Prior to investigating a possible migration to MariaDB/Percona/Other from official MySQL, on several servers, running either MySQL 5.1.x or 5.5.x, I would like to upgrade each to the latest minor release within the respective series, for interim stability reasons. I am led to believe that this will not require any changes/migration/caveats, but simply shutting down the server, replacing the current minor version with the latest minor version of the same series, running mysql_upgrade, then restarting (after backing everything up, of course).
Is this the most logical, time-saving option to improve stability? If yes, other than a thorough backup of the databases, including the 'mysql' database, and running the mysql_upgrade utility, are there any potential issues I might face in doing so?
The upgrades I'm considering are the following, official (generic) binary releases:
mysql-5.1.51-linux-i686-glibc23 -> mysql-5.1.61-linux-i686-glibc23
mysql-5.5.9-linux2.6-i686 -> mysql-5.5.21-linux2.6-i686