Cannot understand WCF error message, help needed

Question

I have a simple web service to allow applications to query my CMDB. The function I am having trouble with works with a small resultset but fails with a larger one, indicating that it is something in the WCF service config that is preventing it succeeding.

I have a simple WinForms test app with a Service Reference to the web service and a single function that calls the function in question.

The smaller result set returns ~120KB of xml, the failing larger resultset is ~2MB. I have tried increasing the size of the maxReceivedMessageSize and maxStringContentLength without success.

Is there some config I have missed? I would be expecting a more detailed error message if that was the problem.

Thanks in advance,

Nick

---

The error the is returned is:

System.ServiceModel.CommunicationException: The underlying connection was closed: The connection was closed unexpectedly. --->
System.Net.WebException: The underlying connection was closed: The connection was closed unexpectedly.
   at System.Net.HttpWebRequest.GetResponse()
   at System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout)
   --- End of inner exception stack trace ---

Server stack trace: 
   at System.ServiceModel.Channels.HttpChannelUtilities.ProcessGetResponseWebException(WebException webException, HttpWebRequest request, HttpAbortReason abortReason)
   at System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout)
   at System.ServiceModel.Channels.RequestChannel.Request(Message message, TimeSpan timeout)
   at System.ServiceModel.Channels.ClientReliableChannelBinder`1.RequestClientReliableChannelBinder`1.OnRequest(TRequestChannel channel, Message message, TimeSpan timeout, MaskingMode maskingMode)
   at System.ServiceModel.Channels.ClientReliableChannelBinder`1.Request(Message message, TimeSpan timeout, MaskingMode maskingMode)
   at System.ServiceModel.Channels.ClientReliableChannelBinder`1.Request(Message message, TimeSpan timeout)
   at System.ServiceModel.Security.SecuritySessionClientSettings`1.SecurityRequestSessionChannel.Request(Message message, TimeSpan timeout)
   at System.ServiceModel.Dispatcher.RequestChannelBinder.Request(Message message, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs)
   at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
   at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)

Exception rethrown at [0]: 
   at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
   at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
   at TestRig.CmdbDataService.ICmdbDataService.GetMonitors(String client)
   at TestRig.CmdbDataService.CmdbDataServiceClient.GetMonitors(String client) in C:\Documents and Settings\nfoster\My Documents\Visual Studio Projects\Virtual Operations Manuals\Trunk\src\TestRig\Service References\CmdbDataService\Reference.vb:line 1480
   at TestRig.Form1.btnGetServers_Click(Object sender, EventArgs e) in C:\Apps\Virtual Operations Manuals\Trunk\src\TestRig\Form1.vb:line 8

The calling function in the application is:

Private Sub btnGetMonitors_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGetMonitors.Click
  txtResults.Text = String.Empty
  Dim proxy As CmdbDataService.CmdbDataServiceClient = Nothing
  Try
    proxy = New CmdbDataService.CmdbDataServiceClient("WSHttpBinding_ICmdbDataService")
    Dim monitors As TestRig.CmdbDataService.ConfigurationItems = proxy.GetMonitors(txtClientName.Text)
    proxy.Close()
    For Each monitor In monitors
      txtResults.Text &= monitor.Name & " (" & monitor.TypeName & ")" & vbCrLf
    Next
    txtResults.Text &= monitors.Count & " monitors returned"
  Catch ex As Exception
    If Not IsNothing(proxy) AndAlso proxy.State <> ServiceModel.CommunicationState.Closed Then proxy.Abort()
    txtResults.Text = ex.ToString
  Finally
    proxy = Nothing
  End Try
End Sub

On the test rig side the app.config contains the following serviceModel:

  <system.serviceModel>
    <diagnostics>
      <messageLogging logMalformedMessages="true" logMessagesAtServiceLevel="true"
        logMessagesAtTransportLevel="true" />
    </diagnostics>
    <behaviors />
    <bindings>
      <wsHttpBinding>
        <binding name="WSHttpBinding_Default" closeTimeout="00:05:00"
          openTimeout="00:05:00" receiveTimeout="00:10:00" sendTimeout="00:05:00"
          maxBufferPoolSize="104857600" maxReceivedMessageSize="104857600">
          <readerQuotas maxDepth="104857600" maxStringContentLength="104857600"
            maxArrayLength="104857600" maxBytesPerRead="104857600" maxNameTableCharCount="104857600" />
        </binding>
      </wsHttpBinding>
    </bindings>
    <client>
      <endpoint address="http://localhost/CmdbServices/DataService.svc/soap12"
        binding="wsHttpBinding" bindingConfiguration="WSHttpBinding_Default"
        contract="CmdbDataService.ICmdbDataService" name="WSHttpBinding_ICmdbDataService">
        <identity>
          <userPrincipalName value="MyMachine\ASPNET" />
        </identity>
      </endpoint>
    </client>
  </system.serviceModel>

and on the service side the web.config is:

  <system.serviceModel>
    <diagnostics performanceCounters="Default">
      <messageLogging logMalformedMessages="true" logMessagesAtServiceLevel="true"
       logMessagesAtTransportLevel="true" />
    </diagnostics>
    <services>
      <service behaviorConfiguration="ServiceBehavior" name="MyCorp.Cmdb.Services.DataService.CmdbDataService">
        <endpoint address="soap12" binding="wsHttpBinding" contract="MyCorp.Cmdb.Services.DataService.ICmdbDataService" />
        <endpoint address="soap11" binding="basicHttpBinding" contract="MyCorp.Cmdb.Services.DataService.ICmdbDataService" />
        <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" />
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="ServiceBehavior">
          <serviceMetadata httpGetEnabled="true"/>
          <serviceDebug includeExceptionDetailInFaults="true"/>
        </behavior>
      </serviceBehaviors>
    </behaviors>
  </system.serviceModel>

Answer 1

A collegue of mine has just pointed me at this blog post where the actual culprit is the maxItemsInObjectGraph property in the endpoint behaviours.

Bumping these up has solved the problem, I must have just passed over the default threshold of 65536 :D

Nice to see the error messages point you in the right direction :(

Cheers....

Also: You might get this error because one of your web methods are using class that is not a [DataContract] class.

Answer 2

This blog explains how to set up a trace listener and use the svctraceviewer.exe.

http://tbszone.com/post/2010/11/16/WCF-The-connection-was-closed-unexpectedly.aspx