I am having the same issue as described in this post, Diagnosing "Request timed out" HttpExceptions. I've turned on Failed Request Tracing as recommended and am working with someone at MS (although it's painfully slow).
The original post hasn't been updated in over a year, so I'm wondering if a fix was ever found or if you're just ignoring these errors.
Any help would be appreciated.
After over seven months of troubleshooting this issue, the fine folks at Microsoft finally tracked down the problem. It didn't end up being that complicated an issue, we all certainly learned a lot about IIS 7+ integrated mode.
In summary:
In IIS6 & IIS7+ Classic mode, the request doesn’t reach asp.net until the entire entity body is read. If the entity body doesn’t get completely read, asp.net has never been reached so http just logs the error and asp.net is never the wiser.
However, in IIS7+ Integrated mode, asp.net picks up the request immediately, so if the entity body doesn’t get completely read, asp.net logs the timeout and triggers the exception.
So, these exceptions can safely be ignored because they are expected behavior.
I really hope this helps someone else out there.
来源：https://stackoverflow.com/questions/4929115/any-progress-on-diagnosing-request-timed-out-httpexceptions