> > 1) does having two master servers make sense?
>
> It normally doesn't work as the master servers don't know of updates
> made to tables of the other master. Now if you can clearly separate
> all records between the two masters (i.e. table XX does only exist on
> master1, while YY only exists on master2), it should work. What I
> can't say without looking up in the doc is whether a slave can be
> slave of two masters at the same time.
Not true, you can do two-way replication and both masters will update each
other. See http://www.mysql.com/doc/R/e/Replication_FAQ.html, question "What
issues should I be aware of when setting up two-way replication?"
A slave can't have two masters, but since each master can replicate all
databases there would be no point.
