WCF service returns error 500 on /js request

Question

I have a wcf service that randomly begins to fail when requesting the autogenerated javascript that wcf supports making. But I have no luck tracking down why. The js thing is part of the wcf featureset, so I dont know how it can suddenly begin to fail and be unable to work until IIS is recycled.

The http log gives me:

2010-06-10 09:11:49 W3SVC2095255988 myip GET /path/myservice.svc/js _=1276161113900 80 - ip browser 500 0 0

So its an error 500, and that is about the only thing I can figure out. The event log contains no information.

Requests to /path/myservice.svc works just fine. After recycling IIS it works again, and some days later it begins to fail until I recycle IIS.

     <service
        name="path.myservice"
        behaviorConfiguration="b">
        <endpoint
           address=""
           behaviorConfiguration="eb"
           binding="webHttpBinding"
           contract="path.Imyservice" />
     </service>
     ...
     <endpointBehaviors>
        <behavior name="eb">
           <enableWebScript />
        </behavior>
     </endpointBehaviors>
     <serviceBehaviors>
        <behavior name="b">
           <dataContractSerializer maxItemsInObjectGraph="2147483647" />
           <serviceMetadata httpGetEnabled="true" />
           <serviceDebug includeExceptionDetailInFaults="true" />
        </behavior>
     </serviceBehaviors>

I dont see any problems in the web.config settings either.

Any clues how I can track down what the problem is?

Edit:

Just to make it clear - It is the generation of javascript that fails, my code is never invoked. Calls to the service works just fine.

Answer 1

It seems your WCF Service throws an Exception. You can catch this unhandled Exception in the Application_Error method in Global.asax, than write it to a log file.

protected void Application_Error(object sender, EventArgs e)
{
    Exception ex = Server.GetLastError().GetBaseException();
    //TODO: write to log
}

Answer 2

I would recommend you to enable tracing in your service and look at the generated logs with Service Trace Viewer Tool. Trace only errors to keep your logs small.