WCF超时错误，代码运行正常

Question

I have a project that uses a WCF service to do some database queries, builds an "Environment" object (which consists of different database class objects) and returns it inside a "Workspace" object to the client. It's been running fine.

I added another "Database" type to the service with all the correct contract and method updates. Now when I call the method the client times out after 1 minute. In debugging it take about 3-5 seconds to hit the end of the service method. Then nothing happens for the rest of the minute until on the client side we see a timeout problem. There are no errors/exceptions thrown.

Please see below:

Calling from client:

490  m_ScanWorkspace = m_Connection.ScanProxy.CreateEnvironments

End of service method:

477   return tWorkspace;
478 }

It takes 3-5 seconds to get to line 478 in the service. F10 shows it's complete.

Nothing happens until 1 minute later when line 490 in the client shows a timeout error. while debugging I can see a valid object in tWorkspace.

Answer 1

Firstly, set up WCF tracing using the Diagnostics namespace. Just use the first example on that tutorial and WCF will dump out a log of all activity, which you can open up in the log viewer. It will tell you exactly where the call is failing, which will help you pinpoint the problem.

WCF is great, but the error messages it gives are cryptic and often close to useless. A timeout after 1 minute doesn't necessarily mean what a timeout would normally mean - ie couldn't find the server. It could be other issues.

More than likely there will be a threshold exceeded which causes the response object to be incomplete. This could be array length, string content length, message size, and so on. You will find some of these detailed here: https://stackoverflow.com/a/480191/146077

Good luck!