Percona is glad to announce the release of Percona XtraDB Cluster 5.5.30-23.7.4 for MySQL on April 17, 2013. Binaries are available from the downloads area or from our software repositories. New Features: Percona XtraDB Cluster has implemented initial implementation of weighted quorum. Weight for node can be assigned via pc.weight option in the wsrep_provider_options variable. [...]
How to obtain the “LES” (Last Executed Statement) from an Optimized Core Dump?
Ever ran into a situation where you saw “some important variable you really needed to know about=<optimized out>” while debugging?
Announcing Percona Server 5.5.25a-27.1
Percona is glad to announce the release of Percona Server 5.5.25a-27.1 on July 21st, 2012 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.25a, including all the bug fixes in it, Percona Server 5.5.25a-27.1 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 [...]
Troubleshooting MySQL Memory Usage
One of the most painful troubleshooting tasks with MySQL is troubleshooting memory usage. The problem usually starts like this – you have configured MySQL to use reasonable global buffers, such as innodb_buffer_size, key_buffer_size etc, you have reasonable amount of connections but yet MySQL takes much more memory than you would expect, causing swapping or other [...]
Percona testing: Quick test clusters with kewpie!
The announcement of Percona XtraDB Cluster seems to have generated a fair bit of interest : ) Although the documentation contains more formal instructions for setting up a test cluster, I wanted to share a quick way to set up an ad-hoc cluster on a single machine to help people play with this (imho) rather [...]
Improved InnoDB fast index creation
One of the serious limitations in the fast index creation feature introduced in the InnoDB plugin is that it only works when indexes are explicitly created using ALTER TABLE or CREATE INDEX. Peter has already blogged about it before, here I’ll just briefly reiterate other cases that might benefit from that feature: when ALTER TABLE [...]
Ultimate MySQL variable and status reference list
I am constantly referring to the amazing MySQL manual, especially the option and variable reference table. But just as frequently, I want to look up blog posts on variables, or look for content in the Percona documentation or forums. So I present to you what is now my newest Firefox toolbar bookmark: an option and [...]
Tuning InnoDB Concurrency Tickets
InnoDB has an oft-unused parameter innodb_concurrency_tickets that seems widely misunderstood. From the docs: “The number of threads that can enter InnoDB concurrently is determined by the innodb_thread_concurrency variable. A thread is placed in a queue when it tries to enter InnoDB if the number of threads has already reached the concurrency limit. When a thread [...]
How much memory can MySQL use in the worst case?
I vaguely recall a couple of blog posts recently asking something like “what’s the formula to compute mysqld’s worst-case maximum memory usage?” Various formulas are in wide use, but none of them is fully correct. Here’s why: you can’t write an equation for it.
How Percona does a MySQL Performance Audit
Our customers or prospective customers often ask us how we do a performance audit (it’s our most popular service). I thought I should write a blog post that will both answer their question, so I can just reply “read all about it at this URL” and share our methodology with readers a little bit. This [...]

