I had the same problem. I just need to run
sudo service mysql start
it happen to me and worked on it for 15 mins and then I wanted to kick myself in the butt once I figure I need to start mysql. Sometimes it doesn’t always start. :)

While this is an old question I though it might be good to answer for someone else who is having the same issue. For me it was a matter of /var/lib/mysql/tc.log growing rapidly in size. After removing the tc.log mariadb started working again.

@Tarrioin

One of the most common issues I’ve ran in to is the systemd or init script is passing a different path than is defined in your my.cnf file for the socket, thus when you attempt to start or restart MySQL, it fails.

So the best thing to do would be to check my.cnf and the associated configuration files to see what is being defined for the socket. If your MySQL configuration is defining something other than what the startup script is asking for, change socket= to /var/run/mysqld/mysqld.sock, save + exit, and then try to restart MySQL/MariaDB again.

Otherwise, you could do the reverse. Check the startup script and change the path of the socket to match that of what’s defined in your MySQL configuration.