Question

我正在尝试将现有网站从Rebus 0.45升级到Rebus 2.0，并遇到System.Web.ThreadContext.AssociateWithCurrentThread与空引用崩溃的问题。我完全不知道为什么，所以我正在寻找可以寻找的可能原因。

我唯一的跟踪是Windows事件日志，它在尝试发送消息时注册以下内容：

An unhandled exception occurred and the process was terminated.

Application ID: /LM/W3SVC/1/ROOT/website

Process ID: 14460

Exception: System.NullReferenceException

Message: Object reference not set to an instance of an object.

StackTrace:    at System.Web.ThreadContext.AssociateWithCurrentThread(Boolean setImpersonationContext)
   at System.Web.HttpApplication.OnThreadEnterPrivate(Boolean setImpersonationContext)
   at System.Web.LegacyAspNetSynchronizationContext.CallCallbackPossiblyUnderLock(SendOrPostCallback callback, Object state)
   at System.Web.LegacyAspNetSynchronizationContext.CallCallback(SendOrPostCallback callback, Object state)
   at System.Web.LegacyAspNetSynchronizationContext.Post(SendOrPostCallback callback, Object state)
   at System.Threading.Tasks.SynchronizationContextAwaitTaskContinuation.PostAction(Object state)
   at System.Threading.Tasks.AwaitTaskContinuation.RunCallback(ContextCallback callback, Object state, Task& currentTask)
--- End of stack trace from previous location where exception was thrown ---
   at System.Threading.Tasks.AwaitTaskContinuation.<>c.<ThrowAsyncIfNecessary>b__18_0(Object s)
   at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(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.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
   at System.Threading.ThreadPoolWorkQueue.Dispatch()
   at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()

该网站运行带有Castle Windsor依赖注入器的ASP.NET MVC 3.0，并使用Rebus.SqlServer作为单向客户端进行传输设置：

var busConfigurer = Configure.With(new CastleWindsorContainerAdapter(container))
  .Logging(l => l.Use(new RebusLoggerFactory()))
  .Routing(t => t.TypeBased().AddEndpointMappingsFromAppConfig())
  .Subscriptions(s => s.StoreInSqlServer(dbConnectionString, "RebusSubscriptions_v2"))
  .Transport(t => t.UseSqlServerAsOneWayClient(dbConnectionString, "RebusMessages_v2"))
  Start();

IIS设置为＆＃34; .NET 4.5＆＃34;应用程序池。

网站启动并且总线记录：

- Supplied connection string will be modified to enable MARS
- Database already contains a table named 'RebusMessages_v2' - will not create anything
- Supplied connection string will be modified to enable MARS
- Starting periodic task 'CleanupTrackedErrors' with interval 00:01:00
- Starting bus 1
- Started

稍后会通过Rebus发送一条消息，记录：

- Sending SubmissionCreatedEvent -> SelfService.Service.input

......并且热潮！整个应用程序崩溃。

在发送消息之前，应用程序已与NHibernate交互以存储有关操作的详细信息。

更新

通过将Bus.Send(msg)更改为Bus.Send(msg).Start()，我可以同步触发相同的错误，并在Visual Studio中进行调试时获得以下堆栈跟踪：

Exception thrown: 'System.NullReferenceException' in System.Web.dll
Exception thrown: 'System.NullReferenceException' in mscorlib.dll
System.Transactions Critical: 0 : 
<TraceRecord xmlns="http://schemas.microsoft.com/2004/10/E2ETraceEvent/TraceRecord" Severity="Critical"><TraceIdentifier>http://msdn.microsoft.com/TraceCodes/System/ActivityTracing/2004/07/Reliability/Exception/Unhandled</TraceIdentifier><Description>Unhandled exception</Description><AppDomain>/LM/W3SVC/1/ROOT/website-2-131225642632547395</AppDomain>
<Exception><ExceptionType>System.NullReferenceException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</ExceptionType><Message>Object reference not set to an instance of an object.</Message><StackTrace>   at System.Web.ThreadContext.AssociateWithCurrentThread(Boolean setImpersonationContext)
   at System.Web.HttpApplication.OnThreadEnterPrivate(Boolean setImpersonationContext)
   at System.Web.LegacyAspNetSynchronizationContext.CallCallbackPossiblyUnderLock(SendOrPostCallback callback, Object state)
   at System.Web.LegacyAspNetSynchronizationContext.CallCallback(SendOrPostCallback callback, Object state)
   at System.Web.LegacyAspNetSynchronizationContext.Post(SendOrPostCallback callback, Object state)
   at System.Threading.Tasks.SynchronizationContextAwaitTaskContinuation.PostAction(Object state)
   at System.Threading.Tasks.AwaitTaskContinuation.RunCallback(ContextCallback callback, Object state, Task&amp;amp; currentTask)
--- End of stack trace from previous location where exception was thrown ---
   at System.Threading.Tasks.AwaitTaskContinuation.&amp;lt;&amp;gt;c.&amp;lt;ThrowAsyncIfNecessary&amp;gt;b__18_0(Object s)
   at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(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.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
   at System.Threading.ThreadPoolWorkQueue.Dispatch()
   at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()</StackTrace><ExceptionString>System.NullReferenceException: Object reference not set to an instance of an object.
   at System.Web.ThreadContext.AssociateWithCurrentThread(Boolean setImpersonationContext)
   at System.Web.HttpApplication.OnThreadEnterPrivate(Boolean setImpersonationContext)
   at System.Web.LegacyAspNetSynchronizationContext.CallCallbackPossiblyUnderLock(SendOrPostCallback callback, Object state)
   at System.Web.LegacyAspNetSynchronizationContext.CallCallback(SendOrPostCallback callback, Object state)
   at System.Web.LegacyAspNetSynchronizationContext.Post(SendOrPostCallback callback, Object state)
   at System.Threading.Tasks.SynchronizationContextAwaitTaskContinuation.PostAction(Object state)
   at System.Threading.Tasks.AwaitTaskContinuation.RunCallback(ContextCallback callback, Object state, Task&amp;amp; currentTask)
--- End of stack trace from previous location where exception was thrown ---
   at System.Threading.Tasks.AwaitTaskContinuation.&amp;lt;&amp;gt;c.&amp;lt;ThrowAsyncIfNecessary&amp;gt;b__18_0(Object s)
   at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(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.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
   at System.Threading.ThreadPoolWorkQueue.Dispatch()
   at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()</ExceptionString></Exception></TraceRecord>

更新II

用Bus.Publish(msg)替换bus.Advanced.Routing.Send("SelfService.Service.input", msg)有效。显然，订阅/路由的东西有问题，因为Send(...)会绕过它。

更新III

显然在web.config中添加<httpRuntime targetFramework="4.6" ...解决了这个问题（到目前为止，它似乎仍然有点不稳定）。 web.config已经有<compilation ... targetFramework="4.6">：

  <system.web>
    <httpRuntime targetFramework="4.6" maxRequestLength="5000" requestValidationMode="2.0" />
    <compilation debug="true" targetFramework="4.6">
      <assemblies>...</assemblies>
    </compilation>
    <pages validateRequest="false">
      <namespaces>...</namespaces>
    </pages>
  </system.web>

Answer 1

修复原来是为了确保网站运行的是.NET 4.5或更高版本：

<system.web>
  <httpRuntime targetFramework="4.6" />
  <compilation targetFramework="4.6">
    ...
  </compilation>
</system.web>

显然，ASP.NET团队在.NET 4.5中使ASP.NET更具任务感知能力。

.NET异步核心

1 个答案: