MySQL To Percona Server Gottcha

Decided to replace the aging MySQL 5.1.x on a CentOS Box with a newer Percona Server 5.6. First step was to update MySQL 5.1 to 5.5. This went relatively smoothly after I figured out some mySQL transaction kung-fu and ran mysql_upgrade. Step two was to replace it with Percona Server. It installed fine. Almost to simple. So naturally I ran:

etc/init.d/mysql start

which resulted in a dreaded:

Starting MySQL (Percona Server).... ERROR! The server quit without updating PID file (/var/lib/mysql/SERVERNAME.pid)

After a few minutes of pouring through the logs I noticed this little nugget:

2015-04-25 19:18:16 18234 [ERROR] /usr/sbin/mysqld: unknown variable 'table_cache=7K'

Apparently around MySQL 5.1.3 they replaced table_cache with table_open_cache. A simple rename in my.ini, and we’re on our way. Now running a little faster thanks to some much newer DB binaries.