App Service "Always On" Not Working. RRS feed

  • General discussion

  • Hi there,

    Recently i configured "Always On" in one of my .Net Core App Service(Windows). I scale up the app service from B1 to S1. But Always On is not working(I think). Is there any way to confirm that "Always On" feature is working?

    Thursday, April 2, 2020 7:52 AM

All replies

  • Thanks for asking question! Could you please elaborate on what error you are getting to help you better on this? Also try restarting your web app.

    To add to this, By default, web apps are unloaded if they are idle for a set period of time but if you turn on the Always On setting this keeps the app always loaded and eliminates longer load times after the app is idle or even when there's no traffic. Also, you can’t control the endpoint and It always sends a request to the application root. This feature is required for continuous WebJobs or for WebJobs that are triggered using a CRON expression.


    We're migrating from MSDN to Microsoft Q&A as our new forums and Azure App Service has already made the move!  In future, you can ask and look for the discussion for Azure App Service related questions here:   https://docs.microsoft.com/answers/topics/azure-webapps.html

    We are actively working to onboard remaining Azure services on Microsoft Q&A. We will make a public announcement once complete. Want to Learn more about new platform: Microsoft Q&A Getting Started

    Thursday, April 2, 2020 10:07 AM
  • Hi SnehaAgrawal,

    I have turn on Always On setting on the app service but the app still goes idle after some times(when no traffic). I also restart the app service but still same it goes idle. As i know turning Always On setting azure ping the app service every couple of minute but I didn't find any HTTP request after the app service goes idle.

    Thursday, April 2, 2020 12:04 PM
  • Friday, April 3, 2020 2:49 AM
  • Thanks Suwat,

    here is my app service details:

    Subscription GUID: 7c08...b80a

    Site Name: hxr...opi

    I also added tempt.txt file on d:\home\logFiles\ folder.

    Friday, April 3, 2020 8:06 AM
  • AlwaysOn did send a request (User-Agent: AlwaysOn) every 5 mins to w**.h**.com and 200 was returned.   This should keep the app alive.   Describe how you detect the app went idle?   Provide the most recent UTC time it went idle.


    Friday, April 3, 2020 5:28 PM
  • Hi Suwat,

    The recent idle time is 18:04(UTC)-18:58(UTC) 03 April 2020. There is no HTTP request on that time. Here is the http metrics from portal-

    Friday, April 3, 2020 7:01 PM
  • We might have omitted AlwaysOn from metric - since it is synthetic.   The most important thing - did you observe your application terminated (idle) and restart etc?


    Friday, April 3, 2020 7:11 PM
  • Hi Suwatch,

    No, i just look at http metrics. I started tracing application logs. If i found application shutdown i will let you know.

    Thanks for your support.

    Friday, April 3, 2020 7:35 PM