We have a MySQL-MMM environment with two masters, two slaves, and a monitoring host. We need to perform maintenance on the monitoring host (quick hardware replacement). I know that while the monitoring daemon isn't running, the floating IPs won't automatically move but assuming that the database hosts don't have any problems during the maintenance should I expect any problems taking the monitoring host offline?
Make sure you kill -9 the mmm_mond daemon. That way it won't have a chance to remove the virtual IP's. After you kill the daemon and before you take the monitor offline, make sure you also kill the agents on the db machines, so it doesn't do unexpected things when your monitor boots up next time (or don't if you don't care ;) ). You can verify the machine the VIP is on by running 'ip addr show' on the db hosts.