How to debug iis "Service Unavailable" and (possibly) related w3wp.exe error in event viewer

suddently my website (asp.net-mvc iis) is down with error "Service unavailable". when i go to check the event viewer i see this error:

Source: VsJitDebugger

Error: An unhandled exception ('') occurred in w3wp.exe [5208]. Just-In-Time debugging this exception failed with the following error: Debugger could not be st开发者_JS百科arted because no user is logged on.

i tried starting and stopping the service but didn't seem to fix anything.

Is this an application bug or an enviroment issue? Can someone point me in the right direction on how to debug this. Site works fine locally (of course)

You've already discovered that restarting your box will fix the issue, I thought you might like to know that actually you only needed to restart IIS.

Open your command line in admin mode enter iisreset

and you won't have to restart.

Check your site's web.config file to see if system.web/compilation@debug="true". If your site is in debug mode, try setting that attribute to false and see if the problem is remedied.

I would first check the application code.

The symptoms you describe can result from an application issue.

If you have an app that has an endless loop, IIS will restart the app and resubmit the request, resulting in another endless loop. IIS will eventually shutdown w3wp.exe because of that, and you will get 503 service unavailable.

found stackoverflow exception in my app which caused this issue. had to push out a new version and reboot the box and issue fixed.