose(httpContext);
         }
 
-        HostingApplicationDiagnostics.ContextDisposed(context);
+        _diagnostics.ContextDisposed(context);
 
         // Reset the context as it may be pooled
         context.Reset();
@@ -139,9 +141,10 @@ internal sealed class Context
 
         public long StartTimestamp { get; set; }
         internal bool HasDiagnosticListener { get; set; }
-        public bool EventLogEnabled { get; set; }
+        public bool EventLogOrMetricsEnabled { get; set; }
 
         internal IHttpActivityFeature? HttpActivityFeature;
+        internal HttpMetricsTagsFeature? MetricsTagsFeature;
 
         public void Reset()
         {
@@ -153,7 +156,8 @@ public void Reset()
 
             StartTimestamp = 0;
             HasDiagnosticListener = false;
-            EventLogEnabled = false;
+            EventLogOrMetricsEnabled = false;
+            MetricsTagsFeature?.Tags.Clear();
         }
     }
 }

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

@@ -8,14 +8,13 @@
 using System.Runtime.CompilerServices;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Http.Features;
+using Microsoft.AspNetCore.Http.Metadata;
 using Microsoft.Extensions.Logging;
 
 namespace Microsoft.AspNetCore.Hosting;
 
 internal sealed class HostingApplicationDiagnostics
 {
-    private static readonly double TimestampToTicks = TimeSpan.TicksPerSecond / (double)Stopwatch.Frequency;
-
     // internal so it can be used in tests
     internal const string ActivityName = "Microsoft.AspNetCore.Hosting.HttpRequestIn";
     private const string ActivityStartKey = ActivityName + ".Start";
@@ -28,28 +27,46 @@ internal sealed class HostingApplicationDiagnostics
     private readonly ActivitySource _activitySource;
     private readonly DiagnosticListener _diagnosticListener;
     private readonly DistributedContextPropagator _propagator;
+    private readonly HostingEventSource _eventSource;
+    private readonly HostingMetrics _metrics;
     private readonly ILogger _logger;
 
     public HostingApplicationDiagnostics(
         ILogger logger,
         DiagnosticListener diagnosticListener,
         ActivitySource activitySource,
-        DistributedContextPropagator propagator)
+        DistributedContextPropagator propagator,
+        HostingEventSource eventSource,
+        HostingMetrics metrics)
     {
         _logger = logger;
         _diagnosticListener = diagnosticListener;
         _activitySource = activitySource;
         _propagator = propagator;
+        _eventSource = eventSource;
+        _metrics = metrics;
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public void BeginRequest(HttpContext httpContext, HostingApplication.Context context)
     {
         long startTimestamp = 0;
 
-        if (HostingEventSource.Log.IsEnabled())
+        if (_eventSource.IsEnabled() || _metrics.IsEnabled())
         {
-            context.EventLogEnabled = true;
+            context.EventLogOrMetricsEnabled = true;
+            if (httpContext.Features.Get<IHttpMetricsTagsFeature>() is HttpMetricsTagsFeature feature)
+            {
+                context.MetricsTagsFeature = feature;
+            }
+            else
+            {
+                context.MetricsTagsFeature ??= new HttpMetricsTagsFeature();
+                httpContext.Features.Set<IHttpMetricsTagsFeature>(context.MetricsTagsFeature);
+            }
+
+            startTimestamp = Stopwatch.GetTimestamp();
+
             // To keep the hot path short we defer logging in this function to non-inlines
             RecordRequestStartEventLog(httpContext);
         }
@@ -80,7 +97,11 @@ public void BeginRequest(HttpContext httpContext, HostingApplication.Context con
         {
             if (_diagnosticListener.IsEnabled(DeprecatedDiagnosticsBeginRequestKey))
             {
-                startTimestamp = Stopwatch.GetTimestamp();
+                if (startTimestamp == 0)
+                {
+                    startTimestamp = Stopwatch.GetTimestamp();
+                }
+
                 RecordBeginRequestDiagnostics(httpContext, startTimestamp);
             }
         }
@@ -121,6 +142,25 @@ public void RequestEnd(HttpContext httpContext, Exception? exception, HostingApp
             currentTimestamp = Stopwatch.GetTimestamp();
             // Non-inline
             LogRequestFinished(context, startTimestamp, currentTimestamp);
+
+            if (context.EventLogOrMetricsEnabled)
+            {
+                var route = httpContext.GetEndpoint()?.Metadata.GetMetadata<IRouteDiagnosticsMetadata>()?.Route;
+                var customTags = context.MetricsTagsFeature?.TagsList;
+
+                _metrics.RequestEnd(
+                    httpContext.Request.Protocol,
+                    httpContext.Request.IsHttps,
+                    httpContext.Request.Scheme,
+                    httpContext.Request.Method,
+                    httpContext.Request.Host,
+                    route,
+                    httpContext.Response.StatusCode,
+                    exception,
+                    customTags,
+                    startTimestamp,
+                    currentTimestamp);
+            }
         }
 
         if (_diagnosticListener.IsEnabled())
@@ -159,18 +199,18 @@ public void RequestEnd(HttpContext httpContext, Exception? exception, HostingApp
             StopActivity(httpContext, activity, context.HasDiagnosticListener);
         }
 
-        if (context.EventLogEnabled)
+        if (context.EventLogOrMetricsEnabled)
         {
             if (exception != null)
             {
                 // Non-inline
-                HostingEventSource.Log.UnhandledException();
+                _eventSource.UnhandledException();
             }
 
             // Count 500 as failed requests
             if (httpContext.Response.StatusCode >= 500)
             {
-                HostingEventSource.Log.RequestFailed();
+                _eventSource.RequestFailed();
             }
         }
 
@@ -179,12 +219,11 @@ public void RequestEnd(HttpContext httpContext, Exception? exception, HostingApp
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public static void ContextDisposed(HostingApplication.Context context)
+    public void ContextDisposed(HostingApplication.Context context)
     {
-        if (context.EventLogEnabled)
+        if (context.EventLogOrMetricsEnabled)
         {
-            // Non-inline
-            HostingEventSource.Log.RequestStop();
+            _eventSource.RequestStop();
         }
     }
 
@@ -211,7 +250,7 @@ private void LogRequestFinished(HostingApplication.Context context, long startTi
         // so check if we logged the start event
         if (context.StartLog != null)
         {
-            var elapsed = new TimeSpan((long)(TimestampToTicks * (currentTimestamp - startTimestamp)));
+            var elapsed = Stopwatch.GetElapsedTime(startTimestamp, currentTimestamp);
 
             _logger.Log(
                 logLevel: LogLevel.Information,
@@ -302,9 +341,10 @@ internal UnhandledExceptionData(HttpContext httpContext, long timestamp, Excepti
     }
 
     [MethodImpl(MethodImplOptions.NoInlining)]
-    private static void RecordRequestStartEventLog(HttpContext httpContext)
+    private void RecordRequestStartEventLog(HttpContext httpContext)
     {
-        HostingEventSource.Log.RequestStart(httpContext.Request.Method, httpContext.Request.Path);
+        _metrics.RequestStart(httpContext.Request.IsHttps, httpContext.Request.Scheme, httpContext.Request.Method, httpContext.Request.Host);
+        _eventSource.RequestStart(httpContext.Request.Method, httpContext.Request.Path);
     }
 
     [MethodImpl(MethodImplOptions.NoInlining)]

src/Hosting/Hosting/src/Internal/HostingEventSource.cs

@@ -20,7 +20,7 @@ internal sealed class HostingEventSource : EventSource
     private long _failedRequests;
 
     internal HostingEventSource()
-        : this("Microsoft.AspNetCore.Hosting")
+        : base("Microsoft.AspNetCore.Hosting", EventSourceSettings.EtwManifestEventFormat)
     {
     }
 
@@ -78,6 +78,7 @@ public void ServerReady()
         WriteEvent(6);
     }
 
+    [NonEvent]
     internal void RequestFailed()
     {
         Interlocked.Increment(ref _failedRequests);