We have multiple app services on the same service plan. When the underlying VM is switched out for updates the apps sometimes fail to start.

The website will then timeout if you try to access it.

I see this in the eventlog.

Application 'MACHINE/WEBROOT/APPHOST/APP...' with physical root 'D:\home\site\wwwroot\' 
created process with commandline 'D:\home\site\wwwroot\App.exe ' 
but either crashed or did not reponse or did not listen on the given port '20236', 
ErrorCode = '0x800705b4'

We see two problems here.

1. When Azure App Services are switched to a new VM (Computer name just changed in eventlog) they sometimes hang. Only way to recover is to click Stop and Start the App Service in the Azure Portal.

2. When the app fails to start, IIS AspNetCore Module does not recover/retry. Causing the app to stay broken until manually stopped and started.

Extra info

• We are using latest .net core 2.0.
• We have multiple apps per App Service Plan.
• We only see this problem when Azure switches out the machine hosting the app service plan.