Annotate histograms with bucket boundaries

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

@@ -29,7 +29,8 @@ public HostingMetrics(IMeterFactory meterFactory)
         _requestDuration = _meter.CreateHistogram<double>(
             "http.server.request.duration",
             unit: "s",
-            description: "Duration of HTTP server requests.");
+            description: "Duration of HTTP server requests.",
+            advice: new InstrumentAdvice<double> { HistogramBucketBoundaries = MetricsConstants.ShortSecondsBucketBoundaries });
     }
 
     // Note: Calling code checks whether counter is enabled.

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

@@ -17,6 +17,7 @@
     <Compile Include="$(SharedSourceRoot)ErrorPage\**\*.cs" />
     <Compile Include="$(SharedSourceRoot)StaticWebAssets\**\*.cs" LinkBase="StaticWebAssets" />
     <Compile Include="$(SharedSourceRoot)Metrics\MetricsExtensions.cs" />
+    <Compile Include="$(SharedSourceRoot)Metrics\MetricsConstants.cs" />
   </ItemGroup>
 
   <ItemGroup>

src/Middleware/RateLimiting/src/Microsoft.AspNetCore.RateLimiting.csproj

@@ -18,6 +18,7 @@
     <Reference Include="System.Threading.RateLimiting" />
 
     <Compile Include="$(SharedSourceRoot)ValueStopwatch\*.cs" />
+    <Compile Include="$(SharedSourceRoot)Metrics\MetricsConstants.cs" />
   </ItemGroup>
 
   <ItemGroup>

src/Middleware/RateLimiting/src/RateLimitingMetrics.cs

@@ -4,6 +4,7 @@
 using System.Diagnostics;
 using System.Diagnostics.Metrics;
 using System.Runtime.CompilerServices;
+using Microsoft.AspNetCore.Http;
 
 namespace Microsoft.AspNetCore.RateLimiting;
 
@@ -30,7 +31,8 @@ public RateLimitingMetrics(IMeterFactory meterFactory)
         _requestLeaseDurationCounter = _meter.CreateHistogram<double>(
             "aspnetcore.rate_limiting.request_lease.duration",
             unit: "s",
-            description: "The duration of rate limiting leases held by HTTP requests on the server.");
+            description: "The duration of rate limiting leases held by HTTP requests on the server.",
+            advice: new InstrumentAdvice<double> { HistogramBucketBoundaries = MetricsConstants.ShortSecondsBucketBoundaries });
 
         _queuedRequestsCounter = _meter.CreateUpDownCounter<long>(
             "aspnetcore.rate_limiting.queued_requests",
@@ -40,7 +42,8 @@ public RateLimitingMetrics(IMeterFactory meterFactory)
         _queuedRequestDurationCounter = _meter.CreateHistogram<double>(
             "aspnetcore.rate_limiting.request.time_in_queue",
             unit: "s",
-            description: "The duration of HTTP requests in a queue, waiting to acquire a rate limiting lease.");
+            description: "The duration of HTTP requests in a queue, waiting to acquire a rate limiting lease.",
+            advice: new InstrumentAdvice<double> { HistogramBucketBoundaries = MetricsConstants.ShortSecondsBucketBoundaries });
 
         _requestsCounter = _meter.CreateCounter<long>(
             "aspnetcore.rate_limiting.requests",

src/Servers/Kestrel/Core/src/Internal/Infrastructure/KestrelMetrics.cs

@@ -9,6 +9,7 @@
 using System.Runtime.CompilerServices;
 using System.Security.Authentication;
 using Microsoft.AspNetCore.Connections;
+using Microsoft.AspNetCore.Http;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure;
 
@@ -43,7 +44,8 @@ public KestrelMetrics(IMeterFactory meterFactory)
         _connectionDuration = _meter.CreateHistogram<double>(
             "kestrel.connection.duration",
             unit: "s",
-            description: "The duration of connections on the server.");
+            description: "The duration of connections on the server.",
+            advice: new InstrumentAdvice<double> { HistogramBucketBoundaries = MetricsConstants.LongSecondsBucketBoundaries });
 
         _rejectedConnectionsCounter = _meter.CreateCounter<long>(
            "kestrel.rejected_connections",
@@ -68,7 +70,8 @@ public KestrelMetrics(IMeterFactory meterFactory)
         _tlsHandshakeDuration = _meter.CreateHistogram<double>(
             "kestrel.tls_handshake.duration",
             unit: "s",
-            description: "The duration of TLS handshakes on the server.");
+            description: "The duration of TLS handshakes on the server.",
+            advice: new InstrumentAdvice<double> { HistogramBucketBoundaries = MetricsConstants.ShortSecondsBucketBoundaries });
 
         _activeTlsHandshakesCounter = _meter.CreateUpDownCounter<long>(
            "kestrel.active_tls_handshakes",

src/Servers/Kestrel/Core/src/Microsoft.AspNetCore.Server.Kestrel.Core.csproj

@@ -32,6 +32,7 @@
     <Compile Include="$(SharedSourceRoot)CancellationTokenSourcePool.cs" />
     <Compile Include="$(SharedSourceRoot)Debugger\DictionaryItemDebugView.cs" LinkBase="Shared" />
     <Compile Include="$(SharedSourceRoot)Debugger\StringValuesDictionaryDebugView.cs" LinkBase="Shared" />
+    <Compile Include="$(SharedSourceRoot)Metrics\MetricsConstants.cs" LinkBase="Shared" />
     <Compile Include="$(RepoRoot)src\Shared\TaskToApm.cs" Link="Internal\TaskToApm.cs" />
   </ItemGroup>
 

src/Shared/Metrics/MetricsConstants.cs

@@ -0,0 +1,13 @@
+// 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;
+
+internal static class MetricsConstants
+{
+    // Follows boundaries from http.server.request.duration/http.client.request.duration
+    public static readonly IReadOnlyList<double> ShortSecondsBucketBoundaries = [0.005, 0.01, 0.025, 0.05, 0.075, 0.1, 0.25, 0.5, 0.75, 1, 2.5, 5, 7.5, 10];
+
+    // Not based on a standard. Larger bucket sizes for longer lasting operations, e.g. HTTP connection duration. See https://github.com/open-telemetry/semantic-conventions/issues/336
+    public static readonly IReadOnlyList<double> LongSecondsBucketBoundaries = [0.01, 0.02, 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10, 30, 60, 120, 300];
+}

src/SignalR/common/Http.Connections/src/Internal/HttpConnectionsMetrics.cs

@@ -33,7 +33,8 @@ public HttpConnectionsMetrics(IMeterFactory meterFactory)
         _connectionDuration = _meter.CreateHistogram<double>(
             "signalr.server.connection.duration",
             unit: "s",
-            description: "The duration of connections on the server.");
+            description: "The duration of connections on the server.",
+            advice: new InstrumentAdvice<double> { HistogramBucketBoundaries = MetricsConstants.LongSecondsBucketBoundaries });
 
         _currentConnectionsCounter = _meter.CreateUpDownCounter<long>(
             "signalr.server.active_connections",

src/SignalR/common/Http.Connections/src/Microsoft.AspNetCore.Http.Connections.csproj

@@ -25,6 +25,7 @@
     <Compile Include="$(SharedSourceRoot)WebEncoders\**\*.cs" />
     <Compile Include="$(SharedSourceRoot)ValueTaskExtensions\**\*.cs" />
     <Compile Include="$(SharedSourceRoot)NonCapturingTimer\*.cs" />
+    <Compile Include="$(SharedSourceRoot)Metrics\MetricsConstants.cs" />
     <Compile Include="$(SharedSourceRoot)ThrowHelpers\ArgumentNullThrowHelper.cs" LinkBase="Shared" />
     <Compile Include="$(SharedSourceRoot)ThrowHelpers\ArgumentOutOfRangeThrowHelper.cs" LinkBase="Shared" />
     <Compile Include="$(SharedSourceRoot)CallerArgument\CallerArgumentExpressionAttribute.cs" LinkBase="Shared" />