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