April 20, 2014

MySQL 5.5 lock_wait_timeout: patience is a virtue, and a locked server

Like Ovais said in Implications of Metadata Locking Changes in MySQL 5.5, the hot topic these days is MySQL 5.6, but there was an important metadata locking change in MySQL 5.5.  As I began to dig into the Percona Toolkit bug he reported concerning this change apropos pt-online-schema-change, I discovered something about lock_wait_timeout that shocked me.  From the […]

MySQL 5.5 and MySQL 5.6 default variable values differences

As the part of analyzing surprising MySQL 5.5 vs MySQL 5.6 performance results I’ve been looking at changes to default variable values. To do that I’ve loaded the values from MySQL 5.5.30 and MySQL 5.6.10 to the different tables and ran the query:

Lets go over to see what are the most important changes […]

Is MySQL 5.6 slower than MySQL 5.5?

There have been a number reports/benchmarks showing MySQL 5.6 to be slower than MySQL 5.5 on variety of workloads. There are many possible reasons and I believe we will learn about many of them in the next few weeks and months as MySQL 5.6 is starting to get production battle-tested and there is inflow of […]

Replication checksums in MySQL 5.6

MySQL 5.6 has an impressive list of improvements. Among them, replication checksums caught my attention as it seems that many people misunderstand the real added value of this new feature. I heard people think that with replication checksums, data integrity between the master and its replicas is now enforced. As we’ll see, it’s not that […]

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 […]

Percona Toolkit 2.1.8 released today with beta support for MySQL 5.6

Percona Toolkit 2.1.8 was released today and the new version comes with some pretty cool news: Beta support for MySQL 5.6 (which as you might know is also in beta). In addition to various bug fixes, Percona Toolkit 2.1.8 also offers beta support for Percona XtraDB Cluster (PXC). Version 2.1.8 continues the trend of solid […]

How does MySQL Replication really work?

While we do have many blog posts on replication on our blog, such as on replication being single-threaded, on semi-synchronous replication or on estimating replication capacity, I don’t think we have one that covers the very basics of how MySQL replication really works on the high level. Or it’s been so long ago I can’t […]

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 […]

Announcing Percona Server 5.5.27-28.0

Percona is glad to announce the release of Percona Server 5.5.27-28.0 on August 23rd, 2012 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.27, including all the bug fixes in it, Percona Server 5.5.27-28.0 is now the current stable release in the 5.5 series. All of Percona‘s software is open-source and free, all the details of the release can […]

Introducing the pmp-check-mysql-status Nagios Plugin

Most of the Nagios plugins included with the Percona Monitoring Plugins are purpose-built for specific scenarios that I found in my research to be frequent, severe, or subtle causes of problems in MySQL systems. They are intentionally not generic because I wanted to focus on doing one thing with each plugin, and doing it excellently. […]