Added event counters

Author: kichalla

src/Microsoft.AspNetCore.Hosting/Internal/HostingApplication.cs

@@ -34,7 +34,9 @@ public Context CreateContext(IFeatureCollection contextFeatures)
         {
             var httpContext = _httpContextFactory.Create(contextFeatures);
             var diagnoticsEnabled = _diagnosticSource.IsEnabled("Microsoft.AspNetCore.Hosting.BeginRequest");
-            var startTimestamp = (diagnoticsEnabled || _logger.IsEnabled(LogLevel.Information)) ? Stopwatch.GetTimestamp() : 0;
+            var startTimestamp = (diagnoticsEnabled
+                || _logger.IsEnabled(LogLevel.Information)
+                || HostingEventSource.Log.IsEnabled()) ? Stopwatch.GetTimestamp() : 0;
 
             var scope = _logger.RequestScope(httpContext);
             _logger.RequestStarting(httpContext);
@@ -68,8 +70,7 @@ public void DisposeContext(Context context, Exception exception)
                 {
                     _diagnosticSource.Write("Microsoft.AspNetCore.Hosting.EndRequest", new { httpContext = httpContext, timestamp = currentTimestamp });
                 }
-
-                HostingEventSource.Log.RequestStop(httpContext);
+                HostingEventSource.Log.RequestStop(httpContext, context.StartTimestamp, currentTimestamp);
             }
             else
             {
@@ -82,8 +83,7 @@ public void DisposeContext(Context context, Exception exception)
                 {
                     _diagnosticSource.Write("Microsoft.AspNetCore.Hosting.UnhandledException", new { httpContext = httpContext, timestamp = currentTimestamp, exception = exception });
                 }
-
-                HostingEventSource.Log.RequestStop(httpContext, exception);
+                HostingEventSource.Log.RequestStop(httpContext, context.StartTimestamp, currentTimestamp, exception);
             }
 
             context.Scope?.Dispose();

src/Microsoft.AspNetCore.Hosting/Internal/HostingEventSource.cs

@@ -12,7 +12,22 @@ public sealed class HostingEventSource : EventSource
     {
         public static readonly HostingEventSource Log = new HostingEventSource();
 
-        private HostingEventSource() { }
+#if NETSTANDARD1_5
+        private EventCounter _requestCounter = null;
+        private EventCounter _successfulRequestCounter = null;
+        private EventCounter _failedRequestCounter = null;
+        private EventCounter _requestExecutionTimeCounter = null;
+#endif
+
+        private HostingEventSource()
+        {
+#if NETSTANDARD1_5
+            _requestCounter = new EventCounter("Request", this);
+            _successfulRequestCounter = new EventCounter("SuccessfulRequest", this);
+            _failedRequestCounter = new EventCounter("FailedRequest", this);
+            _requestExecutionTimeCounter = new EventCounter("RequestExecutionTime", this);
+#endif
+        }
 
         [Event(1, Level = EventLevel.Informational)]
         public void HostStart()
@@ -29,6 +44,9 @@ public void HostStop()
         [NonEvent]
         public void RequestStart(HttpContext context)
         {
+#if NETSTANDARD1_5
+            _requestCounter.WriteMetric(1);
+#endif
             if (IsEnabled())
             {
                 RequestStart(
@@ -46,8 +64,23 @@ public void RequestStart(HttpContext context)
         }
 
         [NonEvent]
-        public void RequestStop(HttpContext context, Exception exception = null)
+        public void RequestStop(HttpContext context, long startTimestamp, long endTimestamp, Exception exception = null)
         {
+#if NETSTANDARD1_5
+            if (exception == null)
+            {
+                _successfulRequestCounter.WriteMetric(1);
+            }
+            else
+            {
+                _failedRequestCounter.WriteMetric(1);
+            }
+
+            if (endTimestamp != 0)
+            {
+                _requestExecutionTimeCounter.WriteMetric(endTimestamp - startTimestamp);
+            }
+#endif
             if (IsEnabled())
             {
                 RequestStop(

src/Microsoft.AspNetCore.Hosting/project.json

@@ -77,6 +77,7 @@
     "netstandard1.5": {
       "dependencies": {
         "System.Diagnostics.StackTrace": "4.3.0-*",
+        "System.Diagnostics.Tracing": "4.3.0-*",
         "System.Runtime.Loader": "4.3.0-*"
       }
     }