MySQL open files limit

Question

This question is similar to set open_files_limit, but there was no good answer.

I need to increase my table_open_cache, but first I need to increase the open_files_limit. I set the option in /etc/mysql/my.cnf:

open-files-limit = 8192

This worked fine in my previous install (Ubuntu 8.04), but now in Ubuntu 10.04, when I start the server up, open_files_limit is reported to be 1710. That seems like a pretty random number for the limit to be clipped to.

Anyway, I tried getting around it by adding a line like this in /etc/security/limits.conf:

mysql   hard   nofile   8192

I also tried adding this to the pre-start script in mysql's upstart config (/etc/init/mysql.conf):

ulimit -n 8192

Obviously neither of those things worked. So where is the hoop that has been added between Ubuntu 8.04 and 10.04 through which I must jump in order to actually increase the open files limit?

Solution

Solved it - there are no extra hoops, it's just the mysql config that lied! I had put the open-files-limit line in the [mysqld_safe] section, but it seems that section is no longer used. Moving all config options to [mysqld]...

Comments

[Giovanni Toraldo]

Seems that mysqld_safe is not needed anymore in Ubuntu, probably due to upstart introduction.