MySQL多实例安装（相同版本）

时间：2022-04-18 00:21:27

本文以MySQL5.7为例，介绍在同一台机器下如何安装多个MySQL实例。
环境：RHEL 6.5 MySQL 5.7

1.单实例MySQL安装

先来看下MySQL5.7单实例的安装方法（这里引用官方文档的安装步骤）：

shell> groupadd mysql
shell> useradd -r -g mysql -s /bin/false mysql
shell> cd /usr/local
shell> tar zxvf /path/to/mysql-VERSION-OS.tar.gz
shell> ln -s full-path-to-mysql-VERSION-OS mysql
shell> cd mysql
shell> mkdir mysql-files
shell> chown mysql:mysql mysql-files
shell> chmod 750 mysql-files
shell> bin/mysqld --initialize --user=mysql 
shell> bin/mysql_ssl_rsa_setup              
shell> bin/mysqld_safe --user=mysql &
# Next command is optional
shell> cp support-files/mysql.server /etc/init.d/mysql.server

--修改/etc/profile 增加
export PATH=/usr/local/mysql/bin:$PATH

--需要修改密码才可以正常操作数据库：
mysql> show databases;
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql> alter user 'root'@'localhost' identified by '123';
Query OK, 0 rows affected (0.00 sec)

可以看到单实例MySQL的安装非常简单，只需创建了必要的用户组和用户，解压二进制软件包，初始化然后调整下权限基本就OK了。

2.多实例MySQL配置

下面来看下多实例MySQL配置，如果需要安装多实例在同一台机器上，主要4个地方的配置需要区分：端口（Port）、数据目录（datadir）、socket文件、server-id标识。（注：对其他配置可以根据实际需求去自定义各个实例的一些参数）
MySQL的配置文件my.cnf支持标签重定义，比如我这里安装4个实例，分别定义为[mysqld1]、[mysqld2]、[mysqld3]、[mysqld4]。

举例来说，我在原本的标准my.cnf配置文件中增加如下配置内容：

...这里省略原本的my.cnf配置内容...

[mysqld_multi]
mysqld=/usr/local/mysql/bin/mysqld_safe
mysqladmin=/usr/local/mysql/bin/mysqladmin
Log=/usr/local/mysql/multi.log

[mysqld1]
server-id=101
datadir=/data/mysqldata/3307
socket=/tmp/mysql.sock3307
port=3307

[mysqld2]
server-id=102
datadir=/data/mysqldata/3308
socket=/tmp/mysql.sock3308
port=3308

[mysqld3]
server-id=103
datadir=/data/mysqldata/3309
socket=/tmp/mysql.sock3309
port=3309

[mysqld4]
server-id=104
datadir=/data/mysqldata/3310
socket=/tmp/mysql.sock3310
port=3310

3.多实例MySQL初始化

多实例MySQL初始化：即分别初始化不同实例，也就是指定不同的datadir
bin/mysqld --initialize --user=mysql --datadir=/data/mysqldata/3307
bin/mysqld --initialize --user=mysql --datadir=/data/mysqldata/3308
bin/mysqld --initialize --user=mysql --datadir=/data/mysqldata/3309
bin/mysqld --initialize --user=mysql --datadir=/data/mysqldata/3310

--创建多实例各自的datadir
[[email protected] mysqldata]# pwd
/data/mysqldata
[[email protected] mysqldata]# mkdir 3307 3308 3309 3310

--具体参照安装单实例的步骤
[[email protected] local]# tar zxvf /public/ISO/mysql/mysql-5.7.28-linux-glibc2.12-x86_64.tar.gz 
[[email protected] local]# ln -s mysql-5.7.28-linux-glibc2.12-x86_64 mysql

--多实例MySQL初始化
[[email protected] mysql]# pwd
/usr/local/mysql
[[email protected] mysql]# bin/mysqld --initialize --user=mysql --datadir=/data/mysqldata/3307
[[email protected] mysql]# bin/mysqld --initialize --user=mysql --datadir=/data/mysqldata/3308
[[email protected] mysql]# bin/mysqld --initialize --user=mysql --datadir=/data/mysqldata/3309
[[email protected] mysql]# bin/mysqld --initialize --user=mysql --datadir=/data/mysqldata/3310

记录好每个MySQL实例默认生成的密码：

yD*jUO%pj4ta
aHiLky?Ge28k
psPWYuk/)8=j
<8Pk#rxteaqx

修改密码，我这里测试环境为了方便统一设置密码为123，如果是生产环境切记要设计符合客户要求的密码安全策略：

[[email protected] 3307]# mysql -uroot -S/tmp/mysql.sock3307 -p
yD*jUO%pj4ta
mysql> set password='123';

mysql -uroot -S/tmp/mysql.sock3308 -p
mysql -uroot -S/tmp/mysql.sock3309 -p
mysql -uroot -S/tmp/mysql.sock3310 -p

多实例MySQL开机启动项设置：

[[email protected] mysql]# chkconfig --list|grep mysql
[[email protected] mysql]# cp support-files/mysqld_multi.server /etc/init.d/mysqld_multi
[[email protected] mysql]# chkconfig --add mysqld_multi
[[email protected] mysql]# chkconfig --list|grep mysql
mysqld_multi    0:off   1:off   2:on    3:on    4:on    5:on    6:off

4.多实例MySQL常用管理命令

多实例MySQL常用管理命令：

--显示多实例mysqld的运行状态
mysqld_multi report

--启动[mysqld1]
mysqld_multi start 1

--启动[mysqld2]
mysqld_multi start 2

--启动所有多实例mysqld进程
mysqld_multi start

--通过socket连接到指定的MySQL实例
mysql -uroot -S/tmp/mysql.sock3307 -p
mysql -uroot -S/tmp/mysql.sock3308 -p
mysql -uroot -S/tmp/mysql.sock3309 -p
mysql -uroot -S/tmp/mysql.sock3310 -p

--确认连接实例的端口信息
show variables like '%port%';

最后确认下4个MySQL实例的启动、关闭均正常：

[[email protected] mysql]# mysqld_multi report
Reporting MySQL servers
MySQL server from group: mysqld1 is running
MySQL server from group: mysqld2 is running
MySQL server from group: mysqld3 is running
MySQL server from group: mysqld4 is running
[[email protected] mysql]# ps -ef|grep mysql
root     10923     1  0 23:48 pts/0    00:00:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --server-id=101 --datadir=/data/mysqldata/3307 --socket=/tmp/mysql.sock3307 --port=3307
root     10930     1  0 23:48 pts/0    00:00:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --server-id=102 --datadir=/data/mysqldata/3308 --socket=/tmp/mysql.sock3308 --port=3308
root     10947     1  0 23:48 pts/0    00:00:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --server-id=103 --datadir=/data/mysqldata/3309 --socket=/tmp/mysql.sock3309 --port=3309
root     10963     1  0 23:48 pts/0    00:00:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --server-id=104 --datadir=/data/mysqldata/3310 --socket=/tmp/mysql.sock3310 --port=3310
mysql    11438 10923  0 23:48 pts/0    00:00:00 /usr/local/mysql/bin/mysqld --basedir=/usr/local/mysql --datadir=/data/mysqldata/3307 --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --server-id=101 --log-error=jystdrac2.err --pid-file=jystdrac2.pid --socket=/tmp/mysql.sock3307 --port=3307
mysql    11461 10947  0 23:48 pts/0    00:00:00 /usr/local/mysql/bin/mysqld --basedir=/usr/local/mysql --datadir=/data/mysqldata/3309 --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --server-id=103 --log-error=jystdrac2.err --pid-file=jystdrac2.pid --socket=/tmp/mysql.sock3309 --port=3309
mysql    11463 10930  0 23:48 pts/0    00:00:00 /usr/local/mysql/bin/mysqld --basedir=/usr/local/mysql --datadir=/data/mysqldata/3308 --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --server-id=102 --log-error=jystdrac2.err --pid-file=jystdrac2.pid --socket=/tmp/mysql.sock3308 --port=3308
mysql    11472 10963  0 23:48 pts/0    00:00:00 /usr/local/mysql/bin/mysqld --basedir=/usr/local/mysql --datadir=/data/mysqldata/3310 --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --server-id=104 --log-error=jystdrac2.err --pid-file=jystdrac2.pid --socket=/tmp/mysql.sock3310 --port=3310
root     12228  7701  0 23:51 pts/0    00:00:00 grep mysql
[[email protected] mysql]# mysqld_multi stop
[[email protected] mysql]# mysqld_multi report
Reporting MySQL servers
MySQL server from group: mysqld1 is not running
MySQL server from group: mysqld2 is not running
MySQL server from group: mysqld3 is not running
MySQL server from group: mysqld4 is not running
[[email protected] mysql]# ps -ef|grep mysql
root     12400  7701  0 23:52 pts/0    00:00:00 grep mysql
[[email protected] mysql]# mysqld_multi start
[[email protected] mysql]# mysqld_multi report
Reporting MySQL servers
MySQL server from group: mysqld1 is running
MySQL server from group: mysqld2 is running
MySQL server from group: mysqld3 is running
MySQL server from group: mysqld4 is running
[[email protected] mysql]#

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