I had the chance to work on an interesting case last week, and I thought I’d share what I think is a little known goodie from Percona Toolkit for MySQL called pt-query-digest. One customer was suffering from periods of high load on their database server, leading to degraded application performance, and sometimes even short moments [...]
Why do we care about MySQL Performance at High Concurrency?
In many MySQL Benchmarks we can see performance compared with rather high level of concurrency. In some cases reaching 4,000 or more concurrent threads which hammer databases as quickly as possible resulting in hundreds or even thousands concurrently active queries. The question is how common is it in production ? The typical metrics to use [...]
Percona Welcomes MySQL 5.6!
MySQL 5.6 was made generally available as a production-ready solution earlier this month. This release comes about 2 years after MySQL 5.5 was released, but MySQL 5.6 contains improvements started long before that – for example, work on the Innodb Full Text Search project was started over 6 years ago, in addition with many optimizer [...]
Replication checksums in MySQL 5.6
MySQL 5.6 has an impressive list of improvements. Among them, replication checksums caught my attention as it seems that many people misunderstand the real added value of this new feature. I heard people think that with replication checksums, data integrity between the master and its replicas is now enforced. As we’ll see, it’s not that [...]
How to create/restore a slave using GTID replication in MySQL 5.6
MySQL 5.6 is GA! Now we have new things to play with and in my personal opinion the most interesting one is the new Global Transaction ID (GTID) support in replication. This post is not an explanation of what is GTID and how it works internally because there are many documents about that: http://dev.mysql.com/doc/refman/5.6/en/replication-gtids-concepts.html One [...]
Read/Write Splitting with PHP Webinar Questions Followup
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 [...]
Thank you for joining us at Percona Live, NYC 2012
Over 200 attendees attended last week’s Percona Live NY event. This year we structured event different than in 2011 with Tutorial Day allowing for in-depth 3 hour presentations for those looking to dive deep into specific topics. We also added an Expo Hall which allowed a lot of MySQL Ecosystem participant to meet their prospective [...]
Logging Foreign Key errors
In the last blog post I wrote about how to log deadlock errors using Percona Toolkit. Foreign key errors have the same problems. InnoDB only logs the last error in the output of SHOW ENGINE INNODB STATUS, so we need another similar tool in order to have historical data. pt-fk-error-logger This is a tool very [...]
The Math of Automated Failover
There are number of people recently blogging about MySQL automated failover, based on production incident which GitHub disclosed. Here is my take on it. When we look at systems providing high availability we can identify 2 cases of system breaking down. First is when the system itself has a bug or limitations which does not [...]
Identifying the load with the help of pt-query-digest and Percona Server
Overview Profiling, analyzing and then fixing queries is likely the most oft-repeated part of a job of a DBA and one that keeps evolving, as new features are added to the application new queries pop up that need to be analyzed and fixed. And there are not too many tools out there that can make [...]

