.NET Production Debugging

Question

I've had a Windows app in production for a while now, and have it set up to send us error reports when it throws exceptions. Most of these are fairly descriptive and help me find the problem very quickly (I use the MS Application Exception Block).

On a few occasions I have reports that are issues that I can't reproduce, and seem to only happen on a few client machines.

I don't have physical access to these client machines, what are some strategies I can use for debugging? Would it be better to build some tracing into the code, or are there some other alternatives?

Thank you.

Edit: I should have been more clear: The error reports that I get do have the stack trace, but since it's production code, it doesn't indicate the exact line that caused the exception, just the method in which it was thrown.

Answer 1

One option is to generate a (mini-)dump file as close to the point where the exception is thrown as possible. This article talks about how to do this from managed code.

You could then load the dump file into Visual Studio or WinDbg and examine it with the aid of SOS

Answer 2

You are on the right track. You need to create a tracking module which logs actions/exceptions locally.

You can then have a button or a menu option that the user can click to either automatically email you this information the moment the issue occurs, or they can have the option to get hold of the file so that they can transfer it to you in any other way.

You can even build-in a diagnostics code to run an integrity check on the system and sends you a report (maybe it runs all your unit tests to see if they work on that system).