September 2, 2014

MySQL server memory usage troubleshooting tips

There are many blog posts already written on topics related to “MySQL server memory usage,” but nevertheless there are some who still get confused when troubleshooting issues associated with memory usage for MySQL. As a Percona support engineer, I’m seeing many issues regularly related to heavy server loads – OR OOM killer got invoked and […]

Renaming database schema in MySQL

One of the routine tasks for a DBA is renaming database schemas, and as such MySQL added a command to carry out that purpose called “RENAME DATABASE <database_name>”. However this command just made it through a few minor releases before being discontinued (from MySQL 5.1.7 to 5.1.23). Here’s a link to the reference manual regarding […]

MySQL Error: Too many connections

We have always received quite few questions here at Percona Support on how to avoid the dreaded “Too many connections” error, as well as what is the recommended value for max_connections. So, in this article I will try to cover best possible answers to these questions so others can mitigate similar kinds of issues. My […]

How to Extract All Running Queries (Including the Last Executed Statement) from a Core File?

This post builds on the How to obtain the “LES” (Last Executed Statement) from an Optimized Core Dump? post written about a year ago. A day after that post was released, Shane Bester wrote an improved version, How to obtain all executing queries from a core file on his blog. Reading that post is key […]

Innotop: A real-time, advanced investigation tool for MySQL

GUI monitoring tools for MySQL are not always suitable for all our needs or situations. Most of them are designed to provide historical views into what happens to our database over time rather then real-time insight into current MySQL server status. Excellent free tools for this include Cacti, Zabbix, Ganglia, Nagios, etc. But each of […]

Here’s my favorite secret MySQL 5.6 feature. What’s yours?

MySQL 5.6 has a great many new features, including, but certainly not limited to a number of performance improvements. However, besides the widely talked-about features such as InnoDB support for full text search, optimizer, performance schema improvements and GTID, there are also a few tiny improvements that nobody cared to mention. One such feature is…

Migrating between MySQL schemas with Percona Xtrabackup

Recently, I was working with a client that asked about using Percona Xtrabackup to take a snapshot of a particular MySQL schema and then reload it with a different schema name on the same server.  It caught me off guard because I’d never really thought about it – typically, I’ve used Xtrabackup simply to clone […]

Experiences with the McAfee MySQL Audit Plugin

I recently had to do some customer work involving the McAfee MySQL Audit Plugin and would like to share my experience in this post. Auditing user activity in MySQL  has traditionally been challenging. Most data can be obtained from the slow or general log, but this involves a lot of data you don’t need too, and […]

MySQL and the SSB – Part 2 – MyISAM vs InnoDB low concurrency

This blog post is part two in what is now a continuing series on the Star Schema Benchmark. In my previous blog post I compared MySQL 5.5.30 to MySQL 5.6.10, both with default settings using only the InnoDB storage engine.  In my testing I discovered that innodb_old_blocks_time had an effect on performance of the benchmark.  There was […]

Percona XtraBackup 2.1.0 ‘release candidate’ for MySQL available for download

Percona is glad to announce the release of Percona XtraBackup 2.1.0-rc1 on May 7, 2013. Downloads are available from our download site here. For this RC release, we will not be making APT and YUM repositories available, just base deb and RPM packages This is an Release Candidate quality release and is not intended for […]