Percona Server for MySQL 5.6.27-75.0¶

Percona is glad to announce the release of Percona Server for MySQL 5.6.27-75.0 on November 5th, 2015 (Downloads are available here and from the Percona Software Repositories).

Based on MySQL 5.6.27, including all the bug fixes in it, Percona Server for MySQL 5.6.27-75.0 is the current GA release in the Percona Server for MySQL 5.6 series. All of Percona‘s software is open-source and free, all the details of the release can be found in the 5.6.27-75.0 milestone at Launchpad.

New Features¶

Percona Server for MySQL is now available for Ubuntu 15.10 (Wily).

TokuDB MTR tests have been integrated into Percona Server for MySQL.

Linux thread ID is now available in the PROCESSLIST table.

Percona Server for MySQL has now re-enabled savepoints in triggers and stored functions.

Variables innodb_buffer_pool_populate and numa_interleave have been mapped to the upstream implementation of the new innodb_numa_interleave option.

Bugs Fixed¶

Fixed transactional inconsistency with rollback in TokuDB. Rolling back a large transaction with many inserts/updates/deletes could result in some of the changes being committed rather than rolled back. Bug fixed #1512455.

Variable tokudb_backup_exclude was not excluding files correctly. Bug fixed #1512457.

TokuDB could crash under load if transaction-isolation level READ-COMMITTED was used. Bug fixed #1501633.

TokuDB thread pool names were missing in the SHOW ENGINE tokudb STATUS which caused duplicate entries. Bug fixed #1512452.

Manipulating the innodb_track_redo_log_now variable dynamically would crash the server if it was started without innodb_track_changed_pages enabled. This variable is available on debug builds only. Bug fixed #1368530.

If the user had duplicate pid-file options in config files when running yum upgrade, the upgrade would stop with error because it would think it found the duplicate pid while it was the same pid specified twice. Bug fixed #1454917.

On some filesystems server would not start if XtraDB changed page tracking feature was enabled and innodb_flush_method variable was set to O_DIRECT. Bugs fixed #1500720 and #1498891.

When User Statistics are enabled, executing any statement of the SHOW family with non-empty result, would bump USER_STATISTICS ROWS_FETCHED column values erroneously. Bug fixed #1510953.

A write operation with innodb_fake_changes enabled could cause a server assertion if it followed the pessimistic B-tree update path internally. Bug fixed #1192898.

An online DDL operation could have caused server crash with fake changes enabled. Bug fixed #1226532.

Fixed the conflicting meta packages between 5.1, 5.5, and 5.6 release series in Debian and Ubuntu distributions. percona-server-server and percona-server-client meta packages now point to the latest 5.6 release. Bug fixed #1292517.

INNODB_CHANGED_PAGES table was unavailable with non-default innodb_data_home_dir setting if the variable had a trailing slash. Bug fixed #1364315.

Changing innodb_fake_changes variable value in the middle of a transaction would have an immediate effect, that is, making part of the transaction run with fake changes enabled and the rest with fake changes disabled, resulting in a broken transaction. Fixed by making any innodb_fake_changes value changes becoming effective at the start of the next transaction instead of the next statement. Bug fixed #1395579.

UPDATE statement could crash the server with Support for Fake Changes enabled. Bug fixed #1395706.

Startup would fail due to a small hard-coded timeout value in the init script for the pid file to appear. This has been fixed by creating default file for Debian init script timeout parameters in etc/default/mysql. Bug fixed #1434022.

CMakeLists.txt for tokudb-backup-plugin was missing Valgrind dependency. Bug fixed #1494283.

Percona Server for MySQL would fail to install on CentOS 7 if mariadb-devel package was already installed. Bug fixed #1499721.

Fixed suboptimal Support for Fake Changes handling in online ALTER storage engine API. Bug fixed #1204422.

The upstream bug #76627 was not fixed for the ALL_O_DIRECT case. Bug fixed #1500741.

Fixed multiple TokuDB clang build issues. Bug fixed #1512449.