Recently I discovered a tool that I had needed for a long time. Fiddler, a freeware product created and supported by Microsoftie Eric Lawson, can be used to debug HTTP traffic from any web browser (or client application). Here's how you can use it:
1. View/Analyze HTTP traffic....
2. Generate test scripts....
If you're dealing with an issue that shows up only in production, sometimes you have to write special diagnostic code. This technique is known as instrumentation. If you don't have a license for a specialized profiler, or if you just want to focus on a small set of critical areas in your code, use the techniques in this post to find your bottleneck(s).