A few days ago I wrote about MySQL performance implications of InnoDB isolation modes and I touched briefly upon the bizarre performance regression I found with InnoDB handling a large amount of versions for a single row. Today I wanted to look a bit deeper into the problem, which I also filed as a bug. First [&]

The post Looking deeper into InnoDBs problem with many row versions appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2015/01/19/looking-deeper-innodbs-problem-many-row-versions/

As you may already be aware, FOSDEM and its wonderful MySQL and Friends track are once again descending upon the campus of the ULB in Brussels, Belgium. Logically, a traditional MySQL and Friends Community Dinner must follow! Signups for that dinner, on January 31, are now available, so be sure to get your tickets before they run out. [&]

The post FOSDEM 2015: MySQL and Friends Community Dinner! appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2015/01/16/fosdem-2015-mysql-friends-community-dinner/

The other day a customer asked me to do capacity planning for their web server farm. I was looking at the CPU graph for one of the web servers that had Hyper-threading switched ON and thought to myself: This must be quite a misleading graph  it shows 30% CPU usage. It cant really be [&]

The post Hyper-threading  how does it double CPU throughput? appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2015/01/15/hyper-threading-double-cpu-throughput/

Percona is glad to announce the release of Percona XtraBackup 2.2.8 on January 14, 2015. Downloads are available from our download site or Percona Software Repositories. Percona XtraBackup enables MySQL backups without blocking user queries, making it ideal for companies with large data sets and mission-critical applications that cannot tolerate long periods of downtime. Offered [&]

The post Percona XtraBackup 2.2.8 is now available appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2015/01/14/percona-xtrabackup-2-2-8-now-available/

Over the past few months Ive written a couple of posts about dangerous debt of InnoDB Transactional History and about the fact MVCC can be the cause of severe MySQL performance issues. In this post I will cover a related topic  InnoDB Transaction Isolation Modes, their relationship with MVCC (multi-version concurrency control) and how [&]

The post MySQL performance implications of InnoDB isolation modes appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2015/01/14/mysql-performance-implications-of-innodb-isolation-modes/

Today we announced the full conference sessions schedule for April’s Percona Live MySQL Conference & Expo 2015 and this year’s event, once again at the Hyatt Regency Santa Clara and Santa Clara Convention Center, looks to be the biggest yet with networking and learning opportunities for MySQL professionals and enthusiasts at all levels. Conference sessions [&]

The post Percona Live 2015 conference sessions announced! appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2015/01/13/percona-live-2015-conference-sessions-announced/

Percona is glad to announce the release of Percona Server 5.6.22-71.0 on January 12, 2015. Download the latest version from the Percona web site or from the Percona Software Repositories. Based on MySQL 5.6.22, including all the bug fixes in it, Percona Server 5.6.22-71.0 is the current GA release in the Percona Server 5.6 series. Percona Server is open-source [&]

The post Percona Server 5.6.22-71.0 is now available appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2015/01/12/percona-server-5-6-22-71-0-now-available/

Percona is glad to announce the release of Percona Server 5.5.41-37.0 on January 9, 2015. Based on MySQL 5.5.41, including all the bug fixes in it, Percona Server 5.5.41-37.0 is now the current stable release in the 5.5 series. Percona Server is open-source and free. Details of the release can be found in the 5.5.41-37.0 [&]

The post Percona Server 5.5.41-37.0 is now available appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2015/01/12/percona-server-5-5-41-37-0-now-available/

Whether youre looking at the overall MySQL ecosystem or the all-data management landscape, the choice of technologies has never been larger than it is in 2015. Having so many options is great but it also can be very hard to make a selection. Im going to help narrow the list next week during a Webinar [&]

The post Managing data using open source technologies? Learn whats hot in 2015! appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2015/01/08/managing-data-using-open-source-technologies-learn-whats-hot-2015/

This is yet another story of Django web-framework with time zone support and pain dealing with python datetimes and MySQL on the backend. In other words, offset-naive vs offset-aware datetimes. Shortly, more about the problem. After reading the official documentation about the time zones, it makes clear that in order to reflect python datetime in [&]

The post Django with time zone support and MySQL appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2015/01/07/django-with-time-zone-support-and-mysql/

We have been using SHOW ENGINE INNODB MUTEX command for years. It shows us mutex and rw-lock information that could be useful during service troubleshooting in case of performance problems. As Morgan Tocker announced in his blog post the command will be removed from MySQL 5.7 and we have to use performance_schema to get that [&]

The post Getting mutex information from MySQLs performance_schema appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2015/01/06/getting-mutex-information-from-mysqls-performance_schema/

Sometimes it is desired to use particular software versions in production, and not necessary the latest ones. There may be several reasons for that, where I think the most common is when a new version should spend some time in testing or a staging environment before getting to production. In theory each new version is [&]

The post Using YUM to install specific MySQL/Percona Server versions appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2015/01/05/using-yum-to-install-specific-mysqlpercona-server-versions/

Query caching is one of the prominent features in MySQL and a vital part of query optimization. It is important to know how it works as it has the potential to cause significant performance improvements  or a slowdown  of your workload. The MySQL query cache is a global one shared among the sessions. It caches [&]

The post The MySQL Query Cache: How it works, plus workload impacts (good and bad) appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2015/01/02/the-mysql-query-cache-how-it-works-and-workload-impacts-both-good-and-bad/

If youve been studying complex systems you know what minor changes might cause consequences of much greater proportions, sometimes causing some effects that are not easily explained at first. I recently ran across a great illustration of such behavior while doing MySQL benchmarks which I thought would be interesting to share. Im using a very [&]

The post How small changes impact complex systems  MySQL example appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2014/12/31/small-changes-impact-complex-systems-mysql-example/

State Snapshot Transfer (SST) is used in Percona XtraDB Cluster (PXC) when a new node joins the cluster or to resync a failed node if Incremental State Transfer (IST) is no longer available. SST is triggered automatically but there is no magic: If it is not configured properly, it will not work and new nodes [&]

The post Diagnosing SST errors with Percona XtraDB Cluster for MySQL appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2014/12/30/diagnosing-sst-errors-with-percona-xtradb-cluster-for-mysql/

Some time ago, Peter Zaitsev posted a blog titled How well does your table fits in innodb buffer pool? He used some special INFORMATION_SCHEMA tables developed for Percona Server 5.1 to report how much of each InnoDB table and index resides in your buffer pool. As Peter pointed out, you can use this view into [&]

The post How well does your table fit in the InnoDB buffer pool in MySQL 5.6+? appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2014/12/29/how-well-does-your-table-fit-in-innodb-buffer-pool-56/

It has been a while since I have looked at InnoDB crash recovery. A lot has change in the last few years  we have serious crash recovery performance improvements in MySQL 5.5 and MySQL 5.6, we have solid state drives raising as typical high performance IO subsystem and we also have the ability to [&]

The post InnoDB crash recovery speed in MySQL 5.6 appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2014/12/24/innodb-crash-recovery-speed-mysql-5-6/

This is a long overdue blog post from Londons 44con Cyber Security conference back in September. A lot of old memories were brought to the front as it were; the one Im going to cover in this blog post is: file carving. So what is file carving? despite the terminology its not going to be a [&]

The post File carving methods for the MySQL DBA appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2014/12/23/file-carving-methods-for-the-mysql-dba/

Background on Backup Locks I was very excited to see Backup locks support in release notes for the latest Percona XtraDB Cluster 5.6.21 release. For those who are not aware, backup locks offer an alternative to FLUSH TABLES WITH READ LOCK (FTWRL) in Xtrabackup. While Xtrabackup can hot-copy Innodb, everything else in MySQL must be locked (usually [&]

The post Testing backup locks during Xtrabackup SST on Percona XtraDB Cluster appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2014/12/22/testing-backup-locks-during-xtrabackup-sst-on-percona-xtradb-cluster/

A few years ago Peter Zaitsev, in a post titled To UUID or not to UUID, wrote: There is timestamp based part in UUID which has similar properties to auto_increment and which could be used to have values generated at same point in time physically local in BTREE index. For this post Ive rearranged the timestamp part [&]

The post Store UUID in an optimized way appeared first on MySQL Performance Blog.

http://www.percona.com/blog/2014/12/19/store-uuid-optimized-way/