November 27, 2014

A schema change inconsistency with Galera Cluster for MySQL

I recently worked on a case where one node of a Galera cluster had its schema desynchronized with the other nodes. And that was although Total Order Isolation method was in effect to perform the schema changes. Let’s see what happened. Background For those of you who are not familiar with how Galera can perform […]

Looking for RAID Controller without Battery Learning problems ?

A lot have been written about Battery Learning Cycle problems and its impact to MySQL Performance. Here are couple of links (1,2). It is good to see though there are some controllers coming out which solve this problem, namely Adaptec 5Z series controllers (Z stands for Zero Maintenance). This is not quite new technology they […]

Innodb redo log archiving

Percona Server 5.6.11-60.3 introduces a new “log archiving” feature. Percona XtraBackup 2.1.5 supports “apply archived logs.” What does it mean and how it can be used? Percona products propose three kinds of incremental backups. The first is full scan of data files and comparison the data with backup data to find some delta. This approach […]

Introducing backup locks in Percona Server

TL;DR version: The backup locks feature introduced in Percona Server 5.6.16-64.0 is a lightweight alternative to FLUSH TABLES WITH READ LOCK and can be used to take both physical and logical backups with less downtime on busy servers. To employ the feature with mysqldump, use mysqldump –lock-for-backup –single-transaction. The next release of Percona XtraBackup will […]

High-availability options for MySQL, October 2013 update

The technologies allowing to build highly-available (HA) MySQL solutions are in constant evolution and they cover very different needs and use cases. In order to help people choose the best HA solution for their needs, we decided, Jay Janssen and I, to publish, on a regular basis (hopefully, this is the first), an update on […]

InnoDB performance optimization basics (redux)

I recently stumbled upon a post that Peter Zaitsev published back in 2007 titled “Innodb Performance Optimization Basics.” It’s a great post and reading it inspired me to examine what’s changed in the nearly six years that have followed in terms of MySQL, Percona Server – as well as in all of the other now-available […]

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 […]

Percona XtraDB Cluster Feature 2: Multi-Master replication

This is about the second great feature – Multi-Master replication, what you get with Percona XtraDB Cluster. It is recommended you get familiar with general architecture of the cluster, described on the previous post. By Multi-Master I mean the ability to write to any node in your cluster and do not worry that eventually you […]

Innodb Performance Optimization Basics

Note: There is an updated post on this topic here. Interviewing people for our Job Openings I like to ask them a basic question – if you have a server with 16GB of RAM which will be dedicated for MySQL with large Innodb database using typical Web workload what settings you would adjust and interestingly […]

How reliable RAID really is

This post is not exactly about MySQL Performance or about Performance at all, but I guess it should be interested to many MySQL DBAs and other people involved running MySQL In production. Recently I’ve been involved in troubleshooting Dell Poweredge 2850 system running RAID5 using 6GB internal hard drives, which give about 1.4TB of usable […]