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我有一个 WPF 应用程序（主机），除其他外，它是具有多个 ServiceHosts 的自托管 WCF（如下所示的示例） 

host= new ServiceHost(typeof(Data));
ServiceEndpoint endpoint = _HostData.AddServiceEndpoint(typeof(IData), _tcpBindingBO, _netTcpAddress + "data");


// add throttle behaviour
ServiceThrottlingBehavior throttle = host.Description.Behaviors.Find<ServiceThrottlingBehavior>();
if (throttle == null)
{
    throttle = new ServiceThrottlingBehavior();

    throttle.MaxConcurrentCalls = _SymphonyHostProp.MaxConcurrentCalls;     // 200;         // default 16       // 64
    throttle.MaxConcurrentInstances = _SymphonyHostProp.MaxConcurrentInstances; // 1000;     // default 26       // 464
    throttle.MaxConcurrentSessions = _SymphonyHostProp.MaxConcurrentCalls;      // default 10       // 400

    host.Description.Behaviors.Add(throttle);
}

// open the host - bring it into life!
host.Open();

我有客户端使用这样的 nettcpbinding 连接到该主机

int MaxBuffer = 64;     // 64 Mb
int bufferSize = MaxBuffer * 1024 * 1024;   // 67108864               

// -----------------------------------------
// binding for normal clients (default) 
// -----------------------------------------
_tcpBinding = new NetTcpBinding(SecurityMode.None, true);
_tcpBinding.MaxBufferPoolSize = bufferSize; // 64 Mb
_tcpBinding.MaxBufferSize = bufferSize;
_tcpBinding.MaxReceivedMessageSize = bufferSize;
_tcpBinding.TransferMode = TransferMode.Buffered;
_tcpBinding.ReaderQuotas.MaxArrayLength = bufferSize;
_tcpBinding.ReaderQuotas.MaxBytesPerRead = bufferSize;
_tcpBinding.ReaderQuotas.MaxStringContentLength = bufferSize;
_tcpBinding.MaxConnections = 100;
//_tcpBinding.ReceiveTimeout = new TimeSpan(0, 0, 5);
_tcpBinding.SendTimeout = MyHost.SendTimeout;
_tcpBinding.ReliableSession.Enabled = true;
//tcpBinding.ReliableSession.InactivityTimeout = new TimeSpan(7, 0, 0, 0);    // 7 days

'data' 暴露对象的定义如下：

[ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall,
ConcurrencyMode = ConcurrencyMode.Multiple,
UseSynchronizationContext = false)]  
public class Data : HBase, IData

问题是，在主机正常运行期间，突然连接了大约 50 个用户，IDE 中的输出窗口显示数百个与 wcf 相关的错误。

然后，如果我很幸运，它会在几秒钟后自行消失，但在此期间，整个 UI 和主机应用程序的所有内容都会冻结，WCF 不再为任何其他用户提供服务。然后当它回来时一切都很好，直到它再次开始出错..

这里似乎没有任何内部网络问题。我已经启用了跟踪，但我在其中找不到太多有用的信息。我只是想知道是否有人经历过这种行为？

如果需要，我很乐意提供更多信息！

在我的输出窗口中创建了 1000 个这样的错误。 

A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.dll
4

2 回答 2

2

第一次机会异常不是错误。这些通常是会被捕获的异常。你应该忽略它们。

您应该担心的异常是未被捕获的异常。

于 2011-03-18T20:34:14.143 回答
1

我最近遇到了这个问题。在我的情况下，我使用的是自定义 log4net WCF Appender，并且 log4net 库旨在永远不会抛出未捕获的异常，这就是我A first chance exception在调试窗口中获得的原因。我只需将进行调用的客户端和服务本身包装在 try catch 块中，以便我可以在 log4net 之前拦截异常，这使我能够找到真正的原因。

虽然您的异常似乎源于不同的问题，但解决方案仍然是相同的。获取这些尝试/追赶信息，以便您可以获取完整的错误详细信息并确定问题的根源。

顺便说一句，如果您的整个应用程序崩溃了，您可以使用一个非常方便的技巧来获取导致它崩溃的未捕获异常。只需在应用程序启动后立即调用它，

AppDomain.Current.UnhandledException += (sender, error) => File.AppendAllText("Fatal.log", error.ExceptionObject.ToString() + "\r\n");
于 2012-09-17T07:21:39.087 回答