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WebHost failed to process a request. RRS feed

  • Question

  • Hi everyone,

    At random intervall our IIS hosted wcf service fails. A restart of IIS solves the problem. Does anyone has an idea what causes this or where I should look for the problem? Help would be highly appreciated. Thanks!

    Stacktrace as viewed in Event Viewer, name of service replaced with XXX:

    WebHost failed to process a request.
     Sender Information: System.ServiceModel.ServiceHostingEnvironment+HostingManager/12036987
     Exception: System.ServiceModel.ServiceActivationException: The service 'XXX.svc' cannot be activated due to an exception during compilation.  The exception message is: Object reference not set to an instance of an object.. ---> System.NullReferenceException: Object reference not set to an instance of an object.
       at System.ServiceModel.Description.ServiceEndpoint.Validate(Boolean runOperationValidators, Boolean isForService)
       at System.ServiceModel.Description.DispatcherBuilder.ValidateDescription(ServiceDescription description, ServiceHostBase serviceHost)
       at System.ServiceModel.Description.DispatcherBuilder.InitializeServiceHost(ServiceDescription description, ServiceHostBase serviceHost)
       at System.ServiceModel.ServiceHostBase.InitializeRuntime()
       at System.ServiceModel.ServiceHostBase.OnOpen(TimeSpan timeout)
       at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
       at System.ServiceModel.ServiceHostingEnvironment.HostingManager.ActivateService(String normalizedVirtualPath)
       at System.ServiceModel.ServiceHostingEnvironment.HostingManager.EnsureServiceAvailable(String normalizedVirtualPath)
       --- End of inner exception stack trace ---
       at System.ServiceModel.ServiceHostingEnvironment.HostingManager.EnsureServiceAvailable(String normalizedVirtualPath)
       at System.ServiceModel.ServiceHostingEnvironment.EnsureServiceAvailableFast(String relativeVirtualPath)
     Process Name: w3wp
     Process ID: 10980

    Thursday, March 27, 2014 11:50 AM

Answers

  • Hi,

    As @patawa77 said, it will be better if you can post your project here, then we can test it in my side.

    Also to dignose the real issue, I'd suggest you enable tracing for your service.

    The following configuration taken from MSDN can be applied to enable tracing on your WCF service.

    <configuration>
      <system.diagnostics>
        <sources>
          <source name="System.ServiceModel"
                  switchValue="Information, ActivityTracing"
                  propagateActivity="true" >
            <listeners>
                 <add name="xml"/>
            </listeners>
          </source>
          <source name="System.ServiceModel.MessageLogging">
            <listeners>
                <add name="xml"/>
            </listeners>
          </source>
          <source name="myUserTraceSource"
                  switchValue="Information, ActivityTracing">
            <listeners>
                <add name="xml"/>
            </listeners>
          </source>
        </sources>
        <sharedListeners>
            <add name="xml"
                 type="System.Diagnostics.XmlWriterTraceListener"
                 initializeData="Error.svclog" />
        </sharedListeners>
      </system.diagnostics>
    </configuration>

    Best Regards,
    Amy Peng



    We are trying to better understand customer views on social support experience, so your participation in this interview project would be greatly appreciated if you have time. Thanks for helping make community forums a great place.
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    Friday, March 28, 2014 3:05 AM
    Moderator

All replies

  • We need more information. Could you please provide your interface and service implementation and system.servicemodel configuration. Thanks
    Thursday, March 27, 2014 2:34 PM
  • Hi,

    As @patawa77 said, it will be better if you can post your project here, then we can test it in my side.

    Also to dignose the real issue, I'd suggest you enable tracing for your service.

    The following configuration taken from MSDN can be applied to enable tracing on your WCF service.

    <configuration>
      <system.diagnostics>
        <sources>
          <source name="System.ServiceModel"
                  switchValue="Information, ActivityTracing"
                  propagateActivity="true" >
            <listeners>
                 <add name="xml"/>
            </listeners>
          </source>
          <source name="System.ServiceModel.MessageLogging">
            <listeners>
                <add name="xml"/>
            </listeners>
          </source>
          <source name="myUserTraceSource"
                  switchValue="Information, ActivityTracing">
            <listeners>
                <add name="xml"/>
            </listeners>
          </source>
        </sources>
        <sharedListeners>
            <add name="xml"
                 type="System.Diagnostics.XmlWriterTraceListener"
                 initializeData="Error.svclog" />
        </sharedListeners>
      </system.diagnostics>
    </configuration>

    Best Regards,
    Amy Peng



    We are trying to better understand customer views on social support experience, so your participation in this interview project would be greatly appreciated if you have time. Thanks for helping make community forums a great place.
    Click HERE to participate the survey.

    Friday, March 28, 2014 3:05 AM
    Moderator