How to check if a process has hung/died?

Question

PHP

I don’t even know how to google and what solutions there are.
There are a bunch of identical applications on one machine. How to check if it hung, died, or something else happened? And in case something went wrong, it restarted everything.
in other words: monitoring
Or will you have to write your own?

Answer 1

systemd unit write

in other words: monitoring

This is not monitoring.

Answer 2

At a minimum, you can effectively solve the problem of "died - restarted" through Supervisord: supervisord.org