Save energy by OS-driven DRAM refresh:

Had the same idea… they’ve been faster :)

Recent Tips and News on Java, Java EE 6, GlassFish & more :

OK, to begin with, I'd really like to try MySQL Cluster as a Key-Value Store. Yes, I have already recognized that MySQL Cluster stores variable length data in fixed length format. And someone should think about how good an idea this really is, in my mind it's just as mindbogglingly efficient, modern and start as storing data on punched cards. Which I assume how the MySQL Cluster sourcecode is managed.

yes, I really dislike the idea of fixed length strings, and more on this later. But think now, I have 2 fields defined as VARCHAR(256) and this is a Web application, then how much space will be allocated on disk for MySQL Clsuter? As many bytes are there are in the string r 256 bytes? Neither actually, this is a web-app, and I know it comes as a surprise to some of you, but Unicode is here to stay, and UTF-8 is way to go. And MySQL assumes that no one will use more than a 3-byte Unicode character (which is an incorrect assummpion, but I …

Since the new MySQL Pacemaker resource agent supporting PRM is now included in version 3.9.3 of the official Pacemaker resource agents package and things have stabilized a bit, I have been able to write some documentation. I wrote a first draft of the PRM documentation that is likely far from perfect, but I hope it will be useful and improve rapidly. The PRM documentation is available here. Comments and suggestions are welcome but please use the linux-ha or the pacemaker mailing lists instead of replying to the blog post directly.

The binlog sync contention was a problem from a long date in MySQL.. Well, it was less visible few years ago until MySQL performance was quite limited even without binlog enabled ;-)) However, with all latest performance improvement came with MySQL 5.5 and now with 5.6, it became unacceptable to see all these excellent goodies simply killed once a user enabling binlog..

Good news -- the latest MySQL 5.6 labs release is coming with freshly released Binlog Group Commit which is greatly solving this issue. You may find all details about in the Mat's article, while my intention in this post is just to extend little bit already presented benchmark results..

Well, the true performance problem with MySQL binlog is coming not really when it's enabled, but since the "sync_binlog" is set to 1 (means flush binlog to disk …

This article describes how I tuned MariaDB to give the best write throughput with SSD based storage.

When you have a write-heavy application writing into InnoDB, you will probably experience the InnoDB Checkpoint Blues. The effect manifests as stalls – short periods of time where the troughput falls to zero and I/O activity goes crazy. The phenomenon is well known and described i.e. here. More background about checkpointing can be found …

A few days ago MariaDB, MySQL and Percona all three released new versions of the 5.5 server. So I decided it’s time to run sysbench once more and compare the OLTP performance. The test candidates are:

• MariaDB-5.5.24, using either XtraDB (default) or InnoDB
• MySQL-5.5.25
• Percona Server 5.5.24-26.0

For the benchmarks I used our trusty old pitbull machine which has 24 cpu cores, 24G of RAM and a nice RAID-0 composed of 3 SAS SSD.

The benchmark was sysbench-0.5 multi-table OLTP, using 8 tables with total 10G of data. InnoDB buffer pool was 16G, InnoDB log group capacity 4G (the maximum for MySQL). The mysqld process was constrained to 16 cores, sysbench to the other 8.

The only nonstandard tuning was for I/O scalability: innodb_io_capacity = 20000 and innodb_flush_neighbor_pages = none (for Percona Server and MariaDB/XtraDB). See …

This article describes how I tuned MariaDB to give the best write throughput with SSD based storage.

When you have a write-heavy application writing into InnoDB, you will probably experience the InnoDB Checkpoint Blues. The effect manifests as stalls – short periods of time where the troughput falls to zero and I/O activity goes crazy. The phenomenon is well known and described i.e. here. More background about checkpointing can be found …

The week started with MySQL Innovation Day , which included some great presentations for the Oracle engineers and the MySQL community.

Today though is MySQL Day at SELF and it is packed with top MySQL presentations from Oracle and the MySQL Community including: Sheeri Cabral, Ronald Bradford, Peter Zaitsev, Baron Schwartz, Jeff Mace, Charles Bell, Craig Sylvester,  David Stokes and even myself.

If your in the area we hope to see you !

I am happy to announce next version Percona XtraDB Cluster 5.5.24, which is mostly jump to the current version of Percona Server.

It includes an important bug fix:

• table with no PK but still having UK, can cause crash in slave using PA

Binaries are available from downloads area or from our repositories.

For this release we provide binaries for Ubuntu 12.04.

If you want to know more how to migrate to XtraDB Cluster, you can check our recent webinar Migrating To Percona XtraDB Cluster.

This is an General Availability release. We did our best to eliminate bugs and problems during alpha and …