Question
How to customize MySQL variables (e.g. max_allowed_packet, read_buffer_size or wait_timeout) on a Plesk server?
Answer
Note: Custom values must not exceed the limits defined by MySQL. For example, the highest value for max_allowed_packet is 1073741824 bytes (1024M) for wait_timeout - 31536000 seconds.
- Connect to the Plesk server via SSH.
 - 
Open the my.cnf file in a text editor. In this example, we are using the vi editor:
- on CentOS/RHEL-based distributions:
# vi /etc/my.cnf
 
- on Debian/Ubuntu-based distributions:
# vi /etc/mysql/my.cnf
 
 - on CentOS/RHEL-based distributions:
 - 
Add your custom variables under the
[mysqld]section. If the variable is also applicable to[client],[mysql]and[mysqldump]sections, add it there too.In this example, we are adding
max_allowed_packetandwait_timeoutdirectives:[mysqld]
wait_timeout = 31536000
max_allowed_packet = 1024M
...
[mysqldump]
max_allowed_packet = 1024M - 
Save the changes and close the file.
 - 
Restart the MySQL/MariaDB service:
# systemctl restart mysql || systemctl restart mariadb || systemctl restart mysqld
 
- Connect to Plesk server via RDP.
 - Open the file 
%plesk_dir%DatabasesMySQLmy.iniin a text editor. - 
Add your custom variables under the
[mysqld]section. If the variable is also applicable to[client]and[mysqldump]sections, add it there too.In this example, we are adding
max_allowed_packetandwait_timeout:[mysqld]
wait_timeout = 31536000
max_allowed_packet = 1024M
...
[mysqldump]
max_allowed_packet = 1024M - 
Save the changes and close the file.
 - 
Restart the MySQL/MariaDB service via Windows Services or Plesk Services Monitor.