May 18, 2013

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 [...]

Solving INFORMATION_SCHEMA slowness

Many of us find INFORMATION_SCHEMA painfully slow to work it when it comes to retrieving table meta data. Many people resort to using file system tools instead to find for example how much space innodb tables are using and things like it. Besides being just slow accessing information_schema can often impact server performance dramatically. The [...]

Side load may massively impact your MySQL Performance

When we’re looking at benchmarks we typically run some stable workload and we run it in isolation – nothing else is happening on the system. This is not however how things happen in real world when we have significant variance in the load and many things can be happening concurrently. It is very typical to [...]

When Does InnoDB Update Table Statistics? (And When It Can Bite)

An InnoDB table statistics is used for JOIN optimizations and helping the MySQL optimizer choose the appropriate index for a query. If a table’s statistics or index cardinality becomes outdated, you might see queries which previously performed well suddenly show up on slow query log until InnoDB again updates the statistics. But when does InnoDB [...]

Reasons for MySQL Replication Lag

One common theme in the questions our MySQL Support customers ask is MySQL Replication Lag. The story is typically along the lines everything is same as before and for some unknown reason the slave is started to lag and not catching up any more. I always smile at “nothing has changed” claim as it usually [...]

Percona Server 5.5.8 Beta Release

It’s finally here! Percona Server Percona Server 5.5.8-20.0 is now available for download. This is a beta release of Percona’s enhancements to the MySQL 5.5.8 server. Here are some highlights: Performance and scalability improvements throughout the server and storage engine Optimizations for flash storage such as SSD, Virident, and FusionIO Optimizations for cloud computing The [...]

Percona Server 5.1.53-12.4

Percona Server version 5.1.53-12.4 is now available for download. It is now the current stable release version. Functionality Added or Changed  Percona Server 5.1.53-12.4 is based on MySQL 5.1.53.  New Features Added: Precompiled UDFs for Maatkit (FNV and MurmurHash hash functions to provide faster checksums) are now included in distributions. Fixes feature request #689992. (Aleksandr Kuzminsky) [...]

Percona Server 5.1.53-11.7

Percona Server version 5.1.53-11.7 is now available for download. The main purpose of this release is to update the current Percona stable release to the latest version of MySQL 5.1. Functionality Added or Changed  Percona Server 5.1.53-11.7 is now based on MySQL 5.1.53.  New Features Added: None  Other Changes: None Bugs Fixed Bug #643149 – [...]

Estimating Replication Capacity

It is easy for MySQL replication to become bottleneck when Master server is not seriously loaded and the more cores and hard drives the get the larger the difference becomes, as long as replication remains single thread process. At the same time it is a lot easier to optimize your system when your replication runs [...]

Percona-XtraDB-9.1: released and new coming features

Recently Alexandr announced new Percona-XtraDB-9.1 release, and now it is good time to summarize features we have and what is expected soon. This release contains long waited features from 5.0: extended slow.log USER/TABLE/INDEX/CLIENT_STATISTICS + THREAD_STATISTICS ( coming in release-10) Extended slow.log is now even more extended, there is additional information for each query:

That [...]