I have recently been experiencing weird behaviour in my development environment when running ASP.Net websites locally on my Windows 8 development computer via IIS8. I have observed the behaviour on two separate websites (one is an old, bloated ASP.Net website with thousands of lines of code and a lot of bad-practice; the other is a new, light-weight ASP.Net MVC with less than 600 lines of code in total and hopefully not so many bad practices).

Both sites are being run through IIS8 locally (i.e. not through Visual Studio's local web server, nor through IIS Express). The problem occurs whether debugging or merely using the sites - regardless of whether VS is open or not.


After serving a small number of requests (perhaps 5 or less), if the app pool isn't refreshed, any future requests will hang indefinitely (until stopped from the browser/client - i.e. I never receive a response and the browser continues waiting). Once this occurs, the only way to get a response is to force stop IIS via the iisreset -stop command. Also, it's client agnostic - I've had the problem happen on Chrome, Firefox, IE, Opera, and via Fiddler.

I'm not really sure how to troubleshoot this - I've looked in Event Viewer and see nothing registered at all, nor does anything obviously wrong show up when I view processes (CPU and RAM usage are completely normal). It doesn't appear to be something wrong in one of the site's codebases.

The problem only began to happen with the second site a couple of days ago - though I can't recall making any changes which could have caused it to occur.


I guess it's a bit hopeful to expect an answer to this one, but: Is there anything obvious which exhibits these symptoms - and, if so, what can be done to fix it?

Failing that, what diagnostic tools are likely to help me identify the cause? I'm not particularly knowledgeable about the internal workings of IIS and don't really know where to look (though, I certainly have tried putting my Google skills to use, I promise!).

Thanks in advance for any who take the time to help with this! I'm happy to provide further details on request.

  • Just FYI, running IIS on a client machine for dev purposes may fall explicitly outside of the scope of ServerFault. – phoebus May 7 '13 at 20:39
  • Yeah, I was wondering about that - but it seemed more appropriate than Stackoverflow to me and I'm not sure where else I should ask it. The setup is designed to mimic our production environment as close as possible (short of actually working on Windows Server) and this seems to be more a problem with the workings of IIS/Windows than with anything specifically related to development. – Zac May 7 '13 at 20:43
  • Very interested to see if you get any answers. I am experiencing a very similar behavior on a 2012 windows server environment hosted at rackspace on a much larger scale. serverfault.com/questions/605612/apppools-hang-in-iis8 ----- Then i saw this was asked a year ago :( – jackncoke Jun 16 '14 at 23:50
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    @jackncoke Sorry I didn't get back to you earlier - I've been on holiday for a few weeks with no computer. Unfortunately, I can't help you with your problem either (if you haven't already resolved it) as my situation was eventually resolved with a new computer. I can only imagine that I'd manage to change some setting(s) in the system which I shouldn't have or installed something that interfered at a low-level... – Zac Jun 25 '14 at 19:50
  • @Zac Thank you for following up with me. I was able to resolve it through a setting in my configuration file. <modules runAllManagedModulesForAllRequests="false"> – jackncoke Jul 9 '14 at 16:38

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