MySQL multi-instance installation boot auto-start service configuration process

[root@clq ~]# mkdir /opt/data/{3306,3307,3308} -p
[root@clq ~]# chown mysql.mysql /opt/data/*

[root@192 ~]# mysqld --initialize --datadir=/opt/data/3306 --user=mysql
[root@192 ~]# mysqld --initialize --datadir=/opt/data/3307 --user=mysql
[root@192 ~]# mysqld --initialize --datadir=/opt/data/3308 --user=mysql
#Save 3 mysql passwords respectively [root@192 ~]# echo 'wxa+r_N6ooYu' > 3306
[root@192 ~]# echo 'faiuehfaowh' > 3307
[root@192 ~]# echo 'fuahfu' > 3308

[root@clq ~]# yum -y install perl

[root@clq ~]# dnf whatprovides libncurses.so.5
ncurses-compat-libs-6.1-7.20180224.el8.i686 : Ncurses compatibility libraries #See which package provides the repository:
@System matches source: Provided by: libncurses.so.5
[root@clq ~]# dnf -y install ncurses-compat-libs (compatibility library)

[root@192 ~]# cat /etc/my.cnf 
[mysqld_multi]
mysqld = /usr/local/mysql/bin/mysqld_safe #Safe directory mysqladmin = /usr/local/mysql/bin/mysqladmin #Administrator login directory [mysqld3306]
datadir = /opt/data/3306
port = 3306
socket = /tmp/mysql3306.sock
pid-file = /opt/data/3306/mysql3306.pid
log-error = /var/log/3306.log
[mysqld3307] #Must be mysqld3307, not mysql3307
datadir = /opt/data/3307
port = 3307
socket = /tmp/mysql3307.sock
pid-file = /opt/data/3307/mysql3307.pid
log-error = /var/log/3307.log
[mysqld3308]               
datadir = /opt/data/3308
port = 3308
socket = /tmp/mysql3308.sock
pid-file = /opt/data/3308/mysql3308.pid
log-error = /var/log/3308.log

#Copy the mysqld_multi service script to /etc/init.d/[root@mysql ~]# cp /usr/local/mysql/support-files/mysqld_multi.server /etc/init.d/mysqld_multi
#Modify the script. When the system script is started, it will be reloaded in the new terminal. Adding this line will find mysqld_multi under bindir
basedir=/usr/local/mysql
bindir=/usr/local/mysql/bin
export PATH=$bindir:$PATH
systemctl daemon-reload system reloading service is enabled:
[root@mysql ~]# service mysqld_multi start 3306
[root@mysql ~]# service mysqld_multi start 3307
[root@mysql ~]# service mysqld_multi start 3308
Self-start:
[root@mysql ~]# chkconfig mysqld_multi on
[root@mysql ~]#reboot
[root@mysql ~]# ss -antl
State Recv-Q Send-Q Local Address:Port Peer Address:Port Process                               
LISTEN 0 80 *:3306 *:*                          
LISTEN 0 80 *:3307 *:*                          
LISTEN 0 80 *:3308 *:*