That's only applicable to MySql 5.0+ As I read the docs,
autoincrement fields are only an issue if you have multiple
replication MASTERS.
even then you don't want to use multiple masters. unless you really
really know what you're doing. if you know mediawiki that well, you
might probably assist with coding.
So you can have one or more slave servers which
replicate a single
master, and do things like load balancing queries across all the
servers, and taking backups from a suspended slave without stopping or
locking the master. Updates and inserts have to go to the single
master.
well, you can do backups from innodb without stopping or locking the
master. and yes, you can load balance, and the code for that is
already inside MediaWiki.
Domas