Error Message Logging using WCF

This topic describes how you can configure message logging for different scenarios.

Windows Communication Foundation (WCF) does not log messages by default. To activate message logging, you must add a trace listener to the System.ServiceModel.MessageLogging trace source and set attributes for the <messagelogging> element in the configuration file.

The following example shows how to enable logging and specify additional options.

<system.diagnostics>
  <sources>
      <source name="System.ServiceModel.MessageLogging">
        <listeners>
                 <add name="messages"
                 type="System.Diagnostics.XmlWriterTraceListener"
                 initializeData="c:\logs\messages.svclog" />
          </listeners>
      </source>
    </sources>
</system.diagnostics>

<system.serviceModel>
  <diagnostics>
    <messageLogging 
         logEntireMessage="true" 
         logMalformedMessages="false"
         logMessagesAtServiceLevel="true" 
         logMessagesAtTransportLevel="false"
         maxMessagesToLog="3000"
         maxSizeOfMessageToLog="2000"/>
  </diagnostics>


</system.serviceModel>

Recommended Settings for a Production Environment

For a production environment, if you are using WCF trace sources, set the switchValue to Warning. If you are using the WCF System.ServiceModel trace source, set the switchValue attribute to Warning and the propagateActivity attribute to true. If you are using a user-defined trace source, set the switchValue attribute to Warning, ActivityTracing. This can be done manually using the SvcConfigEditor.exe If you do not anticipate a hit in performance, you can set the switchValue attribute to Information in all the previously mentioned cases, which generates a fairly large amount of trace data. The following example demonstrates these recommended settings.

<configuration>
 <system.diagnostics>
  <sources>
    <source name="System.ServiceModel"
            switchValue="Warning"
            propagateActivity="true" >
      <listeners>
        <add name="xml"/>
      </listeners>
    </source>
    <source name="myUserTraceSource"
            switchValue="Warning, ActivityTracing">
      <listeners>
        <add name="xml"/>
      </listeners>
    </source>
  </sources>
  <shareListeners>
    <add name="xml"
         type="System.Diagnostics.XmlWriterTraceListener"
               initializeData="C:\logs\Traces.svclog" />
  </sharedListeners>
 </system.diagnostics>

<system.serviceModel>
  <diagnostics wmiProviderEnabled="true">
  </diagnostics>
 </system.serviceModel>
</configuration>

Recommended Settings for Deployment or Debugging

For deployment or debugging environment, choose Information or Verbose, along with ActivityTracing for either a user-defined or System.ServiceModel trace source. To enhance debugging, you should also add an additional trace source (System.ServiceModel.MessageLogging) to the configuration to enable message logging. Notice that the switchValue attribute has no impact on this trace source.

The following example demonstrates the recommended settings, using a shared listener that utilizes the XmlWriterTraceListener.

<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="C:\logs\Traces.svclog" />
  </sharedListeners>
 </system.diagnostics>

 <system.serviceModel>
  <diagnostics wmiProviderEnabled="true">
      <messageLogging 
           logEntireMessage="true" 
           logMalformedMessages="true"
           logMessagesAtServiceLevel="true" 
           logMessagesAtTransportLevel="true"
           maxMessagesToLog="3000" 
       />
  </diagnostics>
 </system.serviceModel>
</configuration>