When I measure request times on ‘the inside’ of an Asp.Net application and compare it to timings on ‘the outside’ of the app, I get different values — 1000-5000ms strange overheads from time to time.
Maybe the requests are beeing queued up in front of IIS?
Or something strange is going on in an HttpModule?
The question: Is there a way to inspect the request pipeline for tracing exactly where the time is spent before the app is hit?
You can create your own module and register it on top to trace every request with more accuracy, but the measure will start once the IIS delegates the request to the ASP.NET ISAPI module. To get more accuracy you can go to IIS logs.