Question

我们收到此错误：

System.ServiceModel.ServerTooBusyException：要求创建可靠的会议已被RM拒绝目的地。服务器 'net.tcp：// localhost：50000 /'也是忙着处理这个请求。尝试稍后再试。渠道不可能打开。

据我了解，我需要在ReliableSession绑定中增加MaxPendingChannels的值。

但是我们在这样的代码中配置WCF：

serviceHost = new ServiceHost(typeof(MyServiceClass));
ServiceEndpoint endPoint = serviceHost.AddServiceEndpoint(
    typeof(IMyService),
    new NetTcpBinding(SecurityMode.None, true),
    endPointAddress);

那么如何以编程方式设置ReliableSession.MaxPendingChannels？（我可以找到的所有示例都使用配置文件）

在web page上搜索一个选项的MaxPendingChannels，但它似乎过于复杂。

Answer 1

这就是我所做的：

 private Binding CreateBindingWith_MaxPendingChannels_Set(Binding baseBinding)
 {
     BindingElementCollection elements = baseBinding.CreateBindingElements();
     ReliableSessionBindingElement reliableSessionElement = 
                elements.Find<ReliableSessionBindingElement>();
     if (reliableSessionElement != null)
     {
         reliableSessionElement.MaxPendingChannels = 128;

         CustomBinding newBinding = new CustomBinding(elements);

         newBinding.CloseTimeout = baseBinding.CloseTimeout;
         newBinding.OpenTimeout = baseBinding.OpenTimeout;
         newBinding.ReceiveTimeout = baseBinding.ReceiveTimeout;
         newBinding.SendTimeout = baseBinding.SendTimeout;
         newBinding.Name = baseBinding.Name;
         newBinding.Namespace = baseBinding.Namespace;
         return newBinding;
     }
     else
     {
         throw new Exception("the base binding does not " +
                             "have ReliableSessionBindingElement");
     }
 }

.....

 Binding customBinding = CreateBindingWith_MaxPendingChannels_Set(
      new NetTcpBinding(SecurityMode.None, true));

 serviceHost = new ServiceHost(typeof(MyService));
 ServiceEndpoint endPoint = serviceHost.AddServiceEndpoint(
                    typeof(IMyService),
                    customBinding,
                    endPointAddress);

Answer 2

我还需要在代码中设置此属性，在研究之后发现有两种方法可以通过编程方式进行。

第一种方法是直接在代码中创建绑定元素，并按照CustomBinding MSDN

中的描述从它们创建新的自定义绑定

// Create a custom binding that contains two binding elements.
ReliableSessionBindingElement reliableSession = new ReliableSessionBindingElement();
reliableSession.MaxPendingChannels = 100;

TcpTransportBindingElement tcpTransport = new TcpTransportBindingElement();

CustomBinding binding = new CustomBinding(reliableSession, tcpTransport);

我找到的第二种方法是从现有绑定中获取对绑定元素的引用，如How to: Customize a System-Provided Binding所述。这就是最佳答案。

我尝试在NetTcpBinding上设置ReliableSession属性，但实际上并没有修改我期望的MaxPendingConnections属性。在查看NetTcpBinding和ReliableSession的.NET源代码后，我发现在绑定上设置此属性就像这样

NetTcpBinding netTcpBinding = new NetTcpBinding(SecurityMode.None, true);

netTcpBinding.ReliableSession = 
    new OptionalReliableSession(
        new ReliableSessionBindingElement()
            {
                MaxPendingChannels = 100
            });

实际上并未在绑定上设置MaxPendingChannels属性。

我最终直接从绑定元素创建绑定，因为我想精确控制绑定

Answer 3

或者您可以使用ReliableSession中的NetTcpBinding属性的构造函数，如下所示：

// initialize ReliableSessionBindingElement object
var reliableSessionBindingElement = new ReliableSessionBindingElement
{
  MaxPendingChannels = 128
  // set other properties here
}; 

binding.ReliableSession = new ReliableSession(reliableSessionBindingElement)
{
  // set properties here
};

有关详细信息，请参阅：http://msdn.microsoft.com/en-us/library/ms585454(v=vs.110).aspx

Answer 4

如果使用NetTcpRelayBinding之类的中继绑定，则可以使用以下代码：

public static class NetTcpRelayBindingExtension
{
    public static void SetReliableSessionMaxPendingChannels(this NetTcpRelayBinding baseBinding, Int32 MaxPendingChannels)
    {
        var bindingType = baseBinding.GetType();
        var bindingProperty = bindingType.GetField("session", BindingFlags.GetField | BindingFlags.Instance | BindingFlags.NonPublic);
        var reliableSession = (ReliableSessionBindingElement)bindingProperty.GetValue(baseBinding);
        reliableSession.MaxPendingChannels = MaxPendingChannels;
    }
}

用法：

var binding = new NetTcpRelayBinding();
binding.SetReliableSessionMaxPendingChannels(128);

在代码中创建NetTcpBinding时，如何设置ReliableSession.MaxPendingChannels？

4 个答案: