[MySQL-replication] Addutional slave to a master-to-master replication

On 7 Mar 2010, at 22:04, Database System wrote:

I have one master A , and two slaves B and C both replicate A.

Now I want to change A and B as master to master replication. I know how to setup A and B. I'm not sure if I need to do any change on C, in order it execute all statements once and won't miss any statements. For example, updates on A, and updates original done on B, but replicated/executed on A.

Database System wrote:
Hi,

I have one master A , and two slaves B and C both replicate A.

Now I want to change A and B as master to master replication. I know how to setup A and B. I'm not sure if I need to do any change on C, in order it execute all statements once and won't miss any statements. For example, updates on A, and updates original done on B, but replicated/executed on A.

Thanks,
Lisa

From: Mats Kindahl <mats@sun.com>
Subject: Re: Addutional slave to a master-to-master replication
To: database100@yahoo.com
Cc: replication@lists.mysql.com
Date: Monday, March 8, 2010, 2:36 PM


Database System wrote:
replication. I know how to setup A and B. I'm not sure if I
need to do any change on C, in order it execute all
statements once and won't miss any statements. For example,
updates on A, and updates original done on B, but
replicated/executed on A.

Hi Lisa,

I'm not sure what problem you're trying to solve, but
replication
between A and B will work since A will prune any events
tagged with
its server ID. For events that originate from C you have to
be careful
since those events will not be pruned by any server if they
get into
the loop between A and B.

Note that you cannot replicate from two masters at the same
time
(unless you resort to various tricks), so you have to
re-direct the A
and B server to each others. If you are too quick in
re-directing the
A and B servers, it might be that there are C events in the
binlog for
either A or B, and they will then circle forever, and being
executed a
lot of times.

Just my few cents,
Mats Kindahl
--
Mats Kindahl
Senior Software Engineer
Database Technology Group
Sun Microsystems

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On 9 Mar 2010, at 19:58, Database System wrote:

I successfully setup master to master replication between A and B. Now I'd likr to add C to replicate A, mean A is also master of C. I need to make sure updates on B will also indirect replicated to C.