IIS 7 and Above
Known Issues and Workarounds
Requests hangs in RequestAcquireState - unable to install hotfix KB28...
Re: Requests hangs in RequestAcquireState - unable to install hotfix...
Feb 17, 2015 10:11 AM|Markus-AD|LINK
we already had .Net 4.5.2 running and the problem also appears there.
We already know what the problem is but Microsoft has to solve it:
When a request is made the session for that request gets locked and should be unlocked by the end of the request.
When it takes too long to process (e.g. longer than 30 seconds) the client may cancel the request to the server.
But the server does not fully cleanup the running request. The EndRequest is not called and therefore the session is still blocked.
More and more retries are waiting and wasting CPU which leads to other blocked sessions and suddenly the whole IIS can't do anymore.
Maybe the only solution is to uninstall everything, install the hotfix and re-install everything.
But that could not be the way. Microsoft should create a new hotfix or service pack (for .NET).
You can test it on your own:
Create an application which locks the session in the beginrequest, than wait and release the session in endrequest.
When open connection are closed by the client the Endrequest is not always called.