Comment résoudre System.ServiceModel.ServerTooBusyException dans WCF?

Question

Je développe un site Web avec une moyenne de 50 000 visites (environ 140 000 pages vues) par jour. J'utilise WCF que mes services avec InstanceContextMode = InstanceContextMode.PerCall
De plus, je suis en utilisant des méthodes async pour appeler les services WCF,
Récemment, j'obtenir les messages d'exception suivants sur certaines pages et sur certaines demandes:

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. 

Est-il correct de changer serviceBehaviors comme suit?
Est-ce que ce qui suit est une bonne solution?

 
    <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> 

Je veux dire serviceThrottling maxConcurrentCalls="2147483647" maxConcurrentInstances="2147483647" maxConcurrentSessions="2147483647"

Answer 1

Vérifiez d'abord si l'App piscine est très bien. Si votre application génère trop d'exceptions au cours d'une période, le même message d'erreur s'affiche.

Dans mon expérience souvent - si les propriétés pertinentes maxConcurrentInstances et maxConcurrentSessions sont correctement définies comme ici - c'est quelque chose de défectueux dans le web.config lorsque cette erreur se produit.