April 20, 2014

Percona Server 5.5.36-34.0 is now available

Percona is glad to announce the release of Percona Server 5.5.36-34.0 on March 10th, 2014 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.36, including all the bug fixes in it, Percona Server 5.5.36-34.0 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 […]

Generating test data for MySQL tables

One of the common tasks requested by our support customers is to optimize slow queries. We normally ask for the table structure(s), the problematic query and sample data to be able to reproduce the problem and resolve it by modifying the query, table structure, or global/session variables. Sometimes, we are given access to the server […]

16000 active connections – Percona Server continues to work when others die

We just published results with improvements in Thread Pool in Percona Server: Percona Server: Thread Pool Improvements for Transactional Workloads Percona Server: Improve Scalability with Thread Pool What I am happy to see is that Percona Server is able to handle a tremendous amount of user connections. From our charts you can see it can […]

Percona Server: Thread Pool Improvements for Transactional Workloads

In a previous thread pool post, I mentioned that in Percona Server we used an open source implementation of MariaDB’s thread pool, and enhanced/improved it further. Below I would like to describe some of these improvements for transactional workloads. When we were evaluating MariaDB’s thread pool implementation, we observed that it improves scalability for AUTOCOMMIT […]

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 […]

Percona Server: Improve Scalability with Percona Thread Pool

By default, for every client connection the MySQL server spawns a separate thread which will process all statements for this connection. This is the ‘one-thread-per-connection’ model. It’s simple and efficient until some number of connections N is reached. After this point performance of the MySQL server will degrade, mostly due to various contentions caused by […]

Beware of MySQL 5.6 server UUID when cloning slaves

The other day I was working on an issue where one of the slaves was showing unexpected lag. Interestingly with only the IO thread running the slave was doing significantly more IO as compared to the rate at which the IO thread was fetching the binary log events from the master. I found this out […]

2 cases for MySQL server overload

Your MySQL server is overloaded. You see hundreds of running queries in the SHOW PROCESSLIST taking many seconds to run, or can’t connect at all because all connections slots are busy. If you have worked with MySQL long enough you surely have seen it, probably more than once. This is what I would call “MySQL […]

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 […]

Percona Server 5.5.35-33.0 is now available

Percona is glad to announce the release of Percona Server 5.5.35-33.0 on December 20th, 2013 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.35, including all the bug fixes in it, Percona Server 5.5.35-33.0 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 […]