MySQL 5.7--------多实例部署最佳实战

1. 背景

MySQL数据库的集中化运维，可以通过在一台服务器上，部署运行多个MySQL服务进程，通过不同的socket监听不同的服务端口来提供各自的服务。各个实例之间是相互独立的，每个实例的datadir, port, socket, pid都是不同的。

2. 多实例特点

* 有效利用服务器资源，当单个服务器资源有剩余时，可以充分利用剩余的资源提供更多的服务。

* 资源互相抢占问题，当某个服务实例服务并发很高时或者开启慢查询时，会消耗更多的内存、CPU、磁盘IO资源，导致服务器上的其他实例提供服务的质量下降。

3. 环境 [ 关闭SeLinux ]

[root@MySQL ~]# cat /etc/redhat-release CentOS release 6.9 (Final)[root@MySQL ~]# uname -r2.6.32-696.3.2.el6.x86_64[root@MySQL ~]# getenforce Disabled

4. 部署 [ 4个实例 ]

* 下载 MySQL 5.7 二制包 [ 推荐官方下载 ]　此下载版本大于5.7.5

[root@MySQL ~]# wget wget https://dev.mysql.com/get/Downloads/MySQL-5.7/mysql-5.7.18-linux-glibc2.5-x86_64.tar.gz

* 解压 MySQL 5.7 二进制包到指定目录

[root@MySQL ~]# tar zxvf mysql-5.7.18-linux-glibc2.5-x86_64.tar.gz -C /usr/local/

* 创建 MySQL 软链接

[root@MySQL ~]# ln -s /usr/local/mysql-5.7.18-linux-glibc2.5-x86_64 /usr/local/mysql

* 创建 MySQL 用户

[root@MySQL ~]# useradd -r -s /sbin/nologin mysql

* 在 MySQL 二进制包目录中创建 mysql-files 目录 [MySQL 数据导入/导出数据专放目录]

[root@MySQL ~]# mkdir -v /usr/local/mysql/mysql-filesmkdir: created directory `/usr/local/mysql/mysql-files'

* 创建多实例数据目录

[root@MySQL ~]# mkdir -vp /data/mysql_data{1..4}mkdir: created directory `/data'mkdir: created directory `/data/mysql_data1'mkdir: created directory `/data/mysql_data2'mkdir: created directory `/data/mysql_data3'mkdir: created directory `/data/mysql_data4'

* 修改 MySQL 二进制包目录的所属用户与所属组

[root@MySQL ~]# chown root.mysql -R /usr/local/mysql-5.7.18-linux-glibc2.5-x86_64

* 修改 MySQL 多实例数据目录与 数据导入/导出专放目录的所属用户与所属组

[root@MySQL ~]# chown mysql.mysql -R /usr/local/mysql/mysql-files /data/mysql_data{1..4}

* 配置 MySQL 配置文件 /etc/my.cnf

[mysqld_multi]mysqld     = /usr/local/mysql/bin/mysqld   mysqladmin = /usr/local/mysql/bin/mysqladminlog        = /tmp/mysql_multi.log[mysqld1]# 设置数据目录　[多实例中一定要不同]datadir = /data/mysql_data1# 设置sock存放文件名　[多实例中一定要不同]socket = /tmp/mysql.sock1# 设置监听开放端口　[多实例中一定要不同]port = 3306# 设置运行用户user = mysql# 关闭监控performance_schema = off# 设置innodb 缓存大小innodb_buffer_pool_size = 32M# 设置监听IP地址bind_address = 0.0.0.0# 关闭DNS 反向解析skip-name-resolve = 0[mysqld2]datadir = /data/mysql_data2socket = /tmp/mysql.sock2port = 3307user = mysqlperformance_schema = offinnodb_buffer_pool_size = 32Mbind_address = 0.0.0.0skip-name-resolve = 0[mysqld3]datadir = /data/mysql_data3socket = /tmp/mysql.sock3port = 3308user = mysqlperformance_schema = offinnodb_buffer_pool_size = 32Mbind_address = 0.0.0.0skip-name-resolve = 0[mysqld4]datadir = /data/mysql_data4socket = /tmp/mysql.sock4port = 3309user = mysqlperformance_schema = offinnodb_buffer_pool_size = 32Mbind_address = 0.0.0.0skip-name-resolve = 0

* 初始化各个实例 [ 初始化完成后会自带随机密码在输出日志中 ]

[root@MySQL ~]# /usr/local/mysql/bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/data/mysql_data1[root@MySQL ~]# /usr/local/mysql/bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/data/mysql_data2[root@MySQL ~]# /usr/local/mysql/bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/data/mysql_data3[root@MySQL ~]# /usr/local/mysql/bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/data/mysql_data4

* 各实例开启 SSL 连接

[root@MySQL ~]# /usr/local/mysql/bin/mysql_ssl_rsa_setup --user=mysql --basedir=/usr/local/mysql --datadir=/data/mysql_data1[root@MySQL ~]# /usr/local/mysql/bin/mysql_ssl_rsa_setup --user=mysql --basedir=/usr/local/mysql --datadir=/data/mysql_data2[root@MySQL ~]# /usr/local/mysql/bin/mysql_ssl_rsa_setup --user=mysql --basedir=/usr/local/mysql --datadir=/data/mysql_data3[root@MySQL ~]# /usr/local/mysql/bin/mysql_ssl_rsa_setup --user=mysql --basedir=/usr/local/mysql --datadir=/data/mysql_data4

* 复制多实例脚本到服务管理目录下 [ /etc/init.d/ ]

[root@MySQL ~]# cp /usr/local/mysql/support-files/mysqld_multi.server /etc/init.d/mysqld_multi

* 添加脚本执行权限

[root@MySQL ~]# chmod +x /etc/init.d/mysqld_multi

* 添加进service服务管理

[root@MySQL ~]# chkconfig --add mysqld_multi

5. 启动测试

* 查个多实例状态

[root@MySQL ~]# /etc/init.d/mysqld_multi reportReporting MySQL serversMySQL server from group: mysqld1 is not runningMySQL server from group: mysqld2 is not runningMySQL server from group: mysqld3 is not runningMySQL server from group: mysqld4 is not running

* 启动多实例

[root@MySQL ~]# /etc/init.d/mysqld_multi start

* 查看多实例状态

Reporting MySQL serversMySQL server from group: mysqld1 is runningMySQL server from group: mysqld2 is runningMySQL server from group: mysqld3 is runningMySQL server from group: mysqld4 is running

* 查看实例监听端口

[root@MySQL ~]# netstat -lntp | grep mysqldtcp        0      0 0.0.0.0:3306         0.0.0.0:*                LISTEN      2673/mysqld         tcp        0      0 0.0.0.0:3307         0.0.0.0:*                LISTEN      2676/mysqld         tcp        0      0 0.0.0.0:3308         0.0.0.0:*                LISTEN      2679/mysqld         tcp        0      0 0.0.0.0:3309         0.0.0.0:*                LISTEN      2682/mysqld

6. 连接测试

　 * 实例1

[root@MySQL ~]# /usr/local/mysql/bin/mysql -S /tmp/mysql.sock1  -p'z+Ilo*>s:3kw'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 6Server version: 5.7.18Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> set password = '123456';Query OK, 0 rows affected (0.00 sec)

　 * 实例2

[root@MySQL ~]# /usr/local/mysql/bin/mysql -S /tmp/mysql.sock2  -p'b*AHUrTgu1rl'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 7Server version: 5.7.18Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> set password = '123456';Query OK, 0 rows affected (0.00 sec)

7. 总结

以需求驱动技术，技术本身没有优略之分，只有业务之分。