Codership team published beta2 of MySQL 5.5.15 with Galera replication
https://launchpad.net/codership-mysql
and we made port to Percona Server:

source code:
lp:~percona-dev/percona-server/percona-server-galera-5.5.15
binaries for RedHat/CentOS 6:
http://www.percona.com/downloads/TESTING/Galera/Percona-XtraDB-Galera-5.5.15.tar.gz

What difference between Percona Server+Galera and MySQL 5.5.15 ?
First of course, Percona Server+Galera is based on our XtraDB engine.
Second, we provide wsrep_sst_xtrabackup script, which allows to use Percona XtraBackup for node provisioning.
Percona Server+Galera is still on early stage, and we make it available so you can play it to gain some …

I am very happy to welcome Patrick Crews to the Percona development team. Patrick joins Percona at a very exciting time for the development team. We are getting regular releases of Percona Server and Percona Xtrabackup out the door, we have been heavily using the Jenkins continuous integration system to maintain and improve the quality of the products we ship and we just upgraded our documentation publishing platform for both Percona Server (5.1 and 5.5) and …

Percona is glad to announce the release of Percona XtraBackup 1.6.3 on 22 September, 2011 (Downloads are available here and from the Percona Software Repositories).

This release is purely composed of bug fixes and is the current stable release of Percona Xtrabackup.

If the innodb_file_per_table server option is being used and DDL operations, TRUNCATE TABLE, DROP/CREATE the_same_table or ALTER statements on InnoDB tables are executed while taking a backup, an upgrade to XtraBackup 1.6.3 is strongly recommended. Under this scenario, if the server version is prior to 5.5.11 in 5.5 series or prior to 5.1.49 in 5.1 series, a server upgrade is …

Daniel and I and the Percona release engineering team are proud to announce version 1.0.1 of Percona Toolkit. This toolkit is Percona’s suite of DBA and sysadmin productivity tools for MySQL. It is the successor to the popular Maatkit and Aspersa toolkits. Percona Toolkit is available for immediate download at percona.com/downloads/percona-toolkit/.

Helpful links:

• Reference Manual and Documentation
• Launchpad Project
• Bug Reports
• …

Codership team announced availability of MySQL/Galera 0.8.1, which is minor release, but actually it has bunch of improvements that makes Galera replication more user friendly (there are many bugs fixed, reported by me personally, what annoyed me a lot).

As part of my evaluation activity I ported MySQL/Galera 0.8.1 to Percona Server/Galera 0.8.1 and you can get source code on Launchpad.

I appreciate the fact that not everybody has fun from compiling source code (hint, hint for Drizzle developers), that is why I also made binaries for RHEL 6.1 / Oracle Linux 6.1
…

As you may know I closely follow Galera replication development, and right now I am evaluating how it performs in our benchmarks. Of course my closest interest is Percona Server, so I made port of Galera from MySQL/InnoDB-plugin to Percona Server 5.1.57. Right now it is only in source code https://code.launchpad.net/~vadim-tk/percona-server/percona-galera-5.1.57, but it brings couple good things:

• It is based on Percona Server with XtraDB, with all its performance and diagnostic improvements
• It contains scripts for xtrabackup node propagation, which provides minimal impact on the cluster when new node joins

You are welcome to try it, however it is not recommended to use in production, as …

As you may know, Kristian Nielsen made a fix for the Group Commit Problem which we many times wrote about. The fix came into MariaDB 5.3 and Mark Callaghan tested it recently . We ported this patch to Percona Server (it is not in the main branch yet), and here are the results of my testing of the new Group Commit in Percona Server 5.1.

As background information, the problem appears when you have strict durability and recover-ability requirements, that is innodb_flush_log_at_trx_commit=1, sync_binlog=1 and you do not have storage that provides fast syncs (i.e. you do not have a battery-backed cache on your RAID card). This scenario may also appear when being on battery and your RAID card dies, automatically switching from write-back to write-through cache mode.

We …

Percona is glad to announce the release of Percona Server 5.5.12-20.3 on June 9, 2011 (Downloads are available here and from the Percona Software Repositories).

Based on MySQL 5.5.12, Percona Server 5.5.12-20.3 is now the current stable release in the 5.5 series.

Other Changes

• The list of authors of the plugins used have been corrected. Bug Fixes:#723050 (Y. Kinoshita)

For more information, please see the following links:

• Downloads: Binary distribution,  …

Released on June 8, 2011 (Downloads are available here and from the Percona Software Repositories.

Percona Server 5.1.57-12.8 is now the current stable release in the 5.1 series. It is is based on MySQL 5.1.57.

Bug Fixes

• Fixed InnoDB I/O code so that the interrupted system calls are restarted if they are interrupted by a signal. InnoDB I/O code was not fully conforming to the standard on POSIX systems, causing a crash with an assertion failure when receiving a signal on pwrite(). Bug Fixed: LaunchPad: #764395 / MySQL bug #60788 (A. …

MySQL 5.5 and Percona Server 5.5 do not solve all scalability problems even for read only workloads. Workloads which got a lot of attention such as Sysbench and DBT2/TPC-C scale pretty well a they got a lot of attention, there can be other quite typical workloads however which do not scale that well. This is why it is important to test performance and scalability for your application on your hardware if you really want results most relevant for your situation.

In this example I spotted the query pattern responsible for large portion of the load in the application by aggregating query log with mk-query-digest. When I filtered out only queries of this pattern and got a simplified part of production workload which focuses only on one query but yet mimics real world values distribution.

The query looks something like this:

SELECT *  FROM table WHERE deleted = 0 AND group_id IN (62715996, 62716592, 62717660, …