I have a problem with an ASP.NET-Core Webapplication running as an Appservice on Azure. We are experiencing frequent spikes in Response-time due to something blocking a thread-worker (at least thats what we think). We do have a couple of Application-Insights profiler traces of requests that should only (and usually do) take 10ths of milliseconds taking more than a minute to complete. On examination it is always the same problem:
Is there any way to see what the thread that is supposed to be processing the awaited task is currently working/waiting on?
Since this looks like a blocking problem, I suspected some blocking calls in the codebase that block threads that are not using ConfigueAwait(false) and then must wait for the blocking call to complete. I have looked through the code and a lot of traces, but I can't seem to find anything that would explain such horrendous await times. The only things I found were waiting times in Expression-Compilation (EF-Core):
But I somehow doubt this is the issue.
I would however like to know what exactly the thread here is waiting on.
TLDR: I want to find the culprit that blocks the awaited Task from being processed