是什麼導致 OWIN 管道中的 OperationCanceledException？

我OperationCanceledException在我的 API 日誌中發現了很多 s。我認為這與高負載條件有關，但這可能只是因為在高負載下有更多的呼叫，因此有更多的異常。異常的堆棧跟踪沒有到達任何控制器程式碼；它通過我的一些 OWIN 中間件，但在到達任何控制器之前就死了。對於對不同 API 端點的許多呼叫，它是相同的堆棧跟踪：

System.OperationCanceledException: The operation was canceled.
  at System.Threading.CancellationToken.ThrowOperationCanceledException()
  at System.Net.Http.HttpContentExtensions.<ReadAsAsyncCore>d__0`1.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.ModelBinding.FormatterParameterBinding.<ExecuteBindingAsyncCore>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.Web.Http.Controllers.HttpActionBinding.<ExecuteBindingAsyncCore>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.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__2.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.Filters.AuthorizationFilterAttribute.<ExecuteAuthorizationFilterAsyncCore>d__2.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.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.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 MyDomain.Api.Handlers.ApiCultureHandler.<SendAsync>d__0.MoveNext() in D:\Bamboo\xml-data\build-dir\API-R5V3-JOB1\src\Api\Handlers\ApiCultureHandler.cs:line 50
--- 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.HttpServer.<SendAsync>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.Http.Owin.HttpMessageHandlerAdapter.<InvokeCore>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 Microsoft.Owin.Cors.CorsMiddleware.<Invoke>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 Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.IntegratedPipelineContextStage.<RunApp>d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
  at Microsoft.Owin.Security.Infrastructure.AuthenticationMiddleware`1.<Invoke>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 Microsoft.Owin.Security.Infrastructure.AuthenticationMiddleware`1.<Invoke>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 DependencyResolution.Api.Middleware.AuditLogMiddleware.<Invoke>d__1.MoveNext() in D:\Bamboo\xml-data\build-dir\API-R5V3-JOB1\src\DependencyResolution\Api\Middleware\AuditLogMiddleware.cs:line 23
--- 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 DependencyResolution.Api.Middleware.ShardingMiddleware.<Invoke>d__2.MoveNext() in D:\Bamboo\xml-data\build-dir\API-R5V3-JOB1\src\DependencyResolution\Api\Middleware\ShardingMiddleware.cs:line 77
--- 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 DependencyResolution.Api.Middleware.StructureMapMiddleware.<Invoke>d__2.MoveNext() in D:\Bamboo\xml-data\build-dir\API-R5V3-JOB1\src\DependencyResolution\Api\Middleware\StructureMapMiddleware.cs:line 29
--- 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 DependencyResolution.Api.Middleware.ExceptionHandlerMiddleware.<Invoke>d__3.MoveNext() in D:\Bamboo\xml-data\build-dir\API-R5V3-JOB1\src\DependencyResolution\Api\Middleware\ExceptionHandlerMiddleware.cs:line 33

這非常令人不安，因為我不確定如何調試它。

其他可能有用的資訊：在這些錯誤發生時，我的一個 API 伺服器在 CPU 使用率方面表現出我稱之為“Bart Simpson”的模式。CPU 會在大約 20-30 秒內達到 95-100% 的範圍，然後會在另外 20-30 秒內下降到 5-10%，然後再次恢復。循環無限重複。因為我們在生產中，所以我沒有時間進一步調查，我殺死了那個伺服器，讓我們的自動縮放規則啟動一個新伺服器，然後它工作正常。但我不能保證 Bart Simpson 模式不會影響我們啟動的任何其他 API 伺服器，我也不知道是什麼原因造成的。

有任何想法嗎？

由於呼叫堆棧中的程式碼中沒有其他錯誤，因此這可能是誤報。如果客戶端在伺服器響應之前關閉連接，則操作將被取消。例如，假設您的客戶端有一個心跳端點，它每 5 秒呼叫一次，呼叫需要 250 毫秒。每次客戶端關閉時，有 5% 的機會取消操作。有許多正常情況下，客戶端可能會在收到響應之前切斷連接。OperationCanceledException 本身不應引起警報。但是，請務必考慮與客戶數量和您的特定應用相關的頻率。

引用自：https://stackoverflow.com/questions/47959800