清理过期django.contrib.会议&#在一个巨大的MySQL InnoDB表中

Posted 2021-02-24

While django provides the django_admin.py cleanup script, if sessions get out of control sometimes you have to go lower level to get everything cleaned up. If the problem gets out of hand and you hit the resource limits of the machine, it is very difficult to get anything done in the database.

Attached is SQL code which was used to cleanup 27GB of expired session data in 3h. Run it like this to make sure it runs to completion:

`nohup mysql --user=username --password=password --host=hostname database < delete_expired_sessions.sql`

nohup causes the script to run detached from a terminal, so if your session gets disconnected it will keep running.

p.s.
An alternative approach is to launch this command from the shell:

DELETE FROM django_session WHERE expire_date < NOW();

or

DELETE FROM django_session WHERE expire_date < "2011-12-10 00:00:00";

DROP TABLE IF EXISTS `django_session_cleaned`;
CREATE TABLE `django_session_cleaned` (
  `session_key` varchar(40) NOT NULL,
  `session_data` longtext NOT NULL,
  `expire_date` datetime NOT NULL,
  PRIMARY KEY  (`session_key`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
 
INSERT INTO `django_session_cleaned` SELECT * FROM `django_session` WHERE `expire_date` > CURRENT_TIMESTAMP;
 
RENAME TABLE `django_session` TO `django_session_old_master`, `django_session_cleaned` TO `django_session`;
 
DROP TABLE `django_session_old_master`;