Addressed feedback

Author: kichalla

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

@@ -43,7 +43,7 @@ public Context CreateContext(IFeatureCollection contextFeatures)
                 _diagnosticSource.Write("Microsoft.AspNetCore.Hosting.BeginRequest", new { httpContext = httpContext, timestamp = startTimestamp });
             }
 
-            HostingEventSource.Log.RequestStart(httpContext);
+            HostingEventSource.Log.RequestStart(httpContext.Request.Method, httpContext.Request.Path);
 
             return new Context
             {
@@ -69,7 +69,7 @@ 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();
             }
             else
             {
@@ -83,7 +83,8 @@ 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.UnhandledException();
+                HostingEventSource.Log.RequestStop();
             }
 
             context.Scope?.Dispose();

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

@@ -1,11 +1,8 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using System;
-using System.Linq;
 using System.Diagnostics.Tracing;
 using Microsoft.AspNetCore.Http;
-using Microsoft.Net.Http.Headers;
 
 namespace Microsoft.AspNetCore.Hosting.Internal
 {
@@ -16,10 +13,12 @@ public sealed class HostingEventSource : EventSource
 
         private HostingEventSource() { }
 
-        // The 'Start' and 'Stop' suffixes on the following event names have special meaning in EventSource. They
-        // enable creating 'activities'.
-        // For more information, take a look at the following blog post:
-        // https://blogs.msdn.microsoft.com/vancem/2015/09/14/exploring-eventsource-activity-correlation-and-causation-features/
+        // NOTE
+        // - The 'Start' and 'Stop' suffixes on the following event names have special meaning in EventSource. They
+        //   enable creating 'activities'.
+        //   For more information, take a look at the following blog post:
+        //   https://blogs.msdn.microsoft.com/vancem/2015/09/14/exploring-eventsource-activity-correlation-and-causation-features/
+        // - A stop event's event id must be next one after its start event.
 
         [Event(1, Level = EventLevel.Informational)]
         public void HostStart()
@@ -33,69 +32,22 @@ public void HostStop()
             WriteEvent(2);
         }
 
-        [NonEvent]
-        public void RequestStart(HttpContext context)
-        {
-            if (IsEnabled())
-            {
-                RequestStart(
-                    context.TraceIdentifier,
-                    context.Request.Protocol,
-                    context.Request.Method,
-                    context.Request.ContentType ?? string.Empty,
-                    context.Request.ContentLength.HasValue ? context.Request.ContentLength.Value.ToString() : string.Empty,
-                    context.Request.Scheme,
-                    context.Request.Host.Value,
-                    context.Request.PathBase,
-                    context.Request.Path,
-                    context.Request.QueryString.Value);
-            }
-        }
-
-        [NonEvent]
-        public void RequestStop(HttpContext context, Exception exception = null)
+        [Event(3, Level = EventLevel.Informational)]
+        public void RequestStart(string method, string path)
         {
-            if (IsEnabled())
-            {
-                RequestStop(
-                    context.Response.StatusCode,
-                    context.Response.ContentType ?? string.Empty,
-                    context.TraceIdentifier,
-                    exception == null ? string.Empty : exception.ToString());
-            }
+            WriteEvent(3, method, path);
         }
 
-        [Event(3, Level = EventLevel.Informational)]
-        private void RequestStart(
-            string requestTraceIdentifier,
-            string protocol,
-            string method,
-            string contentType,
-            string contentLength,
-            string scheme,
-            string host,
-            string pathBase,
-            string path,
-            string queryString)
+        [Event(4, Level = EventLevel.Informational)]
+        public void RequestStop()
         {
-            WriteEvent(
-                3,
-                requestTraceIdentifier,
-                protocol,
-                method,
-                contentType,
-                contentLength,
-                scheme,
-                host,
-                pathBase,
-                path,
-                queryString);
+            WriteEvent(4);
         }
 
-        [Event(4, Level = EventLevel.Informational)]
-        private void RequestStop(int statusCode, string contentType, string requestTraceIdentifier, string exception)
+        [Event(5, Level = EventLevel.Error)]
+        public void UnhandledException()
         {
-            WriteEvent(4, statusCode, contentType, requestTraceIdentifier, exception);
+            WriteEvent(5);
         }
     }
 }