IIS Server Error (loop?) after app pool recycleRSS

1 reply

Last post Dec 13, 2019 03:13 AM by Yuk Ding

  • IIS Server Error (loop?) after app pool recycle

    Dec 12, 2019 03:09 PM|tobybrown|LINK

    Hi all,

    Ran an upgrade on a live system today, the software is an ASP.NET MVC app that gets placed into a staging directory and then the directories are switched and the app pool is recycled.

    After the upgrade was complete, trying to access the app via a browser caused the user to receive an ERR_TOO_MANY_REDIRECTS response.

    In the logging database, the message thrown by IIS was as follows: 

    The configuration file has been changed by another program. (D:\Prod\UI\App\web.config)

    The above error was logged in the database roughly 10 times per second.

    Luckily we have two web nodes and the load balancer sent the users to the working web-server.

    The way we fixed this issue was: rather than recycle the app pool, stop the app pool and start it again, manually.

    So we all have a few questions:

    • What causes this issue?
    • Why did it only happen on one node, as well as never happening on any other systems that we have running the same software?
    • What can we do to ensure this doesn't happen again? (other than stopping the app pool and starting it again manually if possible)
  • Re: IIS Server Error (loop?) after app pool recycle

    Dec 13, 2019 03:13 AM|Yuk Ding|LINK

    Hi tobybrown,

    I think it is hard to answer your question by only reviewing your description.  Based on my understanding, IIS will return TOO_MUCH_REDIRECT only when the request get into a redirect loop to himself.

    So you have to monitor these request with either web browser development  tool or fiddler. You need to check why these request get redirected over and over again.  In some case, SSO session get expired could cause this issue.

    Anyway, please  check request logs and provide more detail information.

    Best Regards,

    Jokies Ding

    Yuk Ding

    MSDN Community Support
    Please remember to "Mark as Answer" the responses that resolved your issue.