April 19, 2014

Crash-resistant replication: How to avoid MySQL replication errors

Percona Server’s “crash-resistant replication” feature is useful in versions 5.1 through 5.5. However, in Percona Server 5.6 it’s replaced with Oracle MySQL 5.6′s “crash safe replication” feature, which has it’s own implementation (you can read more about it here). A MySQL slave normally stores its position in files master.info and relay-log.info which are updated by […]

Percona Server 5.1.70-14.8 now available

Percona is glad to announce the release of Percona Server 5.1.70-14.8 on July 3nd, 2013 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.1.70, including all the bug fixes in it, Percona Server 5.1.70-14.8 is now the current stable release in the 5.1 series. All of Percona‘s software is open-source and free, all the details of the release […]

Troubleshooting MySQL Upgrade Performance Regressions

So lets say you upgraded from MySQL 5.1 to Percona Server 5.5 and instead of expected performance improvement you see your performance being worse. What should you do ? First if you followed MySQL upgrade best practices such as testing your workload with pt-upgrade the chances of this happening are rather slim. But lets assume […]

Percona Server 5.1.60-13.1

Percona is glad to announce the release of Percona Server 5.1.60-13.1 on December 16, 2011 (Downloads are available from Percona Server 5.1.60-13.1 downloads and from the Percona Software Repositories). Based on MySQL 5.1.60, including all the bug fixes in it, Percona Server 5.1.60-13.1 is now the current stable release in the 5.1 series. All of Percona ‘s software is open-source and free, all the details […]

Percona Server 5.5.17-22.1 released

Percona is glad to announce the release of Percona Server 5.5.17-22.1 on November 19th, 2011 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.17, including all the bug fixes in it, Percona Server 5.5.17-22.1 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 […]

High Rate insertion with MySQL and Innodb

I again work with the system which needs high insertion rate for data which generally fits in memory. Last time I worked with similar system it used MyISAM and the system was built using multiple tables. Using multiple key caches was the good solution at that time and we could get over 200K of inserts/sec. […]

Impact of the sort buffer size in MySQL

The parameter sort_buffer_size is one the MySQL parameters that is far from obvious to adjust. It is a per session buffer that is allocated every time it is needed. The problem with the sort buffer comes from the way Linux allocates memory. Monty Taylor (here) have described the underlying issue in detail, but basically above […]

Why you should ignore MySQL’s key cache hit ratio

I have not caused a fist fight in a while, so it’s time to take off the gloves. I claim that somewhere around of 99% of advice about tuning MySQL’s key cache hit ratio is wrong, even when you hear it from experts. There are two major problems with the key buffer hit ratio, and […]

Air traffic queries in MyISAM and Tokutek (TokuDB)

This is next post in series Analyzing air traffic performance with InfoBright and MonetDB Air traffic queries in LucidDB Air traffic queries in InfiniDB: early alpha Let me explain the reason of choosing these engines. After initial three posts I am often asked “What is baseline ? Can we compare results with standard MySQL engines […]

Crashes while using MyISAM with multiple key caches

Over last couple of years I have ran into random MySQL crashes in production when multiple key caches were used. Unfortunately this never was frequent or critical enough issue so I could spend time creating repeatable test case and search of the bug in the MySQL database did not find anything. Recently we had this […]