Hi, I'm running haproxy infront of 2 mysql servers in master master replication, the other one for backup incase primary mysql server goes down ( and when it goes down, reboots etc. ). Everything works as expected but I was reading today that you should never write to both masters... do you have an opinion on that, why you shouldn't write on master2 if master1 is down? and... can I let Ispconfig create mysql users on mirror only with select permissions if I decide on failover master2 is read-only unless I manually change permissions. Regards, Kristinn.
I don't see a problem if master-master replication is set up correctly. The server-id, auto-increment-increment, and auto-increment-offset directives are important - see http://www.howtoforge.com/mysql5_master_master_replication_debian_etch
