React to runtime EventSource changes

src/TelemetryConsumption/Http/HttpEventListenerService.cs

@@ -15,7 +15,11 @@ internal sealed class HttpEventListenerService : EventListenerService<HttpEventL
 {
     protected override string EventSourceName => "System.Net.Http";
 
+#if NET8_0_OR_GREATER
+    protected override int NumberOfMetrics => 11;
+#else
     protected override int NumberOfMetrics => 9;
+#endif
 
     public HttpEventListenerService(ILogger<HttpEventListenerService> logger, IEnumerable<IHttpTelemetryConsumer> telemetryConsumers, IEnumerable<IMetricsConsumer<HttpMetrics>> metricsConsumers)
         : base(logger, telemetryConsumers, metricsConsumers)
@@ -48,39 +52,83 @@ protected override void OnEvent(IHttpTelemetryConsumer[] consumers, EventWritten
                 break;
 
             case 2:
-                Debug.Assert(eventData.EventName == "RequestStop" /* && payload.Count == 0 */);
+                Debug.Assert(eventData.EventName == "RequestStop" && payload.Count == (eventData.Version == 0 ? 0 : 1));
                 {
+#if NET8_0_OR_GREATER
+                    var statusCode = (int)payload[0];
+                    foreach (var consumer in consumers)
+                    {
+                        consumer.OnRequestStop(eventData.TimeStamp, statusCode);
+                    }
+#else
                     foreach (var consumer in consumers)
                     {
                         consumer.OnRequestStop(eventData.TimeStamp);
                     }
+#endif
                 }
                 break;
 
             case 3:
-                Debug.Assert(eventData.EventName == "RequestFailed" /* && payload.Count == 0 */);
+                Debug.Assert(eventData.EventName == "RequestFailed" && payload.Count == (eventData.Version == 0 ? 0 : 1));
                 {
+#if NET8_0_OR_GREATER
+                    var exceptionMessage = (string)payload[0];
+                    foreach (var consumer in consumers)
+                    {
+                        consumer.OnRequestFailed(eventData.TimeStamp, exceptionMessage);
+                    }
+#else
                     foreach (var consumer in consumers)
                     {
                         consumer.OnRequestFailed(eventData.TimeStamp);
                     }
+#endif
                 }
                 break;
 
             case 4:
-                Debug.Assert(eventData.EventName == "ConnectionEstablished" && payload.Count == 2);
+                Debug.Assert(eventData.EventName == "ConnectionEstablished" && payload.Count == (eventData.Version == 0 ? 2 : 7));
                 {
                     var versionMajor = (int)(byte)payload[0];
                     var versionMinor = (int)(byte)payload[1];
+#if NET8_0_OR_GREATER
+                    var connectionId = (long)payload[2];
+                    var scheme = (string)payload[3];
+                    var host = (string)payload[4];
+                    var port = (int)payload[5];
+                    var remoteAddress = (string?)payload[6];
+                    foreach (var consumer in consumers)
+                    {
+                        consumer.OnConnectionEstablished(eventData.TimeStamp, versionMajor, versionMinor, connectionId, scheme, host, port, remoteAddress);
+                    }
+#else
                     foreach (var consumer in consumers)
                     {
                         consumer.OnConnectionEstablished(eventData.TimeStamp, versionMajor, versionMinor);
                     }
+#endif
                 }
                 break;
 
             case 5:
-                Debug.Assert(eventData.EventName == "ConnectionClosed" && payload.Count == 2);
+                Debug.Assert(eventData.EventName == "ConnectionClosed" && payload.Count == (eventData.Version == 0 ? 2 : 3));
+                {
+                    var versionMajor = (int)(byte)payload[0];
+                    var versionMinor = (int)(byte)payload[1];
+#if NET8_0_OR_GREATER
+                    var connectionId = (long)payload[2];
+                    foreach (var consumer in consumers)
+                    {
+                        consumer.OnConnectionClosed(eventData.TimeStamp, versionMajor, versionMinor, connectionId);
+                    }
+#else
+                    foreach (var consumer in consumers)
+                    {
+                        consumer.OnConnectionClosed(eventData.TimeStamp, versionMajor, versionMinor);
+                    }
+#endif
+                }
                 break;
 
             case 6:
@@ -97,12 +145,20 @@ protected override void OnEvent(IHttpTelemetryConsumer[] consumers, EventWritten
                 break;
 
             case 7:
-                Debug.Assert(eventData.EventName == "RequestHeadersStart" && payload.Count == 0);
+                Debug.Assert(eventData.EventName == "RequestHeadersStart" && payload.Count == (eventData.Version == 0 ? 0 : 1));
                 {
+#if NET8_0_OR_GREATER
+                    var connectionId = (long)payload[0];
+                    foreach (var consumer in consumers)
+                    {
+                        consumer.OnRequestHeadersStart(eventData.TimeStamp, connectionId);
+                    }
+#else
                     foreach (var consumer in consumers)
                     {
                         consumer.OnRequestHeadersStart(eventData.TimeStamp);
                     }
+#endif
                 }
                 break;
 
@@ -148,14 +204,61 @@ protected override void OnEvent(IHttpTelemetryConsumer[] consumers, EventWritten
                 break;
 
             case 12:
-                Debug.Assert(eventData.EventName == "ResponseHeadersStop" /* && payload.Count == 0 */);
+                Debug.Assert(eventData.EventName == "ResponseHeadersStop" && payload.Count == (eventData.Version == 0 ? 0 : 1));
                 {
+#if NET8_0_OR_GREATER
+                    var statusCode = (int)payload[0];
+                    foreach (var consumer in consumers)
+                    {
+                        consumer.OnResponseHeadersStop(eventData.TimeStamp, statusCode);
+                    }
+#else
                     foreach (var consumer in consumers)
                     {
                         consumer.OnResponseHeadersStop(eventData.TimeStamp);
                     }
+#endif
+                }
+                break;
+
+            case 13:
+                Debug.Assert(eventData.EventName == "ResponseContentStart" && payload.Count == 0);
+                {
+                    foreach (var consumer in consumers)
+                    {
+                        consumer.OnResponseContentStart(eventData.TimeStamp);
+                    }
+                }
+                break;
+
+            case 14:
+                Debug.Assert(eventData.EventName == "ResponseContentStop" && payload.Count == 0);
+                {
+                    foreach (var consumer in consumers)
+                    {
+                        consumer.OnResponseContentStop(eventData.TimeStamp);
+                    }
                 }
                 break;
+
+            case 15:
+                Debug.Assert(eventData.EventName == "RequestFailedDetailed" && payload.Count == 1);
+                // This event is more expensive to collect and requires an opt-in keyword.
+                Debug.Fail("We shouldn't be seeing this event as the base EventListenerService always uses EventKeywords.None.");
+                break;
+
+            case 16:
+                Debug.Assert(eventData.EventName == "Redirect" && payload.Count == 1);
+#if NET8_0_OR_GREATER
+                {
+                    var redirectUri = (string)payload[0];
+                    foreach (var consumer in consumers)
+                    {
+                        consumer.OnRedirect(eventData.TimeStamp, redirectUri);
+                    }
+                }
+#endif
+                break;
         }
     }
 
@@ -199,6 +302,16 @@ protected override bool TrySaveMetric(HttpMetrics metrics, string name, double v
                 metrics.Http20RequestsQueueDuration = TimeSpan.FromMilliseconds(value);
                 break;
 
+#if NET8_0_OR_GREATER
+            case "http30-connections-current-total":
+                metrics.CurrentHttp30Connections = (long)value;
+                break;
+
+            case "http30-requests-queue-duration":
+                metrics.Http30RequestsQueueDuration = TimeSpan.FromMilliseconds(value);
+                break;
+#endif
+
             default:
                 return false;
         }

src/TelemetryConsumption/Http/HttpMetrics.cs

@@ -61,4 +61,16 @@ public sealed class HttpMetrics
     /// Average time spent on queue for HTTP 2.0 requests that hit the MAX_CONCURRENT_STREAMS limit on the connection in the last metrics interval.
     /// </summary>
     public TimeSpan Http20RequestsQueueDuration { get; internal set; }
+
+#if NET8_0_OR_GREATER
+    /// <summary>
+    /// Number of currently open HTTP 3.0 connections.
+    /// </summary>
+    public long CurrentHttp30Connections { get; internal set; }
+
+    /// <summary>
+    /// Average time spent on queue for HTTP 3.0 requests in the last metrics interval.
+    /// </summary>
+    public TimeSpan Http30RequestsQueueDuration { get; internal set; }
+#endif
 }

src/TelemetryConsumption/Http/IHttpTelemetryConsumer.cs

@@ -44,6 +44,14 @@ void OnRequestFailed(DateTime timestamp) { }
     /// <param name="versionMinor">Minor component of the connection's HTTP version.</param>
     void OnConnectionEstablished(DateTime timestamp, int versionMajor, int versionMinor) { }
 
+    /// <summary>
+    /// Called when a new HTTP connection is closed.
+    /// </summary>
+    /// <param name="timestamp">Timestamp when the event was fired.</param>
+    /// <param name="versionMajor">Major component of the connection's HTTP version.</param>
+    /// <param name="versionMinor">Minor component of the connection's HTTP version.</param>
+    void OnConnectionClosed(DateTime timestamp, int versionMajor, int versionMinor) { }
+
     /// <summary>
     /// Called when a request that hit the MaxConnectionsPerServer or MAX_CONCURRENT_STREAMS limit leaves the queue.
     /// </summary>
@@ -89,4 +97,85 @@ void OnResponseHeadersStart(DateTime timestamp) { }
     /// </summary>
     /// <param name="timestamp">Timestamp when the event was fired.</param>
     void OnResponseHeadersStop(DateTime timestamp) { }
+
+    /// <summary>
+    /// Called when <see cref="HttpClient"/> starts buffering the response content.
+    /// This event WILL NOT be called for requests made by YARP, as they are not buffered.
+    /// </summary>
+    /// <param name="timestamp">Timestamp when the event was fired.</param>
+    void OnResponseContentStart(DateTime timestamp) { }
+
+    /// <summary>
+    /// Called when <see cref="HttpClient"/> stops buffering the response content.
+    /// This event WILL NOT be called for requests made by YARP, as they are not buffered.
+    /// </summary>
+    /// <param name="timestamp">Timestamp when the event was fired.</param>
+    void OnResponseContentStop(DateTime timestamp) { }
+
+    // Some events were augmented in .NET 8 with more parameters.
+    // For backwards compatibility, they are implemented as DIMs that forward to older methods with fewer parameters.
+#if NET8_0_OR_GREATER
+    /// <summary>
+    /// Called after an HTTP request.
+    /// </summary>
+    /// <param name="timestamp">Timestamp when the event was fired.</param>
+    /// <param name="statusCode">The status code returned by the server. -1 if no response was received.</param>
+    void OnRequestStop(DateTime timestamp, int statusCode) =>
+        OnRequestStop(timestamp);
+
+    /// <summary>
+    /// Called before <see cref="OnRequestStop(DateTime)"/> if the request failed.
+    /// </summary>
+    /// <param name="timestamp">Timestamp when the event was fired.</param>
+    /// <param name="exceptionMessage">A message that describes the exception associated with this request failure.</param>
+    void OnRequestFailed(DateTime timestamp, string exceptionMessage) =>
+        OnRequestFailed(timestamp);
+
+    /// <summary>
+    /// Called when a new HTTP connection is established.
+    /// </summary>
+    /// <param name="timestamp">Timestamp when the event was fired.</param>
+    /// <param name="versionMajor">Major component of the connection's HTTP version.</param>
+    /// <param name="versionMinor">Minor component of the connection's HTTP version.</param>
+    /// <param name="connectionId">ID of the connection that was established, unique for this process.</param>
+    /// <param name="scheme">Scheme the connection was established with.</param>
+    /// <param name="host">Host the connection was established to.</param>
+    /// <param name="port">Port the connection was established to.</param>
+    /// <param name="remoteAddress">The remote address this connection was established to, if available.</param>
+    void OnConnectionEstablished(DateTime timestamp, int versionMajor, int versionMinor, long connectionId, string scheme, string host, int port, string? remoteAddress) =>
+        OnConnectionEstablished(timestamp, versionMajor, versionMinor);
+
+    /// <summary>
+    /// Called when a new HTTP connection is closed.
+    /// </summary>
+    /// <param name="timestamp">Timestamp when the event was fired.</param>
+    /// <param name="versionMajor">Major component of the connection's HTTP version.</param>
+    /// <param name="versionMinor">Minor component of the connection's HTTP version.</param>
+    /// <param name="connectionId">ID of the connection that was closed.</param>
+    void OnConnectionClosed(DateTime timestamp, int versionMajor, int versionMinor, long connectionId) =>
+        OnConnectionClosed(timestamp, versionMajor, versionMinor);
+
+    /// <summary>
+    /// Called before sending the request headers.
+    /// </summary>
+    /// <param name="timestamp">Timestamp when the event was fired.</param>
+    /// <param name="connectionId">ID of the connection we are sending this request on.</param>
+    void OnRequestHeadersStart(DateTime timestamp, long connectionId) =>
+        OnRequestHeadersStart(timestamp);
+
+    /// <summary>
+    /// Called after reading all response headers.
+    /// </summary>
+    /// <param name="timestamp">Timestamp when the event was fired.</param>
+    /// <param name="statusCode">The status code returned by the server.</param>
+    void OnResponseHeadersStop(DateTime timestamp, int statusCode) =>
+        OnResponseHeadersStop(timestamp);
+
+    /// <summary>
+    /// Called before a request is redirected if <see cref="SocketsHttpHandler.AllowAutoRedirect"/> is enabled.
+    /// </summary>
+    /// <param name="timestamp">Timestamp when the event was fired.</param>
+    /// <param name="redirectUri">The uri the request is being redirected to.</param>
+    void OnRedirect(DateTime timestamp, string redirectUri) { }
+#endif
 }

src/TelemetryConsumption/Sockets/SocketsEventListenerService.cs

@@ -14,7 +14,11 @@ internal sealed class SocketsEventListenerService : EventListenerService<Sockets
 {
     protected override string EventSourceName => "System.Net.Sockets";
 
+#if NET8_0_OR_GREATER
+    protected override int NumberOfMetrics => 7;
+#else
     protected override int NumberOfMetrics => 6;
+#endif
 
     public SocketsEventListenerService(ILogger<SocketsEventListenerService> logger, IEnumerable<ISocketsTelemetryConsumer> telemetryConsumers, IEnumerable<IMetricsConsumer<SocketsMetrics>> metricsConsumers)
         : base(logger, telemetryConsumers, metricsConsumers)
@@ -94,6 +98,12 @@ protected override bool TrySaveMetric(SocketsMetrics metrics, string name, doubl
                 metrics.DatagramsSent = longValue;
                 break;
 
+#if NET8_0_OR_GREATER
+            case "current-outgoing-connect-attempts":
+                metrics.CurrentOutgoingConnectAttempts = longValue;
+                break;
+#endif
+
             default:
                 return false;
         }

src/TelemetryConsumption/Sockets/SocketsMetrics.cs

@@ -46,4 +46,11 @@ public sealed class SocketsMetrics
     /// Number of datagrams sent since telemetry was enabled.
     /// </summary>
     public long DatagramsSent { get; internal set; }
+
+#if NET8_0_OR_GREATER
+    /// <summary>
+    /// Number of outgoing (Connect) Socket connection attempts that are currently in progress.
+    /// </summary>
+    public long CurrentOutgoingConnectAttempts { get; internal set; }
+#endif
 }