Detect issue with POST/PUT/PATCH requests correlation and report in event source actionable event

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Changelog
 
 ## Version 2.7.0-beta1
+- [Send UserActionable event about correlation issue with HTTP request with body when .NET 4.7.1 is not installed](https://github.com/Microsoft/ApplicationInsights-dotnet-server/pull/903)
 - [Added support to collect Perf Counters for .NET Core Apps if running inside Azure WebApps](https://github.com/Microsoft/ApplicationInsights-dotnet-server/issues/889)
 - [Opt-in legacy correlation headers (x-ms-request-id and x-ms-request-root-id) extraction and injection](https://github.com/Microsoft/ApplicationInsights-dotnet-server/issues/887)
 - [Fix: Correlation is not working for POST requests](https://github.com/Microsoft/ApplicationInsights-dotnet-server/pull/898) when .NET 4.7.1 runtime is installed.

Src/Web/Web.Shared.Net/Implementation/WebEventSource.cs

@@ -476,6 +476,17 @@ public void ActivityIsNull(string diagnosticsSourceEventName, string appDomainNa
             this.WriteEvent(48, diagnosticsSourceEventName, this.ApplicationName);
         }
 
+        [Event(49,
+            Keywords = Keywords.Diagnostics | Keywords.UserActionable,
+            Message = ".NET 4.7.1 is not installed, correlation for HTTP requests with body is not possible",
+            Level = EventLevel.Warning)]
+        public void CorrelationIssueIsDetectedForRequestWithBody(string appDomainName = "Incorrect")
+        {
+            this.WriteEvent(
+                49,
+                this.ApplicationName);
+        }
+
         [NonEvent]
         private string GetApplicationName()
         {

Src/Web/Web.Shared.Net/RequestTrackingTelemetryModule.cs

@@ -20,13 +20,14 @@
     public class RequestTrackingTelemetryModule : ITelemetryModule
     {
         private const string IntermediateRequestHttpContextKey = "IntermediateRequest";
-        private readonly IList<string> handlersToFilter = new List<string>();
+        // if HttpApplicaiton.OnRequestExecute is available, we don't attempt to detect any correlation issues
+        private static bool correlationIssuesDetectionComplete = typeof(HttpApplication).GetMethod("OnExecuteRequestStep") != null;
+
         private TelemetryClient telemetryClient;
         private TelemetryConfiguration telemetryConfiguration;
         private bool initializationErrorReported;
-        private bool correlationHeadersEnabled = true;
         private ChildRequestTrackingSuppressionModule childRequestTrackingSuppressionModule = null;
-        
+
         /// <summary>
         /// Gets or sets a value indicating whether child request suppression is enabled or disabled. 
         /// True by default.
@@ -53,34 +54,17 @@ public class RequestTrackingTelemetryModule : ITelemetryModule
         /// See also <see cref="ChildRequestTrackingSuppressionModule" />.
         /// </remarks>
         public int ChildRequestTrackingInternalDictionarySize { get; set; }
-        
+
         /// <summary>
         /// Gets the list of handler types for which requests telemetry will not be collected
         /// if request was successful.
         /// </summary>
-        public IList<string> Handlers
-        {
-            get
-            {
-                return this.handlersToFilter;
-            }
-        }
+        public IList<string> Handlers { get; } = new List<string>();
 
         /// <summary>
         /// Gets or sets a value indicating whether the component correlation headers would be set on http responses.
         /// </summary>
-        public bool SetComponentCorrelationHttpHeaders
-        {
-            get
-            {
-                return this.correlationHeadersEnabled;
-            }
-
-            set
-            {
-                this.correlationHeadersEnabled = value;
-            }
-        }
+        public bool SetComponentCorrelationHttpHeaders { get; set; } = true;
 
         /// <summary>
         /// Gets or sets the endpoint that is to be used to get the application insights resource's profile (appId etc.).
@@ -219,6 +203,12 @@ public void OnEndRequest(HttpContext context)
                 }
 
                 this.telemetryClient.TrackRequest(requestTelemetry);
+
+                if (!correlationIssuesDetectionComplete && context.Request.ContentLength > 0)
+                {
+                    WebEventSource.Log.CorrelationIssueIsDetectedForRequestWithBody();
+                    correlationIssuesDetectionComplete = true;
+                }
             }
             else
             {
@@ -394,7 +384,7 @@ private bool IsHandlerToFilter(IHttpHandler handler)
 
             return false;
         }
-        
+
         /// <summary>
         /// <see cref="System.Web.Handlers.TransferRequestHandler"/> can create a Child request to route extension-less requests to a controller.
         /// (ex: site/home -> site/HomeController.cs)