How to trace WCF serialization issues / exceptions

Question

I occasionally run into the problem that an application exception is thrown during the WCF-serialization (after returning a DataContract from my OperationContract). The only (and less meaningfull) message I get is

System.ServiceModel.CommunicationException : The underlying connection was closed: The connection was closed unexpectedly.

without any insight to the inner exception, which makes it really hard to find out what caused the error during serialization.

Does someone know a good way how you can trace, log and debug these exceptions? Or even better can I catch the exception, handle them and send a defined FaulMessage to the client?

thank you

Glaucoma

Answer 1

You should get the inner exception if you configure your service behavior like this:

<system.serviceModel>
     <behaviors>
         <serviceBehaviors>
               <behavior name="YourServiceBehaviour">
                   ...
                   <serviceDebug includeExceptionDetailInFaults="true" />
                   ...
               </behavior>
         </serviceBehaviors>
     </behaviors>
</system.serviceModel>

Additionally you can enable tracing. Did not find a good article now, but maybe this gets you started:

http://developers.de/blogs/damir_dobric/archive/2009/03/24/using-of-wcf-trace.aspx

Bacardi

thanks for your reply. The includeExceptionDetailInFaults attribute only applies for exceptions that occur inside your OperationContract boundaries. issues during serialization occur outside these boundaries. Your second proposal might be a solution to log (but not handle) these issues. I will take a deeper look it. – Glaucoma

Many thanks for the link. Logging helped me to find the problem. – Aspirator

Answer 2

I had that problem, and it was a serialization issue... sometimes I was sending a DataTable without any column, in that case the channel just closed without any error or trace.

Gargoyle