When hosting had a problem with mssql or a network related problem occured between db and iis, umbraco throws boot failed error. When the connection restores, "boot failed" condition still there until we restart the website from iis. We faced this in all versions of Umbraco. Any suggestion?

tried checking the logs?

We saw network related connection problem from logs

The application doesn't attempt a full reboot unless you... reboot the application. So I believe it will require a restart of the application from IIS when this error occurs. I'm not sure that there are ways around it...

This has annoyed us many times. Using Azure Web Apps and App Environment Variables makes it less of a problem, since the app restarts when modifying the variable, and the database boot issue is usually because of a connection string that needs changing. I don't know of any way to get around it.