App service deployed on azure HA environment continuously giving errors with code 400 and 404

Question

We have deployed an app service in azure HA env, we are seeing many errors every 5 min for app host and healthcheck URL giving 400 and 404 error.
There is no error stack available for this in application logs.
I have also turned off 'Always On' feature.
What will be hitting host URL and health check URL continuously? How to prevent these errors?

Answer 1

Thanks for asking question! App Service Always On also generate periodic (every 5min) probes to app instances and causing failed requests with error 404, and this can be found in Application Insights. You may try rewriting the Always on path by referring this blog: 404 response code caused by App Services– AlwaysOn feature might be helpful.

Let us know in case issue persists.

Answer 2

@SnehaAgrawal-MSFT
Thank you for your response. I have turned off 'Always On' option but still I see many errors with 404 or 400 error code for host and health check url. How should I prevent or handle this?