WebAPI中的TaskScheduler.UnobservedTaskException取消了该操作

Question

最近我在我的后端API应用程序中为每个UnobservedTaskException添加了错误记录.原因是某些API调用会执行其他任务,这些任务在我返回结果后完成,这就是为什么我无法跟踪操作(web api调用)级别的错误.

现在我得到了很多"操作被取消"的例外,不知道如何处理它.我甚至不确定这个异常是由我的API调用执行的任务引起的.

这是堆栈:

System.OperationCanceledException: The operation was canceled.
   at System.Threading.CancellationToken.ThrowIfCancellationRequested()
   at System.Web.Http.WebHost.HttpControllerHandler.<WriteBufferedResponseContentAsync>d__1b.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Web.Http.WebHost.HttpControllerHandler.<CopyResponseAsync>d__7.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Web.Http.WebHost.HttpControllerHandler.<ProcessRequestAsyncCore>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Web.TaskAsyncHelper.EndTask(IAsyncResult ar)
   at System.Web.HttpApplication.CallHandlerExecutionStep.OnAsyncHandlerCompletion(IAsyncResult ar)

任何想法如何调试呢？

Answer 1

任务取消异常通常来自中止请求的任务.我们正在跟踪将在5.2中修复的错误,这些错误将不会出现在异常记录器中.所以通常你可以放心地忽略这些.

您可以在https://www.myget.org/gallery/aspnetwebstacknightly上获取每晚构建,以验证这可以解决您的问题.

以下是该错误的链接:http://aspnetwebstack.codeplex.com/workitem/1797