rotating mysql slow query log

Question

My server's MySQL slow query log is growing day by day (37 MB now) so I want to rotate it. If I move current log file to another folder then will MySQL automatically create another log file? Think of it like I am deleting current log file, so will MySQL automatically create a new one when another slow query comes?

Thanks

Answer 1

you simply cant use logrotate to do that , you will have to first change the file name in my.cnf and than do what ever wants to do.reload the mysql.

if you want the logrotate way , you will have to disable the slow query log for that time.

The logrotate thing was suggested by percona team and works for me.

/var/mysql/slow_query.log {
    nocompress
    create 660 mysql mysql
    size 1G
    dateext
    missingok
    notifempty
    sharedscripts
    postrotate
       /usr/local/bin/mysql -e 'select @@global.long_query_time into @lqt_save; set global long_query_time=2000; select sleep(2); FLUSH LOGS; select sleep(2); set global long_query_time=@lqt_save;'
    endscript
    rotate 150
}

Answer 2

You can use logrotate script to periodically rotate MySQL logs, and possibly keep a limited number of previous logs (to save space). You can configure it with any schedule you like.

Personally, I found it easy to configure using Webmin GUI

Answer 3

You can setup a daily cron which will be ziping and emptying the logfile:

zip /tmp/$(date +%Y-%m-%d)-slow-query-log.zip /var/lib/mysql/slow-queries.log
cat /dev/null > /var/lib/mysql/slow-queries.log

Of course, if your slow query log has so much content logged every day you (or someone else) ought to investigate and fix the bad queries :)