I wrote a post a while ago covering the use of Monit to monitor services running and the use case I covered was to ensure these services restarted on failure. While a useful feature of Monit, it seems to be now a little redundant with SystemD having a built in restart feature. Same use case where MySQL (or MariaDB in this case) is being killed by Apache’s oom killer. I first copied the original systemd file associated with Mariadb from /usr/lib/systemd/system/mariadb.