fwiw, mysqld honors the limits as indicated in /etc/security/limits.conf but ignores its own limits:
root@trusty:/root# service mysql restart
* Stopping Percona Server 5.7.18-14
...
* Percona Server 5.7.18-14 is stopped
* Re-starting Percona Server 5.7.18-14
..
* Percona Server 5.7.18-14 is started
root@trusty:/root#
root@trusty:/root# grep nofile /etc/security/limits.conf
# - nofile - max number of open files
root soft nofile 1048576
root hard nofile 1048576
mysql soft nofile 1048576
mysql hard nofile 1048576
root@trusty:/root#
root@trusty:/root# mysql -uroot -p -e "show global variables like '%open_files%'";
Enter password:
+-------------------+---------+
| Variable_name | Value |
+-------------------+---------+
| innodb_open_files | 2000 |
| open_files_limit | 1048576 | <---
+-------------------+---------+
root@trusty:/root# grep -B1 open /etc/my.cnf
[mysqld]
open-files-limit=1024000
--
[mysqld_safe]
open-files-limit=1024000
root@trusty:/root#
fwiw, mysqld honors the limits as indicated in /etc/security/ limits. conf but ignores its own limits:
root@trusty:/root# service mysql restart limits. conf ------- ------+ ------- --+ ------- ------+ ------- --+ ------- ------+ ------- --+ limit=1024000 limit=1024000
* Stopping Percona Server 5.7.18-14
...
* Percona Server 5.7.18-14 is stopped
* Re-starting Percona Server 5.7.18-14
..
* Percona Server 5.7.18-14 is started
root@trusty:/root#
root@trusty:/root# grep nofile /etc/security/
# - nofile - max number of open files
root soft nofile 1048576
root hard nofile 1048576
mysql soft nofile 1048576
mysql hard nofile 1048576
root@trusty:/root#
root@trusty:/root# mysql -uroot -p -e "show global variables like '%open_files%'";
Enter password:
+------
| Variable_name | Value |
+------
| innodb_open_files | 2000 |
| open_files_limit | 1048576 | <---
+------
root@trusty:/root# grep -B1 open /etc/my.cnf
[mysqld]
open-files-
--
[mysqld_safe]
open-files-
root@trusty:/root#