Why does mariadb - database server stop?

Question

MySQL

Over the past month, the mariadb - database server process has already stopped twice on the server, because of which sites stopped working - mysql error.

Whether prompt it is possible to understand the reason of shutdown of mariadb somehow??

Answer 1

logs
usually have no place
less often - something crashes or clamps like a container

Answer 2

Most likely, as they said in the comments, there is not enough RAM. You can check by looking in /var/log/messages (or syslog) - if processes are killed, then we will see an out of memory killer there.
What to do? - if this is a commercial site, I would at least increase the server, and even better - separate Nginx and MySQL.
For the advanced - turn on MySQL slow query log and tune - the graph shows that there was a CPU load spike.