Change mysql Directory of percona 8 Cluster

Warning

Only change the config file on one server at a time, if you change it on all of them your cluster will break change one, sync, then move onto the next

Introducrtion

Percona cluster has a ton of advantages, least of which is the ability to rebuild and change a node then add it back, and all data is synced back.

We will go through the steps of changing the data directory and pid file I needed this for the way we monitor filesystems and pid's

Disable plugins

It will reinitialize the database, so you will need to disable your plugins like audit_log_policy and validate_password_policy

Note

change the config file to your config file location and name

sed -i 's/audit_log_policy/#audit_log_policy/g' /etc/my.cnf.d/db03.my3311.cnf
sed -i 's/validate_password_policy/#validate_password_policy/g' /etc/my.cnf.d/db03.my3311.cnf

Change config

Change you config as needed. In my case i wanted to change the database directories, pid and sock file names and locations

server-id=2
port                          = 3311
datadir                       = /data/3311/mysql
socket                        = /data/3311/mysql/mysql.sock
log-error                     = /var/log/mysqld_3311.log
pid-file                      = /data/3311/mysql/mysqld.pid
user                          = mysql

TO

[mysqld]
server-id=3
port                          = 3311
datadir                       = /data/3311/mysql11
socket                        = /data/3311/mysql11/mysql11.sock
log-error                     = /var/log/mysqld_3311.log
pid-file                      = /data/3311/mysql11/mysqld11.pid
user                          = mysql

Apply

stop your database

systemctl stop mysql

Now delete the database

rm -rf /data/3311/mysql

Start mysql, which will sync from one of the other nodes

systemctl start mysql

Once it starts, your database will be syned, but now you will need to re enable all your plugins

Enable Plugins

sed -i 's/#audit_log_policy/audit_log_policy/g' /etc/my.cnf.d/db03.my3311.cnf
sed -i 's/#validate_password_policy/validate_password_policy/g' /etc/my.cnf.d/db03.my3311.cnf

Restart to apply:

systemctl restart mysql

Apply to the rest of the cluster

Re run the steps on each cluster