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Percona Server 5.5.13-20.4 Stable Release

 | July 1, 2011 |  Posted In: MySQL


Percona is glad to announce the release of Percona Server 5.5.13-20.4 on July 1st, 2011 (Downloads are available here and from the Percona Software Repositories).

Based on MySQL 5.5.13, Percona Server Percona Server 5.5.13-20.4 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 5.5.13-20.4 milestone at Launchpad.


SHM Buffer Pool has been replaced with LRU Dump/Restore

The ”SHM” buffer pool patch, which provided the ability to use a shared memory segment for the buffer pool to enable faster server restarts, has been removed. Instead, we recommend using the LRU Dump/Restore patch which provides similar improvements in restart performance.

Replacement is due to SHM buffer pool both being very invasive and not widely used. Improved restart times are better provided by the much safer LRU D/R patch which has the advantage of also persisting across machine restarts.

The configuration variables for my.cnf have been kept for compatibility and warnings will be printed for the deprecated options (innodb_buffer_pool_shm_key and innodb_buffer_pool_shm_checksum) if used.

Instructions for disabling the SHM buffer pool can be found here.

Instructions on setting up LRU dump/restore can be found here.

Bug Fixes

  • On a high concurrency environment with compressed tables, users may experience crashes due to improper mutex handling inbuf_page_get_zip(). Bug Fix: #802348 (Y. Kinoshita).
  • XtraDB crashed when importing big tables (e.g. 350G) using the Expand Table Import feature due to a timeout. Bug Fix: #684829 (Y. Kinoshita).
  • Partitioning adaptive hash index may leave to a hangup of the server in some scenarios. Bug Fix: #791030 (Y. Kinoshita).
  • Statistics gathering for each record’s update. Bug #791092 (Y. Kinoshita)

Other Changes

  • Improvements and fixes on platform-specific distribution: #737947

For more information, please see the following links:

Stewart Smith

Stewart Smith has a deep background in database internals including MySQL, MySQL Cluster, Drizzle, InnoDB and HailDB. he is also one of the founding core developers of the Drizzle database server. He served at Percona from 2011-2014. He is a former Percona employee.


  • When I compile Percona 5.5 on CentOS5.5, I got the error:query_response_time.cc:180: undefined reference to `__sync_bool_compare_and_swap_4′ . But mysql has no this error. Can you help me out?

  • Your repository server seems pretty slow some times, I’m getting 15.6kB/s from Germany (100mbit/s connection here). Are there any mirrors?

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