You can setup C as slave of B, in order to avoid extra traffic on master (A), as you said.
After that, as you have only A active (writes is going through this server, right?), you
can stop slave on B and wait for C to catch up. At this time you can issue a change
master on C redirecting it to the same point where B is, since both are in the same
position considering A binary log. Finally, break replication B->A and setup C->A
and retire B server.
That is it. Hope it helps!
--- Em ter, 7/9/10, Marcus Bointon <marcus@stripped> escreveu:
De: Marcus Bointon <marcus@stripped>
Assunto: Restore with a different master
Para: "Replication replication" <replication@stripped>
Data: Terça-feira, 7 de Setembro de 2010, 14:17
I have a pair of servers running standard active/passive circular replication using mmm,
call them A and B. I want to introduce new server C, ultimately to replace B. I'm setting
it up by restoring an xtrabackup snapshot taken from B (using the practice of doing
backups on a slave to keep backup traffic off the active master). I know the details of
the master log and position for the backup, but it's from B not A, and though there must
be one, I've no way of knowing what the corresponding log and position on A is.
Here's the background: I want to move from:
A <-> B
to (slave C from A)
C <- A <-> B
to (break replication back from B)
C <- A -> B
to (close loop from A to C)
C <-> A -> B
to (remove B)
C <-> A
As far as I can see I can either:
• Take a new backup from A
• Switch B to be active master and retire A instead (A and B are identical)
Any other suggestions?
Synchromedia Limited: Creators of http://www.smartmessages.net/
UK resellers of info@hand CRM solutions
marcus@stripped | http://www.synchromedia.co.uk/