If you have setup munin-node on a cPanel server it’s possible that your MySQL graphs stop updating at sometime, or don’t even generate from the beginning.

To fix, edit the following file:

/etc/munin/plugin-conf.d/cpanel.conf

And make sure that the mysql section contains the following:

[mysql*]
user root
group wheel
env.mysqladmin /usr/bin/mysqladmin
env.mysqlopts --defaults-extra-file=/root/.my.cnf