Configuring multiple instances of MySQL under Linux

Document directory

One . MySQL install

Two . Linux The configuration MySQL Multiple instances

• 2.1 Create the relevant directory and click OK
• 2.2 Modify the configuration file
• 2.3 Initialize and start the specified instance
• 2.4 Change password and open remote connection
• 2.5 Remote connection test
• 2.6 Multi instance start / stop scripts

One . MySQL install

MySQL Please refer to this blog for installation :

linux Lower installation MySQL5.7 And summarize the problems encountered

Two . Linux The configuration MySQL Multiple instances

Be careful : This part needs to be in ( One ) Based on

My multi instance directory is planned as follows :

Path action	Absolute position
mysql The installation path	/opt/modules/mysql
Each instance data directory	/opt/modules/mysql/data/{port}
Each instance log file	/opt/modules/mysql/logs/{port}/error.log
Generated at runtime pid file	/opt/modules/mysql/run/{port}/mysqld.pid
socket file	/var/lib/mysql/{port}/mysql.sock
Configuration files for each instance	/etc/mysql/{port}/my.cnf

2.1 Create the relevant directory and click OK

#  Here we use 3308 An example of a port number is , For example, configure other port numbers , Just change the port number in the command 
mkdir -p /opt/modules/mysql/data/3308
mkdir -p /opt/modules/mysql/run/3308
mkdir -p /opt/modules/mysql/logs/3308
touch /opt/modules/mysql/logs/3308/error.log
mkdir -p /var/lib/mysql/3308
chown -R mysql:mysql /var/lib/mysql
chown -R mysql:mysql /opt/modules/mysql
chmod -R 755 /opt/modules/mysql
mkdir -p /etc/mysql/3308

2.2 Modify the configuration file

vi /etc/mysql/3308/my.cnf

#3308 To configure , Be careful : Different instances only need to add the 3308 Replace it 

[mysqld]
datadir=/opt/modules/mysql/data/3308
port=3308
socket=/var/lib/mysql/3308/mysql.sock
basedir=/opt/modules/mysql
server-id=3308
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
max_connections=400
innodb_file_per_table=64
lower_case_table_names=1
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mariadb according to the
# instructions in http://fedoraproject.org/wiki/Systemd

[mysqld_safe]

log-error=/opt/modules/mysql/logs/3308/error.log
pid-file=/opt/modules/mysql/run/3308/mysqld.pid
[client]
port=3308
socket=/var/lib/mysql/3308/mysql.sock

2.3 Initialize and start the specified instance

#  initialization   Here you need to remember the last string output by the command , It as a MySQL Initial password for login   stay MySQL Install under directory bin Directory execution 
./mysqld --initialize --user=mysql --datadir=/opt/modules/mysql/data/3308 --basedir=/opt/modules/mysql
#  start-up MySQL  You need to specify the startup configuration file 
nohup /bin/sh /opt/modules/mysql/bin/mysqld_safe --defaults-file=/etc/mysql/3308/my.cnf --user=mysql &

2.4 Change password and open remote connection

#  Because here we are not by default 3306 Port boot , So you need to specify socket file 
#  The password entered is... Above mysql The last string output from the initialization command 
mysql -uroot -p -S /var/lib/mysql/3308/mysql.sock

#  Set the password 
mysql> set password for root@localhost = password('yourpassword');

#  Open remote connection 
mysql> use mysql;
mysql> update user set user.Host='%' where user.User='root';
mysql> flush privileges;

2.5 Remote connection test

Use SQLyog Test remote connection , make new connection
Enter the connection information , And port number

Click test connection :

You can see , The connection is normal ,Linux The configuration mysql Multiple instances succeeded

2.6 Multi instance start / stop scripts

When we deploy multiple servers on the same server MySQL When an instance , Multiple MySQL The maintenance of instances can become very complex
Based on the above, we are right to MySQL Directory planning , We can provide a unified start stop script maintenance for these instances
( Pass in the port number as a parameter to distinguish different MySQL example )

vim /opt/modules/mysql/bin/mysql_instance.sh

#!/bin/bash

# MySQL Multi instance unified start / stop script   Parameters 1:  Carry out orders (start|stop|restart)  Parameters 2: Port number ( Start and stop the corresponding instance through the port number )
# Parameters 3: mysql user name , Parameters 4: mysql password 


port=$2
mysql_user=$3
mysql_pwd=$4
cmd_path="/opt/modules/mysql/bin"
mysql_sock="/var/lib/mysql/${port}/mysql.sock"

#startup function
function_start_mysql(){
    
	if [ ! -e "$mysql_sock" ];then
		printf "Starting Mysql...\n"
		/bin/sh	${cmd_path}/mysqld_safe --defaults-file=/etc/mysql/${port}/my.cnf 2>&1 >/dev/null &    # Start command 
	else
		printf "Mysql is running...\n"
	exit
	fi
}

#stop function
function_stop_mysql(){
    
	if [ ! -e "$mysql_sock" ];then
		printf "Mysql is stopped...\n"
		exit 
	else
		printf "Stoping Mysql...\n"
		${cmd_path}/mysqladmin -u ${mysql_user} -p${mysql_pwd} -S ${mysql_sock} shutdown    # Stop the order 
	fi
}

#restart function
function_restart_mysql(){
    
	printf "Restart Mysql...\n"
	function_stop_mysql
	sleep 2
	function_start_mysql
}

case $1 in
start)
	function_start_mysql
	;;
stop)
	function_stop_mysql
	;;
restart)
	function_restart_mysql
	;;
*)
	printf "Usage:${cmd_path}/mysql.sh {start|stop|restart}\n"
esac

Script execution example :

#  start-up 3308 Port number mysql example 
sh /opt/modules/mysql/bin/mysql_instance.sh start 3308 root 123456

#  restart 
sh /opt/modules/mysql/bin/mysql_instance.sh restart 3308 root 123456
#