Question

I have a WCF web service called by an ASP .Net web site. In my web method I deliberately don’t catch exceptions, as I want them to be handled by the client web site. The web service is purely an internal application, and I want it to behave like a standard library which expects the caller to handle exceptions. I have includeExceptionDetailInFaults=”true” in the service web.config. When my service throws an exception I get this error:

Log Name:      Application
Source:        ASP.NET 2.0.50727.0
Date:          24/05/2012 09:13:52
Event ID:      1334
Task Category: None
Level:         Error
Keywords:      Classic
User:          N/A
Description:
An unhandled exception occurred and the process was terminated.

Application ID: DefaultDomain

Process ID: 2628

Exception: System.Runtime.Serialization.SerializationException

Message: Type 'System.ServiceModel.ExceptionDetail' in Assembly 'System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' is not marked as serializable.

StackTrace:    at System.Runtime.Serialization.FormatterServices.InternalGetSerializableMembers(RuntimeType type)
   at System.Runtime.Serialization.FormatterServices.GetSerializableMembers(Type type, StreamingContext context)
   at System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.InitMemberInfo()
   at System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.InitSerialize(Object obj, ISurrogateSelector surrogateSelector, StreamingContext context, SerObjectInfoInit serObjectInfoInit, IFormatterConverter converter, ObjectWriter objectWriter)
   at System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.Serialize(Object obj, ISurrogateSelector surrogateSelector, StreamingContext context, SerObjectInfoInit serObjectInfoInit, IFormatterConverter converter, ObjectWriter objectWriter)
   at System.Runtime.Serialization.Formatters.Binary.ObjectWriter.Write(WriteObjectInfo objectInfo, NameInfo memberNameInfo, NameInfo typeNameInfo)
   at System.Runtime.Serialization.Formatters.Binary.ObjectWriter.Serialize(Object graph, Header[] inHeaders, __BinaryWriter serWriter, Boolean fCheck)
   at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Serialize(Stream serializationStream, Object graph, Header[] headers, Boolean fCheck)
   at System.Runtime.Remoting.Channels.CrossAppDomainSerializer.SerializeObject(Object obj, MemoryStream stm)
   at System.AppDomain.Serialize(Object o)
   at System.AppDomain.MarshalObject(Object o)

How to fix this so my client is able to catch exceptions thrown by the service?

Answer 1

I found the cause of the problem – the exception was being thrown in a worker thread (System.Threading.ThreadPool.QueueUserWorkItem) within my web service, so of course was not being handled. Fixed by adding an exception handler and logging to the worker thread.