Comments on: How to scale writes with master-master replication in MySQL http://www.xaprb.com/blog/2008/08/06/how-to-scale-writes-with-master-master-replication-in-mysql/ Stay curious! Thu, 09 Feb 2012 20:41:20 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Nicolas http://www.xaprb.com/blog/2008/08/06/how-to-scale-writes-with-master-master-replication-in-mysql/#comment-19848 Nicolas Sun, 22 Jan 2012 23:56:01 +0000 http://www.xaprb.com/blog/2008/08/06/how-to-scale-writes-with-master-master-replication-in-mysql/#comment-19848 Wouldn't the master-master help scaling in some case. There is lot of queries that requires read before writes like insert...select or updates. Wouldn't splitting the writes between two master and using row-based replication help? The two masters will still have to do all the write (hence, write doesn't scale) but you can improve your throughput by reducing some of the read generated by the write (and possibly reduce CPU impact of some bad triggers). Would this be a fallacy too? Also, the post is few years old. MySQL 5.6 is on its way with multi-threaded replication. Having write for one DB on one master and write for another DB to the other master could help the replication lag issues. IMHO, master-master can mitigate the I/O problem in some case but doesn't solve it. You still need to get all your data written on both master. Wouldn’t the master-master help scaling in some case. There is lot of queries that requires read before writes like insert…select or updates. Wouldn’t splitting the writes between two master and using row-based replication help? The two masters will still have to do all the write (hence, write doesn’t scale) but you can improve your throughput by reducing some of the read generated by the write (and possibly reduce CPU impact of some bad triggers). Would this be a fallacy too?

Also, the post is few years old. MySQL 5.6 is on its way with multi-threaded replication. Having write for one DB on one master and write for another DB to the other master could help the replication lag issues.

IMHO, master-master can mitigate the I/O problem in some case but doesn’t solve it. You still need to get all your data written on both master.

]]> By: Xaprb http://www.xaprb.com/blog/2008/08/06/how-to-scale-writes-with-master-master-replication-in-mysql/#comment-18812 Xaprb Fri, 22 Oct 2010 10:17:24 +0000 http://www.xaprb.com/blog/2008/08/06/how-to-scale-writes-with-master-master-replication-in-mysql/#comment-18812 Pradeep, please use a mailing list or forum to get help with this. Pradeep, please use a mailing list or forum to get help with this.

]]> By: pradeep http://www.xaprb.com/blog/2008/08/06/how-to-scale-writes-with-master-master-replication-in-mysql/#comment-18811 pradeep Fri, 22 Oct 2010 08:06:22 +0000 http://www.xaprb.com/blog/2008/08/06/how-to-scale-writes-with-master-master-replication-in-mysql/#comment-18811 Hi! i am new in mysql and trying to establish master master replication in mysql on first server i have added these lines to mysqld section of my.cnf... [Ed: deleted rest of comment] Hi! i am new in mysql and trying to establish master master replication in mysql

on first server i have added these lines to mysqld section of my.cnf…

[Ed: deleted rest of comment]

]]> By: Xaprb http://www.xaprb.com/blog/2008/08/06/how-to-scale-writes-with-master-master-replication-in-mysql/#comment-15506 Xaprb Fri, 05 Dec 2008 19:18:45 +0000 http://www.xaprb.com/blog/2008/08/06/how-to-scale-writes-with-master-master-replication-in-mysql/#comment-15506 Hi Dmitri, I'm sorry, but that is a very long conversation. It is more advice than I want to give on my blog, since I am a consultant and give this advice via percona.com for a living :) You can also learn a lot about this via the MySQL manual, or by reading our book, but I don't want to repeat it here. Hi Dmitri,

I’m sorry, but that is a very long conversation. It is more advice than I want to give on my blog, since I am a consultant and give this advice via percona.com for a living :) You can also learn a lot about this via the MySQL manual, or by reading our book, but I don’t want to repeat it here.

]]> By: Dmitri http://www.xaprb.com/blog/2008/08/06/how-to-scale-writes-with-master-master-replication-in-mysql/#comment-15505 Dmitri Fri, 05 Dec 2008 18:33:04 +0000 http://www.xaprb.com/blog/2008/08/06/how-to-scale-writes-with-master-master-replication-in-mysql/#comment-15505 @Xaprb: thank you for the reply. In this case I think I will be interested in implementing two masters with one slave. My idea is to have one active master for all writes, a passive master for all reads and another slave for backups and cron jobs that involve big table scans and put additional load to mysql. I found brief description of this scheme at: http://code.google.com/p/mysql-master-master/wiki/TypicalUseCases However one thing that I am concerned of is that the description states: "IT could not be implemented without using some third party software or MySQL Cluster solutions (with well known set of limitations on database size)". I don't want to use Mysql Cluster. What kind of 3-rd party software is needed for this scheme? @Xaprb: thank you for the reply. In this case I think I will be interested in implementing two masters with one slave. My idea is to have one active master for all writes, a passive master for all reads and another slave for backups and cron jobs that involve big table scans and put additional load to mysql. I found brief description of this scheme at:

http://code.google.com/p/mysql-master-master/wiki/TypicalUseCases

However one thing that I am concerned of is that the description states: “IT could not be implemented without using some third party software or MySQL Cluster solutions (with well known set of limitations on database size)”.

I don’t want to use Mysql Cluster. What kind of 3-rd party software is needed for this scheme?

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