Added some kestrel event counters (#21649)

* Added some kestrel event counters
- Connection queue length - This is the amount of connections accepted and queued in the thread pool.
- Connection count - The number of connections
- Total connections - The total number of connections ever connected.
- Connection Rate - Connections per second

* Added TLS counters
- Current TLS handshakes
- Total TLS handshakes
- Failed TLS handshakes
- TLS handshake per second

* Added HTTP/2 queue length counter

* Improve the event information
- Add TLS version to handshake events
- Add HTTP version to request queue events
- Renamed HTTP/2 request queue length to http request queue


Contributes to #4769

Author: davidfowl

src/Servers/Kestrel/Core/src/Internal/ConnectionDispatcher.cs

@@ -61,6 +61,7 @@ async Task AcceptConnectionsAsync()
                         _transportConnectionManager.AddConnection(id, kestrelConnection);
 
                         Log.ConnectionAccepted(connection.ConnectionId);
+                        KestrelEventSource.Log.ConnectionQueuedStart(connection);
 
                         ThreadPool.UnsafeQueueUserWorkItem(kestrelConnection, preferLocal: false);
                     }

src/Servers/Kestrel/Core/src/Internal/Http/Http1Connection.cs

@@ -76,6 +76,13 @@ public Http1Connection(HttpConnectionContext context)
 
         protected override void OnRequestProcessingEnded()
         {
+            if (IsUpgraded)
+            {
+                KestrelEventSource.Log.RequestUpgradedStop(this);
+
+                ServiceContext.ConnectionManager.UpgradedConnectionCount.ReleaseOne();
+            }
+
             TimeoutControl.StartDrainTimeout(MinResponseDataRate, ServerOptions.Limits.MaxResponseBufferSize);
 
             // Prevent RequestAborted from firing. Free up unneeded feature references.

src/Servers/Kestrel/Core/src/Internal/Http/HttpProtocol.FeatureCollection.cs

@@ -293,6 +293,8 @@ async Task<Stream> IHttpUpgradeFeature.UpgradeAsync()
 
             IsUpgraded = true;
 
+            KestrelEventSource.Log.RequestUpgradedStart(this);
+
             ConnectionFeatures.Get<IDecrementConcurrentConnectionCountFeature>()?.ReleaseConnection();
 
             StatusCode = StatusCodes.Status101SwitchingProtocols;

src/Servers/Kestrel/Core/src/Internal/Http/HttpProtocol.cs

@@ -136,6 +136,7 @@ public string TraceIdentifier
         public int LocalPort { get; set; }
         public string Scheme { get; set; }
         public HttpMethod Method { get; set; }
+        public string MethodText => ((IHttpRequestFeature)this).Method;
         public string PathBase { get; set; }
 
         public string Path { get; set; }

src/Servers/Kestrel/Core/src/Internal/Http2/Http2Connection.cs

@@ -1002,6 +1002,7 @@ private void StartStream()
                 throw;
             }
 
+            KestrelEventSource.Log.RequestQueuedStart(_currentHeadersStream, AspNetCore.Http.HttpProtocol.Http2);
             // Must not allow app code to block the connection handling loop.
             ThreadPool.UnsafeQueueUserWorkItem(_currentHeadersStream, preferLocal: false);
         }

src/Servers/Kestrel/Core/src/Internal/Http2/Http2StreamOfT.cs

@@ -4,6 +4,7 @@
 
 using Microsoft.AspNetCore.Hosting.Server;
 using Microsoft.AspNetCore.Hosting.Server.Abstractions;
+using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2
 {
@@ -19,6 +20,7 @@ public Http2Stream(IHttpApplication<TContext> application, Http2StreamContext co
 
         public override void Execute()
         {
+            KestrelEventSource.Log.RequestQueuedStop(this, AspNetCore.Http.HttpProtocol.Http2);
             // REVIEW: Should we store this in a field for easy debugging?
             _ = ProcessRequestsAsync(_application);
         }

src/Servers/Kestrel/Core/src/Internal/Http3/Http3Connection.cs

@@ -243,6 +243,7 @@ internal async Task InnerProcessRequestsAsync<TContext>(IHttpApplication<TContex
                         {
                             _streams[streamId] = http3Stream;
                         }
+                        KestrelEventSource.Log.RequestQueuedStart(stream, AspNetCore.Http.HttpProtocol.Http3);
                         ThreadPool.UnsafeQueueUserWorkItem(stream, preferLocal: false);
                     }
                 }

src/Servers/Kestrel/Core/src/Internal/Http3/Http3StreamOfT.cs

@@ -3,6 +3,7 @@
 
 using Microsoft.AspNetCore.Hosting.Server;
 using Microsoft.AspNetCore.Hosting.Server.Abstractions;
+using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http3
 {
@@ -17,6 +18,8 @@ public Http3Stream(IHttpApplication<TContext> application, Http3Connection conne
 
         public override void Execute()
         {
+            KestrelEventSource.Log.RequestQueuedStop(this, AspNetCore.Http.HttpProtocol.Http3);
+
             if (_requestHeaderParsingState == Http3Stream.RequestHeaderParsingState.Ready)
             {
                 _ = ProcessRequestAsync(_application);

src/Servers/Kestrel/Core/src/Internal/HttpConnection.cs

@@ -107,13 +107,6 @@ public async Task ProcessRequestsAsync<TContext>(IHttpApplication<TContext> http
             {
                 Log.LogCritical(0, ex, $"Unexpected exception in {nameof(HttpConnection)}.{nameof(ProcessRequestsAsync)}.");
             }
-            finally
-            {
-                if (_http1Connection?.IsUpgraded == true)
-                {
-                    _context.ServiceContext.ConnectionManager.UpgradedConnectionCount.ReleaseOne();
-                }
-            }
         }
 
         // For testing only

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

@@ -40,6 +40,8 @@ internal async Task ExecuteAsync()
 
             try
             {
+                KestrelEventSource.Log.ConnectionQueuedStop(connectionContext);
+
                 Logger.ConnectionStart(connectionContext.ConnectionId);
                 KestrelEventSource.Log.ConnectionStart(connectionContext);