c# - 如何解决 WCF 中的 System.ServiceModel.ServerTooBusyException？

Question

我正在开发一个平均每天有 50,000 次访问(大约 140,000 次页面浏览)的网站。 我使用 WCF 作为我的服务 InstanceContextMode = InstanceContextMode.PerCall
另外，我正在使用异步方法调用 WCF 服务，
最近我在某些页面和某些请求上收到以下异常消息:

Exception Type: System.ServiceModel.ServerTooBusyException
Exception Message: The HTTP service located at http://localhost:8090/SmartService.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.
Stack Trace:    at System.Runtime.AsyncResult.End[TAsyncResult](IAsyncResult result)
   at System.ServiceModel.Channels.ServiceChannel.SendAsyncResult.End(SendAsyncResult result)
   at System.ServiceModel.Channels.ServiceChannel.EndCall(String action, Object[] outs, IAsyncResult result)
   at System.ServiceModel.Channels.ServiceChannelProxy.TaskCreator.<>c__DisplayClass5`1.<CreateGenericTask>b__4(IAsyncResult asyncResult)
   at System.Threading.Tasks.TaskFactory`1.FromAsyncCoreLogic(IAsyncResult iar, Func`2 endFunction, Action`1 endAction, Task`1 promise, Boolean requiresSynchronization)
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Smartiz.ClientServices.ContentService.<GetContentsByIdsAsync>d__18.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at Smartiz.UI.Controllers.CompareController.<FillRequiredFields>d__36.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Smartiz.UI.Controllers.CompareController.<GetDevices>d__4b.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at Smartiz.UI.Controllers.CompareController.<Index>d__73.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Web.Mvc.Async.TaskAsyncActionDescriptor.EndExecute(IAsyncResult asyncResult)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass37.<BeginInvokeAsynchronousActionMethod>b__36(IAsyncResult asyncResult)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3d()
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f()
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f()
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f()
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f()
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass33.<BeginInvokeActionMethodWithFilters>b__32(IAsyncResult asyncResult)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass21.<>c__DisplayClass2b.<BeginInvokeAction>b__1c()
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass21.<BeginInvokeAction>b__1e(IAsyncResult asyncResult)
   at System.Web.Mvc.Controller.<BeginExecuteCore>b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState)
   at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult)
   at System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult)
   at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult)
   at System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__5(IAsyncResult asyncResult, ProcessRequestState innerState)
   at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult)
   at System.Web.HttpApplication.CallHandlerExecutionStep.OnAsyncHandlerCompletion(IAsyncResult ar)

        =========== Inner Exception ===========
        Exception Type: System.Net.WebException
        Exception Message: The remote server returned an error: (503) Server Unavailable.

可以将serviceBehaviors改成下面这样吗？
以下是一个好的解决方案吗？

  <system.serviceModel>
    <services>
      <service name="Smartiz.WcfService.SmartService" behaviorConfiguration="ServiceBehavior">
        <host>
          <baseAddresses>
            <add baseAddress="http://localhost/" />
          </baseAddresses>
        </host>
        <endpoint address="" binding="basicHttpBinding" contract="Smartiz.WcfService.ISmartService" bindingConfiguration="basicHttpBinding">
          <identity>
            <dns value="localhost" />
          </identity>
        </endpoint>
        <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" />
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="ServiceBehavior">
          <serviceThrottling maxConcurrentCalls="2147483647" maxConcurrentInstances="2147483647" maxConcurrentSessions="2147483647" />
          <serviceMetadata httpGetEnabled="true" httpsGetEnabled="true" />
          <dataContractSerializer maxItemsInObjectGraph="2147483647" />
          <serviceDebug includeExceptionDetailInFaults="true" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <protocolMapping>
      <add scheme="https" binding="basicHttpsBinding" />
      <add scheme="http" binding="basicHttpBinding" />
    </protocolMapping>
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true" minFreeMemoryPercentageToActivateService="0" />
    <bindings>
      <basicHttpBinding>
        <binding name="basicHttpBinding" maxReceivedMessageSize="2147483647" messageEncoding="Text" textEncoding="utf-8" maxBufferPoolSize="2147483647">
          <readerQuotas maxDepth="2147483647" maxStringContentLength="2147483647" maxArrayLength="2147483647" maxBytesPerRead="2147483647" maxNameTableCharCount="2147483647" />
          <security mode="None">
          </security>
        </binding>
      </basicHttpBinding>
    </bindings>
  </system.serviceModel>

我的意思是 serviceThrottling maxConcurrentCalls="2147483647"maxConcurrentInstances="2147483647"maxConcurrentSessions="2147483647"

Answer 1

首先检查应用程序池是否正常。 如果您的应用程序在一段时间内产生太多异常，您将收到相同的错误消息。

根据我的经验，如果相关属性 maxConcurrentInstances 和 maxConcurrentSessions 像这里一样正确设置 - 发生此错误时 web.config 中有问题。