Add HttpClient metrics for .NET Framework

src/OpenTelemetry.Instrumentation.Http/.publicApi/net462/PublicAPI.Unshipped.txt

@@ -19,6 +19,7 @@ OpenTelemetry.Instrumentation.Http.HttpClientInstrumentationOptions.RecordExcept
 OpenTelemetry.Metrics.MeterProviderBuilderExtensions
 OpenTelemetry.Trace.TracerProviderBuilderExtensions
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddHttpClientInstrumentation(this OpenTelemetry.Metrics.MeterProviderBuilder builder) -> OpenTelemetry.Metrics.MeterProviderBuilder
+static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddHttpClientInstrumentation(this OpenTelemetry.Metrics.MeterProviderBuilder builder, string name) -> OpenTelemetry.Metrics.MeterProviderBuilder
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddHttpClientInstrumentation(this OpenTelemetry.Trace.TracerProviderBuilder builder) -> OpenTelemetry.Trace.TracerProviderBuilder
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddHttpClientInstrumentation(this OpenTelemetry.Trace.TracerProviderBuilder builder, string name, System.Action<OpenTelemetry.Instrumentation.Http.HttpClientInstrumentationOptions> configureHttpClientInstrumentationOptions) -> OpenTelemetry.Trace.TracerProviderBuilder
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddHttpClientInstrumentation(this OpenTelemetry.Trace.TracerProviderBuilder builder, System.Action<OpenTelemetry.Instrumentation.Http.HttpClientInstrumentationOptions> configureHttpClientInstrumentationOptions) -> OpenTelemetry.Trace.TracerProviderBuilder

src/OpenTelemetry.Instrumentation.Http/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+* Added support for exposing `http.client.duration` on .NET Framework for `HttpWebRequest`, including `HttpClient`. Metrics support requires tracing to be enabled via `AddHttpClientInstrumentation` (#4768)[https://github.com/open-telemetry/opentelemetry-dotnet/pull/4768]
+
 ## 1.5.1-beta.1
 
 Released 2023-Jul-20

src/OpenTelemetry.Instrumentation.Http/Implementation/HttpWebRequestActivitySource.netfx.cs

@@ -17,6 +17,7 @@
 #if NETFRAMEWORK
 using System.Collections;
 using System.Diagnostics;
+using System.Diagnostics.Metrics;
 using System.Net;
 using System.Reflection;
 using System.Reflection.Emit;
@@ -39,13 +40,17 @@ internal static class HttpWebRequestActivitySource
     internal static readonly AssemblyName AssemblyName = typeof(HttpWebRequestActivitySource).Assembly.GetName();
     internal static readonly string ActivitySourceName = AssemblyName.Name + ".HttpWebRequest";
     internal static readonly string ActivityName = ActivitySourceName + ".HttpRequestOut";
+    internal static readonly string InstrumentationName = AssemblyName.Name;
 
     internal static readonly Func<HttpWebRequest, string, IEnumerable<string>> HttpWebRequestHeaderValuesGetter = (request, name) => request.Headers.GetValues(name);
     internal static readonly Action<HttpWebRequest, string, string> HttpWebRequestHeaderValuesSetter = (request, name, value) => request.Headers.Add(name, value);
 
     private static readonly Version Version = AssemblyName.Version;
     private static readonly ActivitySource WebRequestActivitySource = new ActivitySource(ActivitySourceName, Version.ToString());
 
+    private static readonly Meter WebRequestMeter = new Meter(InstrumentationName, Version.ToString());
+    private static readonly Histogram<double> HttpClientDuration;
+
     private static HttpClientInstrumentationOptions options;
 
     private static bool emitOldAttributes;
@@ -87,6 +92,7 @@ static HttpWebRequestActivitySource()
             PerformInjection();
 
             Options = new HttpClientInstrumentationOptions();
+            HttpClientDuration = WebRequestMeter.CreateHistogram<double>("http.client.duration", "ms", "Measures the duration of outbound HTTP requests.");
         }
         catch (Exception ex)
         {
@@ -396,6 +402,47 @@ private static void ProcessResult(IAsyncResult asyncResult, AsyncCallback asyncC
         }
 
         activity.Stop();
+
+        TagList tags = default;
+
+        // see the spec https://github.com/open-telemetry/opentelemetry-specification/blob/v1.20.0/specification/trace/semantic_conventions/http.md
+        if (emitOldAttributes)
+        {
+            foreach (var tag in activity.TagObjects)
+            {
+                switch (tag.Key)
+                {
+                    case SemanticConventions.AttributeHttpMethod:
+                    case SemanticConventions.AttributeHttpScheme:
+                    case SemanticConventions.AttributeHttpFlavor:
+                    case SemanticConventions.AttributeNetPeerName:
+                    case SemanticConventions.AttributeNetPeerPort:
+                    case SemanticConventions.AttributeHttpStatusCode:
+                        tags.Add(new KeyValuePair<string, object>(tag.Key, tag.Value));
+                        break;
+                }
+            }
+        }
+
+        // see the spec https://github.com/open-telemetry/semantic-conventions/blob/v1.21.0/docs/http/http-spans.md
+        if (emitNewAttributes)
+        {
+            foreach (var tag in activity.TagObjects)
+            {
+                switch (tag.Key)
+                {
+                    case SemanticConventions.AttributeHttpRequestMethod:
+                    case SemanticConventions.AttributeNetworkProtocolVersion:
+                    case SemanticConventions.AttributeServerAddress:
+                    case SemanticConventions.AttributeServerPort:
+                    case SemanticConventions.AttributeHttpResponseStatusCode:
+                        tags.Add(new KeyValuePair<string, object>(tag.Key, tag.Value));
+                        break;
+                }
+            }
+        }
+
+        HttpClientDuration.Record(activity.Duration.TotalMilliseconds, tags);
     }
 
     private static void PrepareReflectionObjects()

src/OpenTelemetry.Instrumentation.Http/MeterProviderBuilderExtensions.cs

@@ -34,12 +34,26 @@ public static class MeterProviderBuilderExtensions
     /// <returns>The instance of <see cref="MeterProviderBuilder"/> to chain the calls.</returns>
     public static MeterProviderBuilder AddHttpClientInstrumentation(
         this MeterProviderBuilder builder)
+    {
+        return AddHttpClientInstrumentation(builder, name: null);
+    }
+
+    /// <summary>
+    /// Enables HttpClient instrumentation.
+    /// </summary>
+    /// <param name="builder"><see cref="MeterProviderBuilder"/> being configured.</param>
+    /// <param name="name">Name which is used when retrieving options.</param>
+    /// <returns>The instance of <see cref="MeterProviderBuilder"/> to chain the calls.</returns>
+    public static MeterProviderBuilder AddHttpClientInstrumentation(
+        this MeterProviderBuilder builder, string name)
     {
         Guard.ThrowIfNull(builder);
 
         // Note: Warm-up the status code mapping.
         _ = TelemetryHelper.BoxedStatusCodes;
 
+        name ??= Options.DefaultName;
+
         builder.ConfigureServices(services =>
         {
             services.RegisterOptionsFactory(configuration => new HttpClientMetricInstrumentationOptions(configuration));
@@ -54,7 +68,22 @@ public static MeterProviderBuilder AddHttpClientInstrumentation(
         //   RecordException - probably doesn't make sense for metric instrumentation
 
         builder.AddMeter(HttpClientMetrics.InstrumentationName);
-        return builder.AddInstrumentation(sp => new HttpClientMetrics(
+        builder.AddInstrumentation(sp => new HttpClientMetrics(
             sp.GetRequiredService<IOptionsMonitor<HttpClientMetricInstrumentationOptions>>().CurrentValue));
+
+#if NETFRAMEWORK
+        builder.AddMeter(HttpWebRequestActivitySource.InstrumentationName);
+        builder.ConfigureServices(s =>
+        {
+            s.ConfigureOpenTelemetryMeterProvider((sp, _) =>
+            {
+                var options = sp.GetRequiredService<IOptionsMonitor<HttpClientInstrumentationOptions>>().Get(name);
+
+                HttpWebRequestActivitySource.Options = options;
+            });
+        });
+#endif
+
+        return builder;
     }
 }

src/OpenTelemetry.Instrumentation.Http/README.md

@@ -68,7 +68,7 @@ public class Program
 #### Metrics
 
 > **Note**
-> Metrics are not available for .NET Framework.
+> Metrics are only available for .NET Framework when tracing is enabled.
 
 The following example demonstrates adding `HttpClient` instrumentation with the
 extension method `.AddHttpClientInstrumentation()` on `MeterProviderBuilder` to

test/OpenTelemetry.Instrumentation.Http.Tests/HttpClientTests.cs

@@ -159,9 +159,6 @@ public async Task HttpOutCallsAreCollectedSuccessfullyAsync(HttpTestData.HttpOut
             Assert.True(enrichWithExceptionCalled);
         }
 
-#if NETFRAMEWORK
-        Assert.Empty(requestMetrics);
-#else
         Assert.Single(requestMetrics);
 
         var metric = requestMetrics[0];
@@ -193,7 +190,11 @@ public async Task HttpOutCallsAreCollectedSuccessfullyAsync(HttpTestData.HttpOut
         var method = new KeyValuePair<string, object>(SemanticConventions.AttributeHttpMethod, tc.Method);
         var scheme = new KeyValuePair<string, object>(SemanticConventions.AttributeHttpScheme, "http");
         var statusCode = new KeyValuePair<string, object>(SemanticConventions.AttributeHttpStatusCode, tc.ResponseCode == 0 ? 200 : tc.ResponseCode);
+#if NETFRAMEWORK
+        var flavor = new KeyValuePair<string, object>(SemanticConventions.AttributeHttpFlavor, "1.1");
+#else
         var flavor = new KeyValuePair<string, object>(SemanticConventions.AttributeHttpFlavor, "2.0");
+#endif
         var hostName = new KeyValuePair<string, object>(SemanticConventions.AttributeNetPeerName, tc.ResponseExpected ? host : "sdlfaldfjalkdfjlkajdflkajlsdjf");
         var portNumber = new KeyValuePair<string, object>(SemanticConventions.AttributeNetPeerPort, port);
         Assert.Contains(hostName, attributes);
@@ -211,7 +212,6 @@ public async Task HttpOutCallsAreCollectedSuccessfullyAsync(HttpTestData.HttpOut
             Assert.DoesNotContain(statusCode, attributes);
             Assert.Equal(5, attributes.Length);
         }
-#endif
     }
 
     [Fact]