Nagios and `service restart`
Have you tried turning it off and on again?
This is usually the goto solution for failing/frozen services. Something’s wrong let’s just restart whatever. It gets as absurd as running a restart cronjob every hour or two! Of course restarting helps, but it’s not the best solution. It’s often better to find out what’s wrong to begin with, why the thing that is supposed to work is not working anymore.