Hey Steven: I have numerous replicating setups in a number of places and generally consider the solution as a stable one. Uptimes (synced) are very good even on the very busy mail servers. Actually I have never had a server break 'sync' save when I caused it by doing some kind of radical surgery on something.
Failover, however is not very straightforward. I would love to hear your ideas. I rely to some extent on MX2 and have Postfix queue the mail until a decision is made on whether the downed server is to be returned to service; or a slave promoted to master and pushed up to MX1 production as the master is permanently killed. I keep an alternate 'my.cnf' on the slaves. In some cases the slave runs the MX2. Certainly when a replication slave breaks it can be a real pain because in most cases a tarball of a locked master's data must be used to update the slave. Usually, in my experience, the break has a reason; something significant and glaring. 1) I find that replication works best when the version of the master and slaves are identical. (i.e.: all v4.0.20 or whatever) 2) RW on the master; read-only on a slave. 3) Although there are many permutations possible, it is better to replicate the entire database and *not* have any additional databases on the slaves. 4) Don't mix character sets. Use the same global character set on all servers and use the same character set as global for all sessions. 5) Start out from a perfect mirror database set. I am sure you have a master/slave create routine but you might take a look at this one I know functions well and see if you are leaving something out. * stop the slave ON MASTER mysql > show master status\G *************************** 1. row *************************** File: master-bin.190 Position: 28903417 Binlog_do_db: Binlog_ignore_db: 1 row in set (0.00 sec) mysql > Note the first two lines. * Lock or stop the master and tarball the FULL contents of the data folder. ( i.e: cd ../data & /usr/bin/tar -cvf /export/home/tmp/mysql-snapshot.tar . ) * move the tarball to the slave's data folder and untar it there. * start the slave * start the master NOW GO TO SLAVE CONSOLE # mysql -u root -p password secret etc mysql > stop slave; mysql > CHANGE MASTER TO MASTER_HOST='xxx.xxx.xxx.xxx.', MASTER_USER='dbmaster', MASTER_PASSWORD='dbpass', MASTER_LOG_FILE='master-bin.190', MASTER_LOG_POS=28903417; mysql > blah blah rows (secs) mysql > start slave; mysql > show slave status\G hope this helps... Mike ----- Original Message ----- From: "Steven Lynn" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Wednesday, January 19, 2005 1:22 AM Subject: [Dbmail] dbMail with MySQL Replication... > I know that this is probably a MySQL question, but I figured I would > start here. Hope no one minds... > > Is anybody using multiple dbmail servers that are also running MySQL > with replication? I have two servers and trying to do fail over between > the two. I can not seem to keep the two servers in sync. If I leave both > running, within 24 hours, one is out of sync... > > Anybody got any ideas? Once again, sorry for this question... > > -- > Steven Lynn > [EMAIL PROTECTED] > > ---------------------------------------------------------------------------- ---- > _______________________________________________ > Dbmail mailing list > [email protected] > https://mailman.fastxs.nl/mailman/listinfo/dbmail >
