May 20, 2013

How to create/restore a slave using GTID replication in MySQL 5.6

MySQL 5.6 is GA! Now we have new things to play with and in my personal opinion the most interesting one is the new Global Transaction ID (GTID) support in replication. This post is not an explanation of what is GTID and how it works internally because there are many documents about that: http://dev.mysql.com/doc/refman/5.6/en/replication-gtids-concepts.html One [...]

Read/Write Splitting with PHP Webinar Questions Followup

Today I gave a presentation on “Read/Write Splitting with PHP” for Percona Webinars.  If you missed it, you can still register to view the recording and my slides. Thanks to everyone who attended, and especially to folks who asked the great questions.  I answered as many as I could during the session, but here are [...]

Sphinx search performance optimization: multi-threaded search

Queries in MySQL, Sphinx and many other database or search engines are typically single-threaded. That is when you issue a single query on your brand new r910 with 32 CPU cores and 16 disks, the maximum that is going to be used to process this query at any given point is 1 CPU core and [...]

MySQL Wish for 2013 – Better Memory Accounting

With Performance Schema improvements in MySQL 5.6 I think we’re in the good shape with insight on what is causing performance bottlenecks as well as where CPU resources are spent. (Performance Schema does not accounts CPU usage directly but it is something which can be relatively easily derived from wait and stage information). Where we’re [...]

Migrating several single standalone MySQL server to one Percona XtraDB Cluster… MariaDB to the rescue !

Some weeks ago I had to migrate some independent MySQL servers (some standard MySQL masters, and some just standalone) to a Percona XtraDB Cluster of 3 nodes. So the easiest way would be to configure each node to become also an asynchronous slave of one of the production servers. Like illustrated here: But in this [...]

Announcing Percona XtraDB Cluster 5.5.28-23.7

Percona is glad to announce the release of Percona XtraDB Cluster on November 15th, 2012. Binaries are available from downloads area or from our software repositories. Features: Percona XtraDB Cluster has ported Twitter’s MySQL NUMA patch. This patch implements improved NUMA support as it prevents imbalanced memory allocation across NUMA nodes. Number of binlog files [...]

Debugging MySQL SSL problems

This is not necessarily going to be a comprehensive post, but I learned somethings about MySQL SSL today that I thought would be worth sharing. I was setting up a PRM install for a customer and one of the requirements was SSL replication.  In this particular case, I had setup PRM first, and then was [...]

Percona XtraDB Cluster – installation and setup webinar follow up Q&A

Thanks for all, who attended my webinar, I got many questions and I wanted to take this opportunity to answer them. Q: Even ntp has a delay of 0.3-0.4 between servers does that mean a 0.25 as from logs can be an issue ? A: My demo vms were running for a few hours before [...]

Review of MySQL 5.6 Defaults Changes

James Day just posted the great summary of defaults changes in MySQL 5.6 compared to MySQL 5.5 In general there are a lot of good changes and many defaults are now computed instead of hardcoded. Though some of changes are rather puzzling for me. Lets go over them: back_log = 50 + ( max_connections / [...]

Automation: A case for synchronous replication

Just yesterday I wrote about math of automatic failover today I’ll share my thoughts about what makes MySQL failover different from many other components and why asynchronous nature of standard replication solution is causing problems with it. Lets first think about properties of simple components we fail over – web servers, application servers etc. We [...]