2.1 问题
在主机192.168.4.57上：
配置第1个MySQL实例
实例名称mysqld1、端口3307
数据库目录/dir2、pid文件mysqld1.pid
错误日志mysqld1.err、socket文件mysqld1.socket
配置第2个MySQL实例
实例名称mysqld2、端口3308
数据库目录/dir1、pid文件mysqld2.pid
错误日志mysqld2.err、socket文件mysqld2.socket
步骤一：配置多实例（192.168.4.57上操作）
什么是多实例：
在一台物理主机上运行多个数据库服务，可以节约运维成本，提高硬件利用率
1）解压软件、修改目录名、设置PATH路径
]# yum –y install libaio
]# useradd mysql
]# tar -zxvf mysql-5.7.20-linux-glibc2.12-x86_64.tar.gz
]# mv mysql-5.7.20-linux-glibc2.12-x86_64 /usr/local/mysql
]# PATH=/usr/local/mysql/bin:$PATH
]# vim /etc/bashrc
export PATH=/usr/local/mysql/bin:$PATH
:wq
2）编辑主配置文件/etc/my.cnf
每个实例要有独立的数据库目录、监听端口号、实例名称和独立的sock文件
]# vim /etc/my.cnf
[mysqld_multi] //启用多实例
mysqld = /usr/local/mysql/bin/mysqld_safe //指定进程文件路径
mysqladmin = /usr/local/mysql/bin/mysqladmin //指定管理命令路径
user = root //指定进程用户
[mysqld1] //实例进程名称
port=3307 //端口号
datadir=/dir1 //数据库目录 ，要手动创建
socket=/dir1/mysqld1.sock //指定sock文件的路径和名称
pid-file=/dir1/mysqld1.pid //进程pid号文件位置
log-error=/dir1/mysqld1.err //错误日志位置
[mysqld2]
port=3308
datadir=/dir2
socket=/dir2/mysqld2.sock
pid-file=/dir2/mysqld2.pid
log-error=/dir2/mysqld2.err
:wq
3）创建数据库目录
]# mkdir /dir2
]# mkdir /dir1
4）启动多实例
首次启动服务会做数据初始化 并初始和提示数据库管理员本机登录密码
[root@host57 ~]# mysqld_multi start 1 //启动实例1
Installing new database in /dir1
2019-06-13T10:46:29.307866Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2019-06-13T10:46:30.997233Z 0 [Warning] InnoDB: New log files created, LSN=45790
2019-06-13T10:46:31.436904Z 0 [Warning] InnoDB: Creating foreign key constraint system tables.
2019-06-13T10:46:31.582129Z 0 [Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: 816bf015-8dc8-11e9-b492-525400cffedc.
2019-06-13T10:46:31.605276Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened.
2019-06-13T10:46:31.606321Z 1 [Note] A temporary password is generated for root@localhost: ly#LryiFE5fT 管理员本机登录密码
]# ls /dir1 //查看数据库目录文件列表
auto.cnf ib_buffer_pool ibdata1 ib_logfile0 ib_logfile1 ibtmp1 mysql mysql3307.log mysql3307.pid mysql3307.sock mysql3307.sock.lock performance_schema sys
]# mysqld_multi start 2 //启动实例2
Installing new database in /dir1
2019-06-13T10:56:55.580796Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2019-06-13T10:56:57.199217Z 0 [Warning] InnoDB: New log files created, LSN=45790
2019-06-13T10:56:57.571839Z 0 [Warning] InnoDB: Creating foreign key constraint system tables.
2019-06-13T10:56:57.708168Z 0 [Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: f69f30fa-8dc9-11e9-8a17-525400cffedc.
2019-06-13T10:56:57.724096Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened.
2019-06-13T10:56:57.724677Z 1 [Note] A temporary password is generated for root@localhost: qedTjrZs*8ma 管理员本机登录密码
]# ls /dir1 //查看数据库目录文件列表
auto.cnf ib_buffer_pool ibdata1 ib_logfile0 ib_logfile1 ibtmp1 mysql mysql3308.log mysql3308.pid mysql3308.sock mysql3308.sock.lock performance_schema sys
5）查看端口
]# netstat -utnlp | grep :3307
tcp6 0 0 :::3307 :::* LISTEN 1151/mysqld
]# netstat -utnlp | grep :3308
tcp6 0 0 :::3308 :::* LISTEN 1339/mysqld
]# netstat -utnlp | grep mysqld
tcp6 0 0 :::3307 :::* LISTEN 1151/mysqld
tcp6 0 0 :::3308 :::* LISTEN 1339/mysqld
# ps -C mysqld
PID TTY TIME CMD
1151 pts/1 00:00:00 mysqld
1339 pts/1 00:00:00 mysqld
[root@host57 ~]#
6）访问多实例
使用初始化密码登录实例1
[root@host57 ~]# mysql -uroot -p'ly#LryiFE5fT' -S /dir1/mysqld1.sock
mysql> alter user root@"localhost" identified by "123456"; //修改密码
mysql> exit
Bye
[root@host57 ~]# mysql -uroot -p123456 -S /dir1/mysqld1.sock //新密码登录
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.20 MySQL Community Server (GPL)
Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
+--------------------+
4 rows in set (0.00 sec)
mysql> create database db1; //创建新库db1
Query OK, 1 row affected (0.00 sec)
mysql> show databases; //查看已有的库
+--------------------+
| Database |
+--------------------+
| information_schema |
| db1 | //db1库
| mysql |
| performance_schema |
| sys |
+--------------------+
5 rows in set (0.00 sec)
mysql> exit //断开连接
Bye
[root@host56 ~]# ls /dir1 //查看数据库目录文件列表 有db1库的文件夹
auto.cnf ibdata1 ibtmp1 mysqld1.pid performance_schema
db1 ib_logfile0 mysql mysqld1.socket sys
ib_buffer_pool ib_logfile1 mysqld1.err mysqld1.socket.lock
[root@host56 ~]#
使用初始化密码登录实例2
[root@host57 ~]# mysql -uroot -p'qedTjrZs*8ma' -S /dir2/mysqld2.sock
mysql> alter user root@"localhost" identified by "654321"; //修改密码
mysql> exit
Bye
[root@host57 ~]# mysql -uroot –p654321 -S /dir2/mysqld2.sock //新密码登录
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.20 MySQL Community Server (GPL)
Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
+--------------------+
4 rows in set (0.00 sec)
mysql>
mysql> create database db2;
Query OK, 1 row affected (0.00 sec)
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| db2 |
| mysql |
| performance_schema |
| sys |
+--------------------+
5 rows in set (0.00 sec)
mysql> exit
Bye
[root@host56 ~]# ls /dir2
auto.cnf ib_logfile0 mysqld2.err performance_schema
db2 ib_logfile1 mysqld2.pid sys
ib_buffer_pool ibtmp1 mysqld2.socket
ibdata1 mysql mysqld2.socket.lock
[root@host56 ~]#
7）停止多实例服务
mysqld_multi --user=root --password=密码 stop 实例编号
]# netstat -utnlp | grep mysqld
tcp6 0 0 :::3307 :::* LISTEN 1250/mysql
tcp6 0 0 :::3308 :::* LISTEN 1451/mysql
]# mysqld_multi --user=root --password=123456 stop 2
[root@host56 ~]# netstat -utnlp | grep mysqld
tcp6 0 0 :::3307 :::* LISTEN 1250/mysql
]# mysql -uroot -p123456 -S /dir2/mysqld2.sock //拒绝连接
mysql: [Warning] Using a password on the command line interface can be insecure.
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/dir2/mysqld2.sock' (2)
