Azure Monitor Exporter - In debug mode write EventSource and Telemetry information to output window (Azure#16900)

* Log to output window

* debug directive correction.

* Rename eventsource

* Remove #if directive

* PR feedback - rename

* PR feedback

Author: rajkumar-rangaraj

sdk/monitor/Microsoft.OpenTelemetry.Exporter.AzureMonitor/CHANGELOG.md

@@ -3,6 +3,7 @@
 ## 1.0.0-beta.2 (Unreleased)
 
 * [Set Remote Dependency Telemetry semantics](https://github.com/Azure/azure-sdk-for-net/issues/17026)
+* [Supports sending EventSource and Telemetry output to the debug trace](https://github.com/Azure/azure-sdk-for-net/issues/16893)
 
 ## 1.0.0-beta.1 (2020-11-06)
 

sdk/monitor/Microsoft.OpenTelemetry.Exporter.AzureMonitor/src/ApplicationInsightsRestClient.cs

@@ -65,6 +65,7 @@ internal HttpMessage CreateTrackRequest(IEnumerable<TelemetryItem> body)
                 content.WriteNewLine();
             }
             request.Content = RequestContent.Create(content.ToBytes());
+            TelemetryDebugWriter.WriteTelemetry(content);
             return message;
         }
 
@@ -82,6 +83,7 @@ internal HttpMessage CreateTrackRequest(ReadOnlyMemory<byte> body)
             request.Headers.Add("Accept", "application/json");
             using var content = new NDJsonWriter();
             request.Content = RequestContent.Create(body);
+            TelemetryDebugWriter.WriteTelemetry(content);
             return message;
         }
     }

…/AzureMonitorTraceExporterEventSource.cs …r/src/AzureMonitorExporterEventSource.cssdk/monitor/Microsoft.OpenTelemetry.Exporter.AzureMonitor/src/AzureMonitorTraceExporterEventSource.cs renamed to sdk/monitor/Microsoft.OpenTelemetry.Exporter.AzureMonitor/src/AzureMonitorExporterEventSource.cs sdk/monitor/Microsoft.OpenTelemetry.Exporter.AzureMonitor/src/AzureMonitorTraceExporterEventSource.cs renamed to sdk/monitor/Microsoft.OpenTelemetry.Exporter.AzureMonitor/src/AzureMonitorExporterEventSource.cs

@@ -4,14 +4,17 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.Tracing;
+using Azure.Core.Shared;
 
 namespace Microsoft.OpenTelemetry.Exporter.AzureMonitor
 {
     [EventSource(Name = EventSourceName)]
-    internal sealed class AzureMonitorTraceExporterEventSource : EventSource
+    internal sealed class AzureMonitorExporterEventSource : EventSource
     {
-        private const string EventSourceName = "OpenTelemetry-TraceExporter-AzureMonitor";
-        public static AzureMonitorTraceExporterEventSource Log = new AzureMonitorTraceExporterEventSource();
+        private const string EventSourceName = "Microsoft-OpenTelemetry-Exporter-AzureMonitor";
+        public static AzureMonitorExporterEventSource Log = new AzureMonitorExporterEventSource();
+        public static AzureMonitorExporterEventListener Listener = new AzureMonitorExporterEventListener();
+
         public readonly IReadOnlyDictionary<string, EventLevel> EventLevelMap = new Dictionary<string, EventLevel>
         {
             [EventLevelSuffix.Critical] = EventLevel.Critical,
@@ -71,5 +74,38 @@ private static string GetMessage(object value)
         {
             return value is Exception exception ? exception.ToInvariantString() : value.ToString();
         }
+
+        public class AzureMonitorExporterEventListener : EventListener
+        {
+            private readonly List<EventSource> eventSources = new List<EventSource>();
+
+            public override void Dispose()
+            {
+                foreach (EventSource eventSource in this.eventSources)
+                {
+                    this.DisableEvents(eventSource);
+                }
+
+                base.Dispose();
+                GC.SuppressFinalize(this);
+            }
+
+            protected override void OnEventSourceCreated(EventSource eventSource)
+            {
+                if (eventSource?.Name == EventSourceName)
+                {
+                    this.eventSources.Add(eventSource);
+                    this.EnableEvents(eventSource, EventLevel.Verbose, (EventKeywords)(-1));
+                }
+
+                base.OnEventSourceCreated(eventSource);
+            }
+
+            protected override void OnEventWritten(EventWrittenEventArgs eventData)
+            {
+                string message = EventSourceEventFormatting.Format(eventData);
+                TelemetryDebugWriter.WriteMessage($"{eventData.EventSource.Name} - EventId: [{eventData.EventId}], EventName: [{eventData.EventName}], Message: [{message}]");
+            }
+        }
     }
 }

sdk/monitor/Microsoft.OpenTelemetry.Exporter.AzureMonitor/src/AzureMonitorTraceExporter.cs

@@ -47,7 +47,7 @@ public override ExportResult Export(in Batch<Activity> batch)
             }
             catch (Exception ex)
             {
-                AzureMonitorTraceExporterEventSource.Log.Write($"FailedToExport{EventLevelSuffix.Error}", ex.LogAsyncException());
+                AzureMonitorExporterEventSource.Log.Write($"FailedToExport{EventLevelSuffix.Error}", ex.LogAsyncException());
                 return ExportResult.Failure;
             }
         }

sdk/monitor/Microsoft.OpenTelemetry.Exporter.AzureMonitor/src/AzureMonitorTransmitter.cs

@@ -57,7 +57,7 @@ public async ValueTask<int> TrackAsync(IEnumerable<TelemetryItem> telemetryItems
                     // TODO: Network issue. Send Telemetry Items To Storage
                 }
 
-                AzureMonitorTraceExporterEventSource.Log.Write($"FailedToSend{EventLevelSuffix.Error}", ex.LogAsyncException());
+                AzureMonitorExporterEventSource.Log.Write($"FailedToSend{EventLevelSuffix.Error}", ex.LogAsyncException());
             }
 
             return itemsAccepted;

sdk/monitor/Microsoft.OpenTelemetry.Exporter.AzureMonitor/src/ConnectionString/ConnectionStringParser.cs

@@ -40,7 +40,7 @@ public static void GetValues(string connectionString, out string instrumentation
             }
             catch (Exception ex)
             {
-                AzureMonitorTraceExporterEventSource.Log.Write($"ConnectionStringError{EventLevelSuffix.Error}", ex);
+                AzureMonitorExporterEventSource.Log.Write($"ConnectionStringError{EventLevelSuffix.Error}", ex);
                 throw new InvalidOperationException("Connection String Error: " + ex.Message, ex);
             }
         }

sdk/monitor/Microsoft.OpenTelemetry.Exporter.AzureMonitor/src/Microsoft.OpenTelemetry.Exporter.AzureMonitor.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <Description>An OpenTelemetry .NET exporter that exports to Azure Monitor</Description>
     <AssemblyTitle>AzureMonitor OpenTelemetry Exporter</AssemblyTitle>
@@ -23,6 +23,7 @@
     <Compile Include="$(AzureCoreSharedSources)HttpMessageSanitizer.cs" Link="Shared\%(RecursiveDir)\%(Filename)%(Extension)" />
     <Compile Include="$(AzureCoreSharedSources)TaskExtensions.cs" Link="Shared\%(RecursiveDir)\%(Filename)%(Extension)" />
     <Compile Include="$(AzureCoreSharedSources)OperationHelpers.cs" Link="Shared\%(RecursiveDir)\%(Filename)%(Extension)" />
+    <Compile Include="$(AzureCoreSharedSources)EventSourceEventFormatting.cs" Link="Shared\%(RecursiveDir)\%(Filename)%(Extension)" />
   </ItemGroup>
 
   <Import Project="$(MSBuildThisFileDirectory)..\..\..\core\Azure.Core\src\Azure.Core.props" />

sdk/monitor/Microsoft.OpenTelemetry.Exporter.AzureMonitor/src/NDJsonWriter.cs

@@ -33,6 +33,13 @@ public Memory<byte> ToBytes()
             return Stream.ToArray();
         }
 
+        public override string ToString()
+        {
+            Stream.Position = 0;
+            using var streamReader = new StreamReader(Stream);
+            return streamReader.ReadToEnd();
+        }
+
         public void Dispose()
         {
             Stream?.Dispose();

sdk/monitor/Microsoft.OpenTelemetry.Exporter.AzureMonitor/src/SdkVersionUtils.cs

@@ -26,7 +26,7 @@ private static string GetSdkVersion()
             }
             catch (Exception ex)
             {
-                AzureMonitorTraceExporterEventSource.Log.Write($"SdkVersionCreateFailed{EventLevelSuffix.Warning}", ex);
+                AzureMonitorExporterEventSource.Log.Write($"SdkVersionCreateFailed{EventLevelSuffix.Warning}", ex);
                 return null;
             }
         }

sdk/monitor/Microsoft.OpenTelemetry.Exporter.AzureMonitor/src/TelemetryDebugWriter.cs

@@ -0,0 +1,36 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+using System.Diagnostics;
+
+namespace Microsoft.OpenTelemetry.Exporter.AzureMonitor
+{
+    internal class TelemetryDebugWriter
+    {
+        internal static void WriteMessage(string message)
+        {
+            if (message == null)
+            {
+                return;
+            }
+
+            if (Debugger.IsAttached && Debugger.IsLogging())
+            {
+                Debugger.Log(0, null,  message);
+            }
+        }
+
+        internal static void WriteTelemetry(NDJsonWriter content)
+        {
+            if (content == null)
+            {
+                return;
+            }
+
+            if (Debugger.IsAttached && Debugger.IsLogging())
+            {
+                Debugger.Log(0, null, content.ToString());
+            }
+        }
+    }
+}