.. rn:: 5.5.21-25.0

==============================
 |Percona Server| 5.5.21-25.0
==============================

Percona is glad to announce the release of |Percona Server| 5.5.21-25.0 on March 20, 2012 (Downloads are available `here <http://www.percona.com/downloads/Percona-Server-5.5/Percona-Server-5.5.21-25.0/>`_ and from the `Percona Software Repositories <http://www.percona.com/docs/wiki/repositories:start>`_).

Based on `MySQL 5.5.21 <http://dev.mysql.com/doc/refman/5.5/en/news-5-5-21.html>`_, including all the bug fixes in it, |Percona Server| 5.5.21-25.0 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 can be found in the `5.5.21-25.0 milestone at Launchpad <https://launchpad.net/percona-server/+milestone/5.5.21-25.0>`_.

Improvements to the XtraDB’s sync flush algorithm made in |Percona Server| `5.5.19-24.0 <http://www.percona.com/downloads/Percona-Server-5.5/Percona-Server-5.5.19-24.0/>`_ have been reverted because of the performance issues on SSDs (*Laurynas Biveinis*). 

New Features
============

Slow query logging features have been expanded by adding new variable :variable:`log_slow_rate_type`. It now provides option to specify the query sampling being taken. If the variable is set up to "query", sampling is done on per query basics instead of session, which is the default (*Oleg Tsarev*).

Bug Fixes
=========

  * Fixed MySQL bug `#49336 <http://bugs.mysql.com/bug.php?id=49336>`_, mysqlbinlog couldn't handle stdin when "|" used. Bug fixed: :bug:`933969` (*Sergei Glushchenko*).
  * Fixed MySQL bugs: `#64432 <http://bugs.mysql.com/bug.php?id=64432>`_ and `#54330 <http://bugs.mysql.com/bug.php?id=54330>`_, broken fast index creation. Bug fixed: :bug:`939485` (*Laurynas Biveinis*).
