Based on the upstream http://bugs.mysql.com/bug.php?id=66868 status and last comment, this is a confirmed bug in 5.1.x and 5.5.x, while in 5.6.x the problem is fixed in upstream.
** Also affects: mysql-server via http://bugs.mysql.com/bug.php?id=66868 Importance: Unknown Status: Unknown ** Also affects: percona-server/5.1 Importance: Undecided Status: New ** Also affects: percona-server/5.5 Importance: Undecided Status: New ** Also affects: percona-server/5.6 Importance: Undecided Status: New ** Changed in: percona-server/5.1 Status: New => Confirmed ** Changed in: percona-server/5.5 Status: New => Confirmed ** Changed in: percona-server/5.6 Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Server/Client Support Team, which is subscribed to MySQL. Matching subscriptions: Ubuntu Server/Client Support Team https://bugs.launchpad.net/bugs/1057087 Title: slave IO_THREAD blocks replication - sql thread To manage notifications about this bug go to: https://bugs.launchpad.net/mysql-server/+bug/1057087/+subscriptions -- Mailing list: https://launchpad.net/~enterprise-support Post to : [email protected] Unsubscribe : https://launchpad.net/~enterprise-support More help : https://help.launchpad.net/ListHelp

