Question

我们在Beta HyperV环境中的MVC AsyncController上遇到了TimeoutException。在本地调试时一切正常，但是当我们部署到预生产环境时，我们会收到此错误：

[TimeoutException：操作已超时。] System.Web.Mvc.Async.WrappedAsyncResult`1.End（）+129 System.Web.Mvc.Async。＆lt;＆gt; c_ DisplayClass39.b _38（IAsyncResult asyncResult）+23 System.Web.Mvc.Async。＆lt;＆gt; c_ DisplayClass33.b _2d（）+125 System.Web.Mvc.Async。＆lt;＆gt; c_ DisplayClass49.b _43（）+452 System.Web.Mvc.Async。＆lt;＆gt; c_ DisplayClass49.b _43（）+452 System.Web.Mvc.Async。＆lt;＆gt; c_ DisplayClass49.b _43（）+452 System.Web.Mvc.Async。＆lt;＆gt; c_ DisplayClass31.b _30（IAsyncResult asyncResult）+15 System.Web.Mvc.Async。＆lt;＆gt; c_ DisplayClass24.b _1a（）+31 System.Web.Mvc.Async。＆lt;＆gt; c_ DisplayClass1f.b _1c（IAsyncResult asyncResult）+230 System.Web.Mvc。＆lt;＆gt; c_ DisplayClass17.b _12（IAsyncResult asyncResult）+28 System.Web.Mvc.Async。＆lt;＆gt; c_ DisplayClass4.b _3（IAsyncResult ar）+20 System.Web.Mvc.AsyncController.EndExecuteCore（IAsyncResult asyncResult）+53 System.Web.Mvc.Async。＆lt;＆gt; c_ DisplayClass4.b _3（IAsyncResult ar）+20 System.Web.Mvc。＆lt;＆gt; c_ DisplayClass8.b _3（IAsyncResult asyncResult）+42 System.Web.Mvc.Async。＆lt;＆gt; c_ DisplayClass4.b _3（IAsyncResult ar）+20 System.Web.CallHandlerExecutionStep.OnAsyncHandlerCompletion（IAsyncResult ar）+136

    [OutputCache(Duration = 0, NoStore = true, VaryByParam = "")]
            public void IndexAsync()
            {
                using (var context = Repository.CreateContext().CreateUnitOfWork())
                {
                    user = context.Users.Single(u => u.Username == User.Identity.Name);

                        AsyncManager.OutstandingOperations.Increment();

                        ThreadPool.QueueUserWorkItem(o => {
                            var sync = myService.DoThingsAsync(user);
                            sync.AsyncWaitHandle.WaitOne();
                            AsyncManager.OutstandingOperations.Decrement();  
                        });
                }
            }

/// IndexCompleted is never called
     public ActionResult IndexCompleted(string property)
            {
                using (var context = Repository.CreateContext().CreateUnitOfWork())
                {
                    var user = context.Users.Single(u => u.Username == User.Identity.Name);

                    var model = new MyViewModel
                    {
                        ModelProperty = user.Property
                    };

                    return View("Index", model);
                }
            }

出现此错误的可能原因是什么？

Answer 1

这是异步操作所花费的时间超过配置的AsyncTimeout值（默认为45秒）时抛出的异常。您可以通过使用AsyncTimeout属性修饰ActionMethod来显式控制此值。例如，要将异步超时设置为整分钟：

[AsyncTimeout(60000)]
public void IndexAsync()
{
   ...
}

您也可以使用NoAsyncTimeout属性，但是您很容易受到从未完成的异步操作的影响，并使您的Web请求处于不稳定状态。

HyperV环境中AsyncController的TimeoutException

1 个答案: