Today I gave a presentation on “Read/Write Splitting with PHP” for Percona Webinars. If you missed it, you can still register to view the recording and my slides. Thanks to everyone who attended, and especially to folks who asked the great questions. I answered as many as I could during the session, but here are [...]
Common MySQL traps webinar questions followup
Thanks to all attendees of the webinar yesterday! If you missed it, you can watch the video recording. Here are some questions that remained unanswered due to time constraints. Q: Are there any technical considerations or best practice tips to have a replicated slave in the cloud, for example on Amazon AWS? Hardware resources are [...]
Announcing Percona Server 5.1.66-14.2
Percona is glad to announce the release of Percona Server 5.1.66-14.2 on January 15th, 2013 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.1.66, including all the bug fixes in it, Percona Server 5.1.66-14.2 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 can [...]
Profiling MySQL Memory Usage With Valgrind Massif
There are times where you need to know exactly how much memory the mysqld server (or any other program) is using, where (i.e. for what function) it was allocated, how it got there (a backtrace, please!), and at what point in time the allocation happened. For example; you may have noticed a sharp memory increase [...]
How does MySQL Replication really work?
While we do have many blog posts on replication on our blog, such as on replication being single-threaded, on semi-synchronous replication or on estimating replication capacity, I don’t think we have one that covers the very basics of how MySQL replication really works on the high level. Or it’s been so long ago I can’t [...]
Announcing Percona Server 5.5.28-29.3
Percona is glad to announce the release of Percona Server 5.5.28-29.3 on January 8th, 2012 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.28, including all the bug fixes in it, Percona Server 5.5.28-29.3 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 [...]
Is there room for more MySQL IO Optimization?
I prefer to run MySQL with innodb_flush_method=O_DIRECT in most cases – it makes sure there is no overhead of double buffering and I can save the limited amount of file system cache I would normally have on database server for those things which need to be cached — system files, binary log, FRM files, MySQL [...]
Announcing Percona Server 5.5.28-29.2
Percona is glad to announce the release of Percona Server 5.5.28-29.2 on December 7th, 2012 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.28, including all the bug fixes in it, Percona Server 5.5.28-29.2 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 [...]
Replication of the NOW() function (also, time travel)
Notice the result of the NOW() function in the following query. The query was run on a real database server and I didn’t change the clock of the server or change anything in the database configuration settings.
1 2 3 4 5 6 7 | mysql> SELECT NOW(),SYSDATE(); +---------------------+---------------------+ | NOW() | SYSDATE() | +---------------------+---------------------+ | 1999-01-01 00:00:00 | 2012-11-29 05:50:03 | +---------------------+---------------------+ 1 row in set (0.00 sec) |
You may proceed to party like it is 1999. How can the NOW() function return a value [...]
Announcing Percona Playback 0.5
Percona is glad to announce the release of Percona Playback 0.5 on November 26th, 2012. Downloads are available from our download site and Percona Software Repositories. Percona Playback is a tool for replaying the load of one database server to another. Currently it can read queries from MySQL query-log and tcpdump files and run them [...]

