I'm in trouble with watchdog :(
Is there any way to register application into systemd watchdog at runtime?
Does linux watchdog only use for system reset or it can be use for application reset?
Systemd's watchdog can be mainly used for 3 different actions:
example unit file:
[Unit] Description=My Little Daemon Documentation=man:mylittled(8) [Service] ExecStart=/usr/bin/mylittled WatchdogSec=30s Restart=on-failure StartLimitInterval=5min StartLimitBurst=4 StartLimitAction=reboot-force
The example is taken from: http://0pointer.de/blog/projects/watchdog.html, which gives a pretty complete overview of what and how you can use the watchdog service.
The Linux watchdog daemon should be used for system reset jobs, though it can also run a "repair binary" on persistent errors that could be used to fix or restart a process. Generally speaking, to monitor daemon processes and restart them you should use the init/upstart/systemd supported methods as already answered and keep the watchdog operation for the most serious "only a reboot is likely to fix things" situations.