CentOS7.3 部署两个实例 MySQL

描述

在同一台服务器中安装两个MySQL数据库。目的是为了配置主从分离，所以需要多安装一台用于从数据库。使用mysqld_multi启动多个实例。 mysql官网下载需要安装的版本。

下载与安装

在/usr/local/下创建mysqltemp（用于临时下载数据库安装包）。

[root@localhost local]# cd /usr/local
[root@localhost local]# mkdir mysqltemp
[root@localhost local]# cd mysqltemp
[root@localhost mysql3307]# wget https://cdn.mysql.com/archives/mysql-5.7/mysql-5.7.28-linux-glibc2.12-i686.tar.gz
[root@localhost mysql3307]# tar -xvf mysql-5.7.28-linux-glibc2.12-i686.tar.gz

//  重命名解压的文件为mysql，并移动mysql到/usr/local/mysql
[root@localhost mysql3307]# mv mysql-5.7.28-linux-glibc2.12-i686 /usr/local/mysql

下载、解压和重命名之后，完整路径是/usr/local/mysql。接下来进入mysql文件夹，创建data文件夹，并在data文件夹中创建3306、3307、log文件夹备用。在3306和3307文件夹中分别创建data、log、tmp文件夹备用。

[root@localhost mysql]# mkdir data
[root@localhost mysql]# cd data
[root@localhost data]# mkdir {3306,3307,log}
[root@localhost data]# cd 3306
[root@localhost 3306]# mkdir {data,log,tmp}
[root@localhost 3306]# cd ../3307
[root@localhost 3307]# mkdir {data,log,tmp}

配置

配置/etc/my.cnf文件

# vim /etc/my.cnf

使用以下配置

# 启动多个mysql实例
[client] 
default-character-set = utf8mb4

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

[mysqld3306] 
mysqld=mysqld
mysqladmin=mysqladmin
datadir=/usr/local/mysql/data/3306/data
port=3306
user=mysql
performance_schema = off
server_id=3306
socket=/tmp/mysql_3306.sock
MyISAM_buffer_pool_size = 32M         #设置MyISAM 缓存大小
bind_address = 0.0.0.0                  #设置监听IP地址
skip-name-resolve = 0                 #关闭DNS反向解析 
log-output=file
slow_query_log = 1
long_query_time = 1
slow_query_log_file = /usr/local/mysql/data/3306/log/slow.log
log-error = /usr/local/mysql/data/3306/log/error.log
binlog_format = mixed
log-bin = /usr/local/mysql/data/3306/log/mysql3306_bin
explicit_defaults_for_timestamp=true
lower_case_table_names = 1
  
[mysqld3307] 
mysqld=mysqld
mysqladmin=mysqladmin
datadir=/usr/local/mysql/data/3307/data
port=3307
user=mysql
server_id=3307
performance_schema = off
MyISAM_buffer_pool_size = 32M         #设置MyISAM 缓存大小
bind_address = 0.0.0.0                  #设置监听IP地址
skip-name-resolve = 0                 #关闭DNS反向解析 
socket=/tmp/mysql_3307.sock
log-output=file
slow_query_log = 1
long_query_time = 1
slow_query_log_file = /usr/local/mysql/data/3307/log/slow.log
log-error = /usr/local/mysql/data/3307/log/error.log
binlog_format = mixed
log-bin = /usr/local/mysql/data/3307/log/mysql3307_bin
explicit_defaults_for_timestamp=true
lower_case_table_names = 1

添加好配置文件之后，需要添加mysql用户（如果没有该用户的话）

# groupadd mysql
# useradd -g mysql mysql
# chown -R mysql:mysql /usr/local/mysql

初始化数据库

添加好配置之后，就可以初始化3306和3307的数据库了。执行命令之后，会出现临时密码，这个密码需要记住，用来首次登录mysql数据库。

# cd /usr/local/mysql

# ./bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql/ --datadir=/usr/local/mysql/data/3306/data

# ./bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql/ --datadir=/usr/local/mysql/data/3307/data

执行初始化命令，如果出现以下错误，则执行相应的安装命令即可。

./bin/mysqld: error while loading shared libraries: libaio.so.1: cannot open shared object file: No such file or directory

// 根据相应的提示，选择对应的安装命令
yum install -y libaio.so.1
yum install -y libnuma.so.1
yum install --setopt=protected_multilib=false libnuma.so.1

初始化数据库没有出现异常，最后会看到以下信息，说明初始化数据库成功，这也就是数据库的临时密码。

[Note] A temporary password is generated for root@localhost: 3/MasxQll5u

[Note] A temporary password is generated for root@localhost: 8tqGMruu8d?l

可以进入到data里面看看数据库有没有初始化成功。

# cd /usr/local/mysql/data/3306/data/
# cd /usr/local/mysql/data/3307/data/

启动

mysqld_multi多实例管理的基本命令

启动全部实例
# /usr/local/mysql/bin/mysqld_multi start

查看全部实例状态
# /usr/local/mysql/bin/mysqld_multi report

启动单个实例
# /usr/local/mysql/bin/mysqld_multi start 3306
# /usr/local/mysql/bin/mysqld_multi start 3307
停止单个实例
# /usr/local/mysql/bin/mysqld_multi stop 3306
# /usr/local/mysql/bin/mysqld_multi stop 3307
查看单个实例状态
# /usr/local/mysql/bin/mysqld_multi report 3306
# /usr/local/mysql/bin/mysqld_multi report 3307

使用命令，启动两个数据库实例

# /usr/local/mysql/bin/mysqld_multi start

执行命令没有报错，我们可以看一下日志有没有错误。

[root@localhost log]# cat /usr/local/mysql/data/log/mysqld_multi.log 
mysqld_multi log file version 2.16; run: 二 4月  7 13:04:42 2020

Starting MySQL servers

为了确保两个数据库实例已经启动，可以通过命令查看相应端口是否有进程。

# ps -ef | grep 3306
# ps -ef | grep 3307

或者查看相应的实例中的日志信息

# cat /usr/local/mysql/data/3307/log/error.log
# cat /usr/local/mysql/data/3307/log/error.log

mysql -S /tmp/mysql_3306.sock -p3/MasxQll5u

// 设置密码
mysql> set password=password('Root@123');
// 设置允许远程登录
mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'Root@123' WITH GRANT OPTION;
mysql> flush privileges;

mysql> show variables like '%character%';
mysql> show variables like "%case%";

3307数据库同样跟3306操作一样。

mysql -S /tmp/mysql_3307.sock -p8tqGMruu8d?l

// 设置密码
mysql> set password=password('Root@123');
// 设置允许远程登录
mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'Root@123' WITH GRANT OPTION;
mysql> flush privileges;

mysql> show variables like '%character%';
mysql> show variables like "%case%";

关闭数据库，发现使用/usr/local/mysql/bin/mysqld_multi stop不能关闭。可以先查询端口进程，然后用kill命令关闭。