Comments on: Speed up your MySQL replication slaves http://www.xaprb.com/blog/2008/01/13/speed-up-your-mysql-replication-slaves/ Stay curious! Tue, 07 Oct 2008 03:02:05 +0000 http://wordpress.org/?v=2.6.2 By: Xaprb http://www.xaprb.com/blog/2008/01/13/speed-up-your-mysql-replication-slaves/#comment-14162 Xaprb Mon, 14 Jan 2008 14:10:23 +0000 http://www.xaprb.com/blog/2008/01/13/speed-up-your-mysql-replication-slaves/#comment-14162 Kevin, I wrote more about the workload in the next post. You're right about in-memory -- it works only if data is lots bigger than memory. Kevin, I wrote more about the workload in the next post. You’re right about in-memory — it works only if data is lots bigger than memory.

]]> By: Kevin Burton http://www.xaprb.com/blog/2008/01/13/speed-up-your-mysql-replication-slaves/#comment-14160 Kevin Burton Mon, 14 Jan 2008 10:24:29 +0000 http://www.xaprb.com/blog/2008/01/13/speed-up-your-mysql-replication-slaves/#comment-14160 Another note. This will NOT fix performance on DBs that are all in memory. This is how we see most of our performance benefits. Another note. This will NOT fix performance on DBs that are all in memory. This is how we see most of our performance benefits.

]]> By: Kevin Burton http://www.xaprb.com/blog/2008/01/13/speed-up-your-mysql-replication-slaves/#comment-14159 Kevin Burton Mon, 14 Jan 2008 10:22:52 +0000 http://www.xaprb.com/blog/2008/01/13/speed-up-your-mysql-replication-slaves/#comment-14159 I saw that presentation. Not much meat there. Anyway. what's the right load ? Mostly write bound? I saw that presentation. Not much meat there.

Anyway. what’s the right load ? Mostly write bound?

]]> By: Xaprb http://www.xaprb.com/blog/2008/01/13/speed-up-your-mysql-replication-slaves/#comment-14157 Xaprb Mon, 14 Jan 2008 00:22:39 +0000 http://www.xaprb.com/blog/2008/01/13/speed-up-your-mysql-replication-slaves/#comment-14157 Dale, it's actually a bit of a misnomer. It's not pre-fetching the relay log -- MySQL already does that extremely fast, as you know. It's pre-executing the write queries as SELECT queries to address precisely the issue you mentioned: single-threaded execution on the slave. In a bit more detail: pre-executing these queries can, if the conditions are right, cause MySQL to fetch at least some of the necessary data from the disk, so it's already in memory when the slave SQL thread wants to update it. I should really explain this in more detail. I'll write another post on the topic and give proper references this time :-) Chris, you are absolutely correct. Dale, it’s actually a bit of a misnomer. It’s not pre-fetching the relay log — MySQL already does that extremely fast, as you know. It’s pre-executing the write queries as SELECT queries to address precisely the issue you mentioned: single-threaded execution on the slave.

In a bit more detail: pre-executing these queries can, if the conditions are right, cause MySQL to fetch at least some of the necessary data from the disk, so it’s already in memory when the slave SQL thread wants to update it.

I should really explain this in more detail. I’ll write another post on the topic and give proper references this time :-)

Chris, you are absolutely correct.

]]> By: Xaprb http://www.xaprb.com/blog/2008/01/13/speed-up-your-mysql-replication-slaves/#comment-14156 Xaprb Mon, 14 Jan 2008 00:19:11 +0000 http://www.xaprb.com/blog/2008/01/13/speed-up-your-mysql-replication-slaves/#comment-14156 Sean, thanks. Sean, thanks.

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