【Azure 应用服务】App Service频繁出现 Microsoft.WindowsAzure.Diagnostics.DiagnosticMonitorTraceListener 异常分析

问题描述

在使用App Service的过程中，发现应用频繁出现503错误，通过Kudu站点获取到Logfiles。

在 Eventlog.xml 文件中，发现大量的 Microsoft.WindowsAzure.Diagnostics.DiagnosticMonitorTraceListener 异常，并且引起 w3wp.exe 进程终止。

<Event>
<System>
<Provider Name=".NET Runtime"/>
<EventID>1026</EventID>
<Level>1</Level>
<Task>0</Task>
<Keywords>Keywords</Keywords>
<TimeCreated SystemTime="2022-09-22T09:52:50Z"/>
<EventRecordID>421882843</EventRecordID>
<Channel>Application</Channel>
<Computer>RD0003FF0C13B3</Computer>
<Security/>
</System>
<EventData>
<Data>Application: w3wp.exe Framework Version: v4.0.30319 Description: The process was terminated due to an unhandled exception. Exception Info: System.Configuration.ConfigurationErrorsException at System.Diagnostics.TraceUtils.GetRuntimeObject(System.String, System.Type, System.String) at System.Diagnostics.TypedElement.BaseGetRuntimeObject() at System.Diagnostics.ListenerElement.GetRuntimeObject() at System.Diagnostics.ListenerElementsCollection.GetRuntimeObject() at System.Diagnostics.TraceInternal.get_Listeners() at System.Diagnostics.TraceInternal.WriteLine(System.String) at System.Diagnostics.Debug.WriteLine(System.String) at Microsoft.Web.Compilation.Snapshots.SnapshotHelper.TakeSnapshotTimerCallback(System.Object) at System.Threading.TimerQueueTimer.CallCallbackInContext(System.Object) at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean) at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean) at System.Threading.TimerQueueTimer.CallCallback() at System.Threading.TimerQueueTimer.Fire() at System.Threading.TimerQueue.FireNextTimers() at System.Threading.TimerQueue.AppDomainTimerCallback(Int32) </Data>
</EventData>
</Event>
<Event>
<System>
<Provider Name="ASP.NET 4.0.30319.0"/>
<EventID>1325</EventID>
<Level>1</Level>
<Task>0</Task>
<Keywords>Keywords</Keywords>
<TimeCreated SystemTime="2022-09-22T10:02:53Z"/>
<EventRecordID>422485625</EventRecordID>
<Channel>Application</Channel>
<Computer>RD0003FF0C13B3</Computer>
<Security/>
</System>
<EventData>
<Data>An unhandled exception occurred and the process was terminated. Application ID: /LM/W3SVC/152666399/ROOT Process ID: 6092 Exception: System.Configuration.ConfigurationErrorsException Message: Couldn't find type for class Microsoft.WindowsAzure.Diagnostics.DiagnosticMonitorTraceListener, Microsoft.WindowsAzure.Diagnostics, Version=2.8.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35. StackTrace: at System.Diagnostics.TraceUtils.GetRuntimeObject(String className, Type baseType, String initializeData) at System.Diagnostics.TypedElement.BaseGetRuntimeObject() at System.Diagnostics.ListenerElement.GetRuntimeObject() at System.Diagnostics.ListenerElementsCollection.GetRuntimeObject() at System.Diagnostics.TraceInternal.get_Listeners() at System.Diagnostics.TraceInternal.WriteLine(String message) at System.Diagnostics.Debug.WriteLine(String message) at Microsoft.Web.Compilation.Snapshots.SnapshotHelper.TakeSnapshotTimerCallback(Object stateInfo) at System.Threading.TimerQueueTimer.CallCallbackInContext(Object state) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx) at System.Threading.TimerQueueTimer.CallCallback() at System.Threading.TimerQueueTimer.Fire() at System.Threading.TimerQueue.FireNextTimers() at System.Threading.TimerQueue.AppDomainTimerCallback(Int32 id)</Data>
</EventData>
</Event>

 在启用了 Proactive Crash Monitoring in Azure App Service 后，当应用再次应为没有处理的异常(24小时内发生3次)就会自动抓取Memory DUMP进行分析。完整的异常日志为：

========================================================
 Dump Analysis for w3wp__xxxxxxxx__PID__9644__Date__09_22_2022__Time_02_59_27AM__239__Second_Chance_Exception_E0434352.dmp
========================================================
Thread 7984
ExitCode E0434352
ExitCodeString CLR EXCEPTION
DefaultHostName xxxxxxxxxx.chinacloudsites.cn
Managed Exception = System.Configuration.ConfigurationErrorsException:Couldn't find type for class Microsoft.WindowsAzure.Diagnostics.DiagnosticMonitorTraceListener, Microsoft.WindowsAzure.Diagnostics, Version=2.8.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35.
CallStack - Managed Exception
========================================================
     System.Diagnostics.TraceUtils.GetRuntimeObject(System.String, System.Type, System.String)
     System.Diagnostics.TypedElement.BaseGetRuntimeObject()
     System.Diagnostics.ListenerElement.GetRuntimeObject()
     System.Diagnostics.ListenerElementsCollection.GetRuntimeObject()
     System.Diagnostics.TraceInternal.get_Listeners()
     System.Diagnostics.TraceInternal.WriteLine(System.String)
     System.Diagnostics.Debug.WriteLine(System.String)
     Microsoft.Web.Compilation.Snapshots.SnapshotHelper.TakeSnapshotTimerCallback(System.Object)
     System.Threading.TimerQueueTimer.CallCallbackInContext(System.Object)
     System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
     System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
     System.Threading.TimerQueueTimer.CallCallback()
     System.Threading.TimerQueueTimer.Fire()
     System.Threading.TimerQueue.FireNextTimers()
     System.Threading.TimerQueue.AppDomainTimerCallback(Int32)
CallStack - Crashing Thread
========================================================
     HelperMethodFrame
     System.Diagnostics.TraceUtils.GetRuntimeObject(System.String, System.Type, System.String)
     System.Diagnostics.TypedElement.BaseGetRuntimeObject()
     System.Diagnostics.ListenerElement.GetRuntimeObject()
     System.Diagnostics.ListenerElementsCollection.GetRuntimeObject()
     System.Diagnostics.TraceInternal.get_Listeners()
     System.Diagnostics.TraceInternal.WriteLine(System.String)
     System.Diagnostics.Debug.WriteLine(System.String)
     Microsoft.Web.Compilation.Snapshots.SnapshotHelper.TakeSnapshotTimerCallback(System.Object)
     System.Threading.TimerQueueTimer.CallCallbackInContext(System.Object)
     System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
     System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
     System.Threading.TimerQueueTimer.CallCallback()
     System.Threading.TimerQueueTimer.Fire()
     System.Threading.TimerQueue.FireNextTimers()
     System.Threading.TimerQueue.AppDomainTimerCallback(Int32)
     DebuggerU2MCatchHandlerFrame
     ContextTransitionFrame
     DebuggerU2MCatchHandlerFrame

 Native Call Stack
========================================================
KERNELBASE!RaiseException
clr!RaiseTheExceptionInternalOnly
clr!IL_Throw
mscorlib_ni
mscorlib_ni
mscorlib_ni
mscorlib_ni
mscorlib_ni
mscorlib_ni
clr!CallDescrWorkerInternal
clr!CallDescrWorkerWithHandler
clr!MethodDescCallSite::CallTargetWorker
clr!AppDomainTimerCallback_Worker
clr!ManagedThreadBase_DispatchInner
clr!ManagedThreadBase_DispatchMiddle
clr!ManagedThreadBase_DispatchOuter
clr!ManagedThreadBase_DispatchInCorrectAD
clr!Thread::DoADCallBack
clr!ManagedThreadBase_DispatchInner
clr!ManagedThreadBase_DispatchMiddle
clr!ManagedThreadBase_DispatchOuter
clr!ManagedThreadBase_FullTransitionWithAD
clr!AppDomainTimerCallback
clr!ThreadpoolMgr::AsyncTimerCallbackCompletion
clr!UnManagedPerAppDomainTPCount::DispatchWorkItem
clr!ThreadpoolMgr::ExecuteWorkRequest
clr!ThreadpoolMgr::WorkerThreadStart
clr!Thread::intermediateThreadProc
kernel32!BaseThreadInitThunk
ntdll!__RtlUserThreadStart
ntdll!_RtlUserThreadStart

这个问题是什么原因呢？

问题解答

在Eventlog.xml文件中，已经发现了此异常的根本原因是：Couldn’t find type for class Microsoft.WindowsAzure.Diagnostics.DiagnosticMonitorTraceListener, Microsoft.WindowsAzure.Diagnostics, Culture=neutral, PublicKeyToken=31bf3856ad364e35

这个问题发生的原因是在项目中使用了 ”Microsoft.WindowsAzure.Diagnostics.dll“， 这个 dll 可以在云服务(Azure Cloud Service)中使用，但是它与App Service不相容，不能在App Service中使用。否则，就不停的引发异常导致W3WP.EXE重启。

通过下面两方面来解决这个问题：

1）检查应用项目文件，移除全部 Microsoft.WindowsAzure.Diagnostics.dll 的引用

2）检查应用的 web.config 文件，如果存在 system.diagnostics 中含有 DiagnosticMonitorTraceListener 内容，则全部移除

 <system.diagnostics>
   <trace>
     <listeners>
       <add type="Microsoft.WindowsAzure.Diagnostics.DiagnosticMonitorTraceListener, Microsoft.WindowsAzure.Diagnostics, Culture=neutral, PublicKeyToken=31bf3856ad364e35" name="AzureDiagnostics">
       <filter type="" />
       </add>
     </listeners>
   </trace>
 </system.diagnostics>

操作以上两步骤后，希望能解决因为Couldn’t find type for class Microsoft.WindowsAzure.Diagnostics.DiagnosticMonitorTraceListener 问题。

参考资料

Preventing crashes due to DiagnosticMonitorTraceListener ：https://azure.github.io/AppService/2021/06/09/Apps-on-App-Services-crash-due-to-DiagnosticMonitorTraceListener.html

Proactive Crash Monitoring in Azure App Service ： https://azure.github.io/AppService/2021/03/01/Proactive-Crash-Monitoring-in-Azure-App-Service