July 24, 2014

MySQL 4 to MySQL 5 Upgrade performance regressions

This week I already had two serious performance regression cases when upgrading from MySQL 4.0 and 4.1 to MySQL 5.0. By serious I mean several times performance difference not just 5-10% you often see for simple queries due to generally fatter code. The problem in both cases was MySQL 5.0 broken group commit bug. First […]

MySQL Replication and Slow Queries

I just filed a bug regarding slow queries executed by replication thread are not being logged to the slow query log. This is not a big deal but it is ugly little gotcha which I think few people know about. It is especially bad if you’re using tools to analyze slow query log to find […]

Percona Server 5.6.17-65.0 is now available

Percona is glad to announce the release of Percona Server 5.6.17-65.0 on May 6th, 2014. Downloads are available here and from the Percona Software Repositories. Based on MySQL 5.6.17, including all the bug fixes in it, Percona Server 5.6.17-65.0 is the current GA release in the Percona Server 5.6 series. All of Percona’s software is […]

Percona Server 5.5.37-35.0 is now available

Percona is glad to announce the release of Percona Server 5.5.37-35.0 on May 6th, 2014 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.37, including all the bug fixes in it, Percona Server 5.5.37-35.0 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 […]

Percona Testing: Innodb crash / recovery tests available

Not everyone may know this, but there are precious few innodb crash recovery tests available. Some folks have noticed this and asked for something to be done about it, but unfortunately, no tests have been created for the main MySQL branch. The MySQL at Facebook branch has a number of tests that are quite interesting.  […]

Drop table performance

There have been recent discussions about DROP TABLE performance in InnoDB. (You can refer to Peter’s post http://www.mysqlperformanceblog.com/2011/02/03/performance-problem-with-innodb-and-drop-table/ and these bug reports: http://bugs.mysql.com/bug.php?id=51325 and http://bugs.mysql.com/bug.php?id=56332.) It may not sound that serious, but if your workload often uses DROP TABLE and you have a big buffer pool, it may be a significant issue. This can get […]

My “hot” list for next InnoDB features

Many InnoDB scalability problems seem fixed in InnoDB-plugin-1.0.3 and I expect InnoDB-plugin will run fine on 16-24 cores boxes for many workloads. And now it is time to look on systems with 32GB+ of RAM which are not rare nowadays. Working with real customer systems I have wish-list of features I would like to see […]

Testing InnoDB “Barracuda” format with compression

New features of InnoDB – compression format and fast index creation sound so promising so I spent some time to research time and sizes on data we have on our production. The schema of one of shards is

Heikki Tuuri answers to Innodb questions, Part II

I now got answers to the second portions of the questions you asked Heikki. If you have not seen the first part it can be found here. Same as during last time I will provide my comments for some of the answers under PZ and will use HT for original Heikkis answer. Q26: You also […]

InnoDB benchmarks

There was several changes in InnoDB to fix scalabilty problems, so I ran benchmark to check new results and also compare overall performance of InnoDB in 5.0 and 5.1 before and after fixes. Problems in InnoDB that were fixed: Thread trashing issues with count of theads 100+. In this case performance of InnoDB degraded dramatically. […]