I am using new relic to monitor the performance of my server. Recently I noticed a very strange problem where for every 3 hours, the server will be down for 1 minute. And in the new relic report, during the server down time, there were sudden spike on the database.
The problem is I am new in system admin, I don't know how to view the database log. I am using Mariadb on a Ubuntu 14.04 machine. So, where can I find the log? I tried to view in /var/log/mysql.err, /var/log/mysql.log and /var/log/mysql/error.log there are no content inside.
I also tried grep 'mysql' /var/log/syslog, nothing found as well.
Do I need to enable the logging in mariadb config file? If so, how?