WCF timeout exception detailed investigation

Question

We have an application that has a WCF service (*.svc) running on IIS7 and various clients querying the service. The server is running Win 2008 Server. The clients are runnin

Answer 1

I'm having a very similar problem. In the past, this has been related to serialization problems. If you are still having this problem, can you verify that you can correctly serialize the objects you are returning. Specifically, if you are using Linq-To-Sql objects that have relationships, there are known serialization problems if you put a back reference on a child object to the parent object and mark that back reference as a DataMember.

You can verify serialization by writing a console app that serializes and deserializes your objects using the DataContractSerializer on the server side and whatever serialization methods your client uses. For example, in our current application, we have both WPF and Compact Framework clients. I wrote a console app to verify that I can serialize using a DataContractSerializer and deserialize using an XmlDesserializer. You might try that.

Also, if you are returning Linq-To-Sql objects that have child collections, you might try to ensure that you have eagerly loaded them on the server side. Sometimes, because of lazy loading, the objects being returned are not populated and may cause the behavior you are seeing where the request is sent to the service method multiple times.

If you have solved this problem, I'd love to hear how because I'm stuck with it too. I have verified that my issue is not serialization so I'm at a loss.

UPDATE: I'm not sure if it will help you any but the Service Trace Viewer Tool just solved my problem after 5 days of very similar experience to yours. By setting up tracing and then looking at the raw XML, I found the exceptions that were causing my serialization problems. It was related to Linq-to-SQL objects that occasionally had more child objects than could be successfully serialized. Adding the following to your web.config file should enable tracing:

The resulting file can be opened with the Service Trace Viewer Tool or just in IE to examine the results.