Mariadb service is not running. Can't connect to MySQL server

When I visit my site . I got this error:

Then I try to migrate my site this command: bench migrate. I get this warning:

How to solve this…

Note: This site is already in production. I got the same error from all of my sites that are on this bench.


I got the solution. My MariaDB status failed. I ran service mariadb restart and solve this problem.