3316: Filter out 400 and 404 response codes from failed requests tele…

…metry (#3399)

src/NuGetGallery/App_Start/OwinStartup.cs

@@ -20,6 +20,7 @@
 using NuGetGallery.Authentication.Providers;
 using NuGetGallery.Authentication.Providers.Cookie;
 using NuGetGallery.Configuration;
+using NuGetGallery.Helpers;
 using NuGetGallery.Infrastructure;
 using Owin;
 
@@ -58,16 +59,19 @@ public static void Configuration(IAppBuilder app)
             {
                 TelemetryConfiguration.Active.InstrumentationKey = instrumentationKey;
 
+                var telemetryProcessorChainBuilder = TelemetryConfiguration.Active.TelemetryProcessorChainBuilder;
+                telemetryProcessorChainBuilder.Use(next => new TelemetryResponseCodeFilter(next));
+
                 // Note: sampling rate must be a factor 100/N where N is a whole number
                 // e.g.: 50 (= 100/2), 33.33 (= 100/3), 25 (= 100/4), ...
                 // https://azure.microsoft.com/en-us/documentation/articles/app-insights-sampling/
                 var instrumentationSamplingPercentage = config.Current.AppInsightsSamplingPercentage;
                 if (instrumentationSamplingPercentage > 0 && instrumentationSamplingPercentage < 100)
                 {
-                    var telemetryProcessorChainBuilder = TelemetryConfiguration.Active.TelemetryProcessorChainBuilder;
                     telemetryProcessorChainBuilder.UseSampling(instrumentationSamplingPercentage);
-                    telemetryProcessorChainBuilder.Build();
                 }
+
+                telemetryProcessorChainBuilder.Build();
             }
 
             // Configure logging

src/NuGetGallery/Helpers/TelemetryResponseCodeFilter.cs

@@ -0,0 +1,32 @@
+using Microsoft.ApplicationInsights.Extensibility;
+using Microsoft.ApplicationInsights.Channel;
+using Microsoft.ApplicationInsights.DataContracts;
+
+namespace NuGetGallery.Helpers
+{
+    public class TelemetryResponseCodeFilter : ITelemetryProcessor
+    {
+        public TelemetryResponseCodeFilter(ITelemetryProcessor next)
+        {
+            Next = next;
+        }
+
+        private ITelemetryProcessor Next { get; set; }
+
+        public void Process(ITelemetry item)
+        {
+            var request = item as RequestTelemetry;
+            int responseCode;
+
+            if (request != null && int.TryParse(request.ResponseCode, out responseCode))
+            {
+                if (responseCode == 400 || responseCode == 404)
+                {
+                    request.Success = true;
+                }
+            }
+
+            this.Next.Process(item);
+        }
+    }
+}

src/NuGetGallery/NuGetGallery.csproj

@@ -747,6 +747,7 @@
     <Compile Include="Controllers\ErrorsController.cs" />
     <Compile Include="Controllers\PagesController.cs" />
     <Compile Include="GlobalSuppressions.cs" />
+    <Compile Include="Helpers\TelemetryResponseCodeFilter.cs" />
     <Compile Include="Infrastructure\Authentication\CredentialBuilder.cs" />
     <Compile Include="Infrastructure\Authentication\CredentialValidator.cs" />
     <Compile Include="Infrastructure\Authentication\ICredentialBuilder.cs" />