WCF Web 服务太忙

Question

我遇到了繁忙的 wcf 服务问题，客户端可以通过该服务连接并使用它。 下面是关于类的服务器配置和属性的错误和堆栈跟踪。

错误信息和堆栈跟踪：

The HTTP service located at https://my.web.service.com/Service/Service.svc is unavailable.  This could be because the service is too busy or because no endpoint was found listening at the specified address. Please ensure that the address is correct and try accessing the service again later.ExST: 
Server stack trace: 
   at System.ServiceModel.Channels.HttpChannelUtilities.ProcessGetResponseWebException(WebException webException, HttpWebRequest request, HttpAbortReason abortReason)
   at System.ServiceModel.Channels.HttpChannelFactory`1.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout)
   at System.ServiceModel.Channels.RequestChannel.Request(Message message, TimeSpan timeout)
   at System.ServiceModel.Channels.SecurityChannelFactory`1.SecurityRequestChannel.Request(Message message, TimeSpan timeout)
   at System.ServiceModel.Security.SecuritySessionSecurityTokenProvider.DoOperation(SecuritySessionOperation operation, EndpointAddress target, Uri via, SecurityToken currentToken, TimeSpan timeout)
   at System.ServiceModel.Security.SecuritySessionSecurityTokenProvider.GetTokenCore(TimeSpan timeout)
   at System.IdentityModel.Selectors.SecurityTokenProvider.GetToken(TimeSpan timeout)
   at System.ServiceModel.Security.SecuritySessionClientSettings`1.ClientSecuritySessionChannel.OnOpen(TimeSpan timeout)
   at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.OnOpen(TimeSpan timeout)
   at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.CallOpenOnce.System.ServiceModel.Channels.ServiceChannel.ICallOnce.Call(ServiceChannel channel, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.CallOnceManager.CallOnce(TimeSpan timeout, CallOnceManager cascade)
   at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
   at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)

网络服务器配置：

<?xml version="1.0"?>
<configuration>
  <configSections>
    <sectionGroup name="applicationSettings" type="System.Configuration.ApplicationSettingsGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
      <section name="Server.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false"/>
      <section name="ServerEdi.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false"/>
    </sectionGroup>
  </configSections>

  <system.web>
    <httpRuntime maxRequestLength="65536"/>
    <customErrors mode="Off"/>
    <compilation targetFramework="4.5"/>
    <pages controlRenderingCompatibilityVersion="4.0"/>
  </system.web>

  <system.serviceModel>

    <bindings>
      <wsHttpBinding>
        <binding name="IWebService" closeTimeout="01:00:00" openTimeout="01:00:00" receiveTimeout="01:00:00" sendTimeout="01:00:00" allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard" maxBufferPoolSize="2147483647" maxReceivedMessageSize="2147483647" messageEncoding="Text" textEncoding="utf-8" useDefaultWebProxy="true">
          <readerQuotas maxDepth="2147483647" maxStringContentLength="2147483647" maxArrayLength="2147483647" maxBytesPerRead="2147483647" maxNameTableCharCount="2147483647"/>
          <security mode="TransportWithMessageCredential">
            <transport clientCredentialType="None" proxyCredentialType="None" realm=""/>
            <message clientCredentialType="UserName" negotiateServiceCredential="true"/>
          </security>
        </binding>
      </wsHttpBinding>
    </bindings>

    <services>
      <service behaviorConfiguration="nowa" name="ServiceWeb.WebService">
        <endpoint address="" binding="wsHttpBinding" bindingConfiguration="IWebService"
          contract="ServiceWeb.IWebService" />
      </service>
    </services>

    <behaviors>
      <serviceBehaviors>
        <behavior name="nowa">
          <serviceMetadata httpsGetEnabled="true"/>
          <serviceCredentials>
            <serviceCertificate findValue="xxxyyyzzz.com" storeLocation="LocalMachine" x509FindType="FindBySubjectName"/>
            <userNameAuthentication userNamePasswordValidationMode="Custom" customUserNamePasswordValidatorType="ServiceWeb.MyCustomUserNamePasswordValidator,ServiceWeb"/>
            <windowsAuthentication includeWindowsGroups="false" allowAnonymousLogons="false"/>
          </serviceCredentials>
          <serviceAuthorization impersonateCallerForAllOperations="false"/>
          <dataContractSerializer maxItemsInObjectGraph="2147483647"/>
          <serviceDebug includeExceptionDetailInFaults="true"/>
          <serviceThrottling maxConcurrentCalls="500" maxConcurrentInstances="500" maxConcurrentSessions="500" />

        </behavior>

      </serviceBehaviors>
    </behaviors>
    <serviceHostingEnvironment multipleSiteBindingsEnabled="true"/>
  </system.serviceModel>

  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
  </startup>

  <system.webServer>
    <urlCompression doStaticCompression="false"/>
  </system.webServer>

</configuration>   

类属性：

[ServiceBehavior(InstanceContextMode = InstanceContextMode.Single)]
   //[ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall, ConcurrencyMode = ConcurrencyMode.Single)]
  //  [ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall,
   //              ConcurrencyMode = ConcurrencyMode.Multiple)]
    public class WebService : IWebService {}

如果有人可以提供帮助，我将不胜感激 stackoverflow 上描述的案例不完全适合并解决我的案例。目前，该服务正在使用大约 50 个客户。当我调用一个返回一些东西的方法并且你不能异步调用它时，问题就来了，因为答案必须立即传递。

Answer 1

WCF 有一些默认限制值，因此您可能会遇到这些值，请参阅：http://blogs.msdn.com/b/wenlong/archive/2009/07/26/wcf-4-higher-default-throttling-settings-for-wcf-services.aspx

通常，当客户端不关闭连接时，您会收到此错误，连接会一直打开直到超时，阻止任何新调用。