异步 WCF 服务超时
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【中文标题】异步 WCF 服务超时【英文标题】：Asynchronous WCF service timing out 【发布时间】：2012-07-16 17:51:14 【问题描述】：我们有一个异步 WCF 服务操作，它从我们系统的所有不同组件获取日志文件并将它们发送到客户端。如果其中一个组件无法正常工作，这可能需要一段时间，因此如果此功能不会超时，那就太好了，但它也不应该导致客户端挂起。
我对异步 WCF 服务的理解是，当客户端向服务器请求某些东西时，服务器会立即回复一条消息说：“我在做。继续做你自己的事情，我会通知你的当我完成时。”然后释放连接以供客户端发出其他请求，同时服务器启动一个新线程来完成其大部分工作。当服务器完成后，它会向客户端发送一条带有结果的消息。正因为如此，服务器和客户端之间的连接是免费的，无论服务器花费多长时间，连接都不应超时。这是正确的吗？
如果是这种情况，那么我们的服务就没有按预期工作。当我测试该服务时，只要不到一分钟，它就可以按预期工作。但是，如果我强制它花费更长的时间，客户端会抛出 TimeoutException。既然服务是异步的，不应该永远不超时吗？如果是这样，我错过了什么？
我们使用此页面作为指南编写了我们的异步服务： http://code.msdn.microsoft.com/windowsdesktop/How-to-Implement-a-WCF-2090bec8
这是我的代码。这是服务合同：
[ServiceContract(CallbackContract = typeof(IInformationServiceCallBack), SessionMode = SessionMode.Required)]
public interface IInformationService
//snip...
[OperationContract(AsyncPattern=true)]
[FaultContract(typeof(LogFileFault))]
IAsyncResult BeginGetLogFiles(LogFileRequest[] logfileRequests,
AsyncCallback callback, object state);
LogFile[] EndGetLogFiles(IAsyncResult result);
//snip...
这是服务实现：
[ServiceBehavior(ConcurrencyMode = ConcurrencyMode.Multiple, InstanceContextMode = InstanceContextMode.PerSession, UseSynchronizationContext=false)]
public class InformationServiceImpl : IInformationService, IDisposable
//snip...
public IAsyncResult BeginGetLogFiles(LogFileRequest[] logfileRequests,
AsyncCallback callback, object state)
var task = Task<LogFile[]>.Factory.StartNew((x) =>
return GetLogFilesHelper(logfileRequests);
, state);
return task.ContinueWith(res => callback(task));
public LogFile[] EndGetLogFiles(IAsyncResult result)
var castResult = result as Task<LogFile[]>;
return castResult.Result;
private LogFile[] GetLogFilesHelper(LogFileRequest[] logfileRequests)
//Long-running method that gets the log files
//snip...
这是客户端代码：
public class InformationServiceConnection : WcfDurableConnection<IInformationService> //WcfDurableConnection is one of our internal classes
//snip...
public void GetServiceLogFiles(Action<LogFile[], WcfCommandResult> callback)
var logfileRequests = new LogFileRequest[]
new LogFileRequest(/* snip */),
new LogFileRequest(/* snip */),
new LogFileRequest(/* snip */),
new LogFileRequest(/* snip */)
;
ExecuteTask(x =>
LogFile[] logfile = null;
WcfCommandResult wcfResult = null;
var asyncCallback = new AsyncCallback((result) =>
logfile = Channel.EndGetLogFiles(result);
callback(logfile, wcfResult);
);
wcfResult = RunCommand(y =>
Channel.BeginGetLogFiles(logfileRequests, asyncCallback, null);
, x);
);
/* ExecuteTask and RunCommand are both methods that take care of
* multithreading issues for us. I included their code below in
* case they make a difference, but the code I'm most interested
* in is the GetServiceLogFiles method above. */
//snip...
protected CancellationTokenSource ExecuteTask(Action<CancellationToken> action)
CancellationTokenSource tokenSource = new CancellationTokenSource();
ManualResetEvent lastTask;
ManualResetEvent thisTask;
lock (_objectLock)
lastTask = _syncTask;
thisTask = new ManualResetEvent(false);
_syncTask = thisTask;
tokenSource.Token.Register(x => ((ManualResetEvent)x).Set(), thisTask);
var task = Task.Factory.StartNew((x) =>
try
lastTask.WaitOne();
action((CancellationToken)x);
catch (Exception e)
LogUtility.Error(e);
finally
thisTask.Set();
, tokenSource.Token, tokenSource.Token).HandleExceptions();
return tokenSource;
//snip...
protected WcfCommandResult RunCommand(Action<CancellationToken> action, CancellationToken token, bool isRestarting = false)
return RunCommand(x => action(x); return true; , token, isRestarting);
protected WcfCommandResult RunCommand(Func<CancellationToken, bool> action, CancellationToken token, bool isRestarting = false)
WcfCommandResult result = new WcfCommandResult();
lock (_reconnectionLock)
if (_reconnecting && !isRestarting)
result.Completed = false;
return result;
lock (_channelLock)
if (Channel == null && !_closing)
token.ThrowIfCancellationRequested();
Channel = GetNewChannel();
var iChannel = (IClientChannel)Channel;
var initResult = Initialize(token, false);
if (initResult.Completed)
Connected = true;
LogUtility.Info(string.Format("Connected to 0 at 1", ServiceName, iChannel.RemoteAddress));
else
LogUtility.Info(string.Format("Failed to connect to 0 at 1", ServiceName, iChannel.RemoteAddress));
try
var channel = Channel;
token.ThrowIfCancellationRequested();
if (channel != null)
result.Completed = action(token);
catch (FaultException e)
result.Exception = e;
result.Detail = e.GetDetail<DurableFault>();
LogUtility.Error(result.Exception);
catch (CommunicationException e)
Connected = false;
result.Exception = e;
IClientChannel channel = ((IClientChannel)Channel);
if (channel != null)
channel.Abort();
Channel = null;
if (!_reconnecting)
LogUtility.Error(result.Exception);
catch (TimeoutException e)
Connected = false;
result.Exception = e;
IClientChannel channel = ((IClientChannel)Channel);
if (channel != null)
channel.Abort();
Channel = null;
if (!_reconnecting)
LogUtility.Error(result.Exception);
catch (NullReferenceException e)
Connected = false;
result.Exception = e;
IClientChannel channel = ((IClientChannel)Channel);
if (channel != null)
channel.Abort();
Channel = null;
if (!_reconnecting)
LogUtility.WriteException("Channel is null, it has either been disposed or not setup, call BeginSetupUser to create a new channel", e);
catch (ObjectDisposedException e)
Connected = false;
result.Exception = e;
IClientChannel channel = ((IClientChannel)Channel);
if (channel != null)
channel.Abort();
Channel = null;
if (!_reconnecting)
LogUtility.Error(result.Exception);
catch (InvalidOperationException e)
Connected = false;
result.Exception = e;
IClientChannel channel = ((IClientChannel)Channel);
if (channel != null)
channel.Abort();
Channel = null;
if (!_reconnecting)
LogUtility.Error(result.Exception);
return result;
//snip...
【问题讨论】：
【参考方案1】：即使是异步调用，您的配置文件中也设置了超时。如果需要很长时间才能响应，您可能应该增加它。我认为默认是 1 分钟。在 Visual Studio 中，转到工具-> WCF 服务配置编辑器以轻松更改值。
如果您想查看配置的外观，这也可能对您有所帮助：Increasing the timeout value in a WCF service
您可以在该配置文件或后面的代码中设置它。
【讨论】：
这是有道理的。我会考虑按照您的建议更改超时期限。感谢您的回复！ 对于那些稍后阅读本文的人：本文解释了如何以编程方式更改更改超时值：codeproject.com/Articles/28265/WCF-Operation-Timeout-Exception以上是关于异步 WCF 服务超时的主要内容，如果未能解决你的问题，请参考以下文章