October 25, 2014

How innodb_open_files affects performance

Recently I looked at table_cache sizing which showed larger table cache does not always provides the best performance. So I decided to look at yet another similar variable – innodb_open_files which defines how many files Innodb will keep open while working in innodb_file_per_table mode. Unlike MyISAM Innodb does not have to keep open file descriptor […]

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 […]

What is the longest part of Innodb Recovery Process ?

In MySQL 4.1 and above the longest part of recovery after crash for Innodb tables could be UNDO stage – it was happening in foreground and was basically unbound – if you have large enough transaction which needed to be undone this could take long hours. REDO stage on other hand always could be regulated […]

Innodb Performance Optimization Basics

Note: There is an updated post on this topic here. Interviewing people for our Job Openings I like to ask them a basic question – if you have a server with 16GB of RAM which will be dedicated for MySQL with large Innodb database using typical Web workload what settings you would adjust and interestingly […]

Opening Tables scalability

I was restarting MySQL on box with 50.000 of Innodb tables and again it took couple of hours to reach decent performance because of “Opening Tables” stage was taking long. Part of the problem is Innodb is updating stats on each table open which is possibly expensive operation, but really it is only great test […]

How to recover an orphaned .ibd file with MySQL 5.6

A few years ago Yves Trudeau and Aleksandr Kuzminsky wrote posts about different ways for recovering orphaned .ibd files: Connecting orphaned .ibd files A recovery trivia or how to recover from a lost ibdata1 file Today I want to show you how to do that in more easy and quick way. In my example I’ll […]

Advanced MySQL Query Tuning: Webinar followup Q&A

Thanks to all who attended my “MySQL Query Tuning” webinar on July 24.  If you missed it, you can you can download the slides and also watch the recorded video. Thank you for the excellent questions after the webinar as well. Query tuning is a big topic and, due to the limited time, I had […]

Percona XtraBackup 2.1.0 ‘release candidate’ for MySQL available for download

Percona is glad to announce the release of Percona XtraBackup 2.1.0-rc1 on May 7, 2013. Downloads are available from our download site here. For this RC release, we will not be making APT and YUM repositories available, just base deb and RPM packages This is an Release Candidate quality release and is not intended for […]

Percona XtraBackup 2.0.7 for MySQL available for download

Percona is glad to announce the release of Percona XtraBackup 2.0.7 for MySQL on May 6, 2013. Downloads are available from our download site here and Percona Software Repositories. Percona XtraBackup is the world’s only open-source, free MySQL hot backup software that performs non-blocking backups for InnoDB and XtraDB databases. This release is the current GA (Generally Available) […]

MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark

So far most of the benchmarks posted about MySQL 5.6 use the sysbench OLTP workload.  I wanted to test a set of queries which, unlike sysbench, utilize joins.  I also wanted an easily reproducible set of data which is more rich than the simple sysbench table.  The Star Schema Benchmark (SSB) seems ideal for this. […]