[BREAKING CHANGE] DefaultTracing: Removes DefaultTraceListener to disable tracing by default

Microsoft.Azure.Cosmos/src/CosmosClient.cs

@@ -6,6 +6,7 @@ namespace Microsoft.Azure.Cosmos
 {
  using System;
  using System.Collections.Generic;
+ using System.Diagnostics;
  using System.Net;
  using System.Text;
  using System.Threading;
@@ -96,6 +97,8 @@ namespace Microsoft.Azure.Cosmos
  /// <seealso href="https://docs.microsoft.com/azure/cosmos-db/request-units">Request Units</seealso>
  public class CosmosClient : IDisposable
  {
+ private static readonly object defaultTraceLockObject = new object();
+
  private readonly string DatabaseRootUri = Paths.Databases_Root;
  private ConsistencyLevel? accountConsistencyLevel;
  private bool isDisposed = false;
@@ -119,6 +122,15 @@ static CosmosClient()
  // NOTE: Native ServiceInteropWrapper.AssembliesExist has appsettings dependency which are proofed for CTL (native dll entry) scenarios.
  // Revert of this depends on handling such in direct assembly
  ServiceInteropWrapper.AssembliesExist = new Lazy<bool>(() => true);
+
+ Microsoft.Azure.Cosmos.Core.Trace.DefaultTrace.InitEventListener();
+
+ // If a debugger is not attached remove the DefaultTraceListener. 
+ // DefaultTraceListener can cause lock contention leading to availability issues
+ if (!Debugger.IsAttached)
+ {
+ CosmosClient.RemoveDefaultTraceListener();
+ }
  }
 
  /// <summary>
@@ -257,7 +269,7 @@ internal CosmosClient(
  this.ClientContext = ClientContextCore.Create(
  this,
  clientOptions);
- 
+
  this.ClientConfigurationTraceDatum = new ClientConfigurationTraceDatum(this.ClientContext, DateTime.UtcNow);
  }
 
@@ -1033,6 +1045,60 @@ public virtual Task<ResponseMessage> CreateDatabaseStreamAsync(
  });
  }
 
+ /// <summary>
+ /// The DefaultTraceListener is removed from the CosmosClient's TraceSource unless
+ /// a debugger is attached.This prevents possible lock contention which can lead to 
+ /// availability issues by requests waiting on the locks.
+ /// </summary>
+ /// <remarks>
+ /// This is enabled by default when Debugger.IsAttached is true. This makes it
+ /// easier to troubleshoot issues while debugging in Visual Studio.
+ /// </remarks>
+ public static void AddDefaultTraceListener()
+ {
+ lock (CosmosClient.defaultTraceLockObject)
+ {
+ if (Core.Trace.DefaultTrace.TraceSource.Listeners.Count > 0)
+ {
+ foreach (object traceListnerObject in Core.Trace.DefaultTrace.TraceSource.Listeners)
+ {
+ // The TraceSource already has the default trace listener
+ if (traceListnerObject is DefaultTraceListener)
+ {
+ return;
+ }
+ }
+ }
+
+ Microsoft.Azure.Cosmos.Core.Trace.DefaultTrace.TraceSource.Listeners.Add(new DefaultTraceListener());
+ }
+ }
+
+ internal static void RemoveDefaultTraceListener()
+ {
+ lock (CosmosClient.defaultTraceLockObject)
+ {
+ if (Core.Trace.DefaultTrace.TraceSource.Listeners.Count > 0)
+ {
+ List<DefaultTraceListener> removeDefaultTraceListeners = new List<DefaultTraceListener>();
+ foreach (object traceListnerObject in Core.Trace.DefaultTrace.TraceSource.Listeners)
+ {
+ // The TraceSource already has the default trace listener
+ if (traceListnerObject is DefaultTraceListener defaultTraceListener)
+ {
+ removeDefaultTraceListeners.Add(defaultTraceListener);
+ }
+ }
+
+ // Remove all the default trace listeners
+ foreach (DefaultTraceListener defaultTraceListener in removeDefaultTraceListeners)
+ {
+ Core.Trace.DefaultTrace.TraceSource.Listeners.Remove(defaultTraceListener);
+ }
+ }
+ }
+ }
+
  internal virtual async Task<ConsistencyLevel> GetAccountConsistencyLevelAsync()
  {
  if (!this.accountConsistencyLevel.HasValue)

Microsoft.Azure.Cosmos/src/DocumentClient.cs

@@ -646,8 +646,6 @@ internal virtual void Initialize(Uri serviceEndpoint,
  throw new ArgumentNullException("serviceEndpoint");
  }
 
- DefaultTrace.InitEventListener();
-
  this.queryPartitionProvider = new AsyncLazy<QueryPartitionProvider>(async () =>
  {
  await this.EnsureValidClientAsync(NoOpTrace.Singleton);

Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.Tests/Contracts/DotNetSDKAPI.json

@@ -2184,6 +2184,11 @@
  "Attributes": [],
  "MethodInfo": "[Void .ctor(System.String, System.String, Microsoft.Azure.Cosmos.CosmosClientOptions), Void .ctor(System.String, System.String, Microsoft.Azure.Cosmos.CosmosClientOptions)]"
  },
+ "Void AddDefaultTraceListener()": {
+ "Type": "Method",
+ "Attributes": [],
+ "MethodInfo": "Void AddDefaultTraceListener();IsAbstract:False;IsStatic:True;IsVirtual:False;IsGenericMethod:False;IsConstructor:False;IsFinal:False;"
+ },
  "Void Dispose()": {
  "Type": "Method",
  "Attributes": [],

Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.Tests/DefaultTracingTests.cs

@@ -0,0 +1,64 @@
+//------------------------------------------------------------
+// Copyright (c) Microsoft Corporation. All rights reserved.
+//------------------------------------------------------------
+namespace Microsoft.Azure.Cosmos.Tests
+{
+ using System;
+ using System.Diagnostics;
+ using System.Net.Http;
+ using System.Reflection;
+ using System.Threading;
+ using System.Threading.Tasks;
+ using Microsoft.Azure.Cosmos.Core.Trace;
+ using Microsoft.VisualStudio.TestTools.UnitTesting;
+ using Moq;
+
+ [TestClass]
+ public class DefaultTracingTests
+ {
+ [TestMethod]
+ public void DefaultTracingDisabledByDefault()
+ {
+ // Used to just force the CosmosClient static ctor to get called
+ Assert.IsTrue(CosmosClient.numberOfClientsCreated >= 0);
+
+ if (Debugger.IsAttached)
+ {
+ Assert.IsTrue(this.DefaultTraceHasDefaulTraceListener());
+ }
+ else
+ {
+ Assert.IsFalse(this.DefaultTraceHasDefaulTraceListener());
+ }
+ }
+
+ [TestMethod]
+ public void DefaultTracingEnableTest()
+ {
+ Assert.IsFalse(this.DefaultTraceHasDefaulTraceListener());
+ CosmosClient.AddDefaultTraceListener();
+ Assert.IsTrue(this.DefaultTraceHasDefaulTraceListener());
+ CosmosClient.RemoveDefaultTraceListener();
+ Assert.IsFalse(this.DefaultTraceHasDefaulTraceListener());
+ }
+
+ private bool DefaultTraceHasDefaulTraceListener()
+ {
+ if (DefaultTrace.TraceSource.Listeners.Count == 0)
+ {
+ return false;
+ }
+
+ foreach (TraceListener listener in DefaultTrace.TraceSource.Listeners)
+ {
+ if (listener is DefaultTraceListener)
+ {
+ return true;
+ }
+ }
+
+ DefaultTrace.TraceSource.Listeners.Clear();
+ return false;
+ }
+ }
+}

Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.Tests/GatewayStoreModelTest.cs

@@ -60,7 +60,7 @@ void TraceHandler(string message)
  {
  Assert.IsFalse(failedToResolve, "Failure to resolve should happen only once.");
  failedToResolve = true;
- didNotRetryMessage = message.Substring(failedToResolveMessage.Length).Split('\n')[0];
+ didNotRetryMessage = message[failedToResolveMessage.Length..].Split('\n')[0];
  }
 
  if (failedToResolve && message.Contains("NOT be retried") && message.Contains(didNotRetryMessage))
@@ -71,24 +71,36 @@ void TraceHandler(string message)
  Console.WriteLine(message);
  }
 
- DefaultTrace.TraceSource.Listeners.Add(new TestTraceListener { Callback = TraceHandler });
+ TestTraceListener testTraceListener = new TestTraceListener { Callback = TraceHandler };
+ DefaultTrace.TraceSource.Listeners.Add(testTraceListener);
+ DefaultTrace.InitEventListener();
 
  try
  {
- DocumentClient myclient = new DocumentClient(new Uri(accountEndpoint), "base64encodedurl",
- new ConnectionPolicy
- {
- });
+ try
+ {
+ DocumentClient myclient = new DocumentClient(new Uri(accountEndpoint), "base64encodedurl",
+ new ConnectionPolicy
+ {
+ });
 
- await myclient.OpenAsync();
+ await myclient.OpenAsync();
+ }
+ catch
+ {
+ }
+
+ DefaultTrace.TraceSource.Flush();
+
+ // it should fail fast and not into the retry logic.
+ Assert.IsTrue(failedToResolve, "OpenAsync did not fail to resolve. No matching trace was received.");
+ Assert.IsTrue(didNotRetry, "OpenAsync did not fail without retrying. No matching trace was received.");
  }
- catch
+ finally
  {
+
+ DefaultTrace.TraceSource.Listeners.Remove(testTraceListener);
  }
-
- // it should fail fast and not into the retry logic.
- Assert.IsTrue(failedToResolve, "OpenAsync did not fail to resolve. No matching trace was received.");
- Assert.IsTrue(didNotRetry, "OpenAsync did not fail without retrying. No matching trace was received.");
  }
 
  /// <summary>