当 UserNamePasswordValidator 处理时间过长时，WCF ServiceHost 崩溃

Question

我发现了一种情况，如果 WCF ServiceHost 具有需要一段时间来处理的 UserNamePasswordValidator，WCF 客户端可能会导致 WCF ServiceHost 崩溃。在我向微软提出这个问题之前，我想听听有关解决方案的任何建议。

重现的步骤是：

1. 打开一个频道
2. 调用需要 10 秒返回的 API 方法。
3. 在 API 方法返回之前关闭通道。
4. API 方法返回。 ServiceHost 崩溃。

仅当 UserNamePasswordValidator 需要一段时间来处理（我的示例，2 秒睡眠）时才会发生上述情况。如果 UserNamePasswordValidator 立即返回，则上述情况发生变化：

1. 打开一个频道
2. 调用需要 10 秒返回的 API 方法。
3. 在 API 方法返回之前关闭通道。
4. 关闭通道等待挂起的 API 方法调用。
5. API 方法返回。
6. 频道已关闭。一切都很好。

客户端代码如下：

public static void Main(string[] args)
{
    var binding = new NetTcpBinding(SecurityMode.TransportWithMessageCredential);
    binding.Security.Message.ClientCredentialType = MessageCredentialType.UserName;
    var identity = new DnsEndpointIdentity("Dummy");
    var endpointAddress = new EndpointAddress(new Uri("net.tcp://localhost:5000/"), identity);
    var channelFactory = new ChannelFactory<IService>(binding, endpointAddress);

    channelFactory.Credentials.ServiceCertificate.Authentication.CertificateValidationMode = X509CertificateValidationMode.None;
    channelFactory.Credentials.UserName.UserName = "foo";
    channelFactory.Credentials.UserName.Password = "bar";

    channelFactory.Open();

    IService service = channelFactory.CreateChannel();

    ThreadPool.QueueUserWorkItem(CallPingOnChannel, service);

    Thread.Sleep(TimeSpan.FromSeconds(1));

    channelFactory.Close();
}

private static void CallPingOnChannel(object state)
{
    var result = ((state) as IService).Ping();
}

ServiceHost设置如下：

public static void Main(string[] args)
{
    var serviceHost = new ServiceHost(typeof(Service), TcpBaseAddress);
    serviceHost.Description.Behaviors.Add(new ErrorHandler());
    var netTcpBinding = new NetTcpBinding(SecurityMode.TransportWithMessageCredential);
    netTcpBinding.Security.Transport.ClientCredentialType = TcpClientCredentialType.Certificate;
    netTcpBinding.Security.Message.ClientCredentialType = MessageCredentialType.UserName;

    serviceHost.Credentials.UserNameAuthentication.UserNamePasswordValidationMode = UserNamePasswordValidationMode.Custom;
    serviceHost.Credentials.UserNameAuthentication.CustomUserNamePasswordValidator = new UserValidator();

    serviceHost.Credentials.ClientCertificate.Authentication.CertificateValidationMode = X509CertificateValidationMode.None;
    serviceHost.Credentials.ServiceCertificate.Certificate = GetCertificate();

    serviceHost.AddServiceEndpoint(typeof(IService), netTcpBinding, "");

    serviceHost.Open();

    Console.ReadLine();
}

而UserValidator的实现如下：

public class UserValidator : UserNamePasswordValidator
{
    public override void Validate(string userName, string password)
    {
        Thread.Sleep(TimeSpan.FromSeconds(2));
    }
}

导致主线程崩溃的未处理异常是：

System.ServiceModel.CommunicationException: The socket connection was aborted. This could be caused by an error processing your message or a receive timeout being exceeded by the remote host, or an underlying network resource issue. Local socket timeout was '10675199.02:48:05.4775807'. ---> System.IO.IOException: The read operation failed, see inner exception. ---> System.ServiceModel.CommunicationException: The socket connection was aborted. This could be caused by an error processing your message or a receive timeout being exceeded by the remote host, or an underlying network resource issue. Local socket timeout was '10675199.02:48:05.4775807'. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host

Answer 1

回答我自己的问题；我向 Microsoft 报告了此问题，他们已确认这是框架中的错误，将在即将发布的版本中修复。

链接：http://connect.microsoft.com/wcf/feedback/details/622164/wcf-servicehost-crashes-when-usernamepasswordvalidator-takes-too-long-to-process

Answer 2

首先，您应该在客户端代码中捕获 System.TimeOutException。

接下来，您应该考虑扩展您的客户端和服务的 SendTimeout 和 RecieveTimeout。

看看这两个链接。

SendTimeOut Property

RecieveTimeOut Property