实战-多实例安装MySQL8.0.20
目标：安装两个实例分别3306端口和3307端口，启动并登录成功。
1.下载安装包
cd /opt
wget https://dev.mysql.com/get/Downloads/MySQL-8.0/mysql-8.0.20-linux-glibc2.12-x86_64.tar.xz
2.解压文件
tar -xvf mysql-8.0.20-linux-glibc2.12-x86_64.tar.xz
3.移动解压后的数据文件（创建mysql8.0.20文件夹）
mv /opt/mysql-8.0.20-linux-glibc2.12-x86_64/* /usr/local/mysql8.0.20/
4.创建mysql组
groupadd mysql
5.创建mysql用户并添加到mysql组
useradd -g mysql mysql
6.创建3306端口和3307端口实例data/logs/tmp目录
mkdir -p /data/mysql8.0.20/mysql3306/{data,logs,tmp}
mkdir -p /data/mysql8.0.20/mysql3307/{data,logs,tmp}
7.修改目录权限
chown -R mysql:mysql /data/mysql8.0.20/mysql3306/{data,logs,tmp}
chown -R mysql:mysql /data/mysql8.0.20/mysql3307/{data,logs,tmp}
chown -R mysql:mysql /usr/local/mysql8.0.20
8.创建3306端口和3307端口实例*.cnf（参数配置）文件
3306端口实例配置文件mysql3306.cnf放到/data/mysql8.0.20/mysql3306/tmp下，以下为基础参数
[mysqld]
port=3306
socket=/tmp/mysql3306.sock
basedir=/usr/local/mysql8.0.20
datadir=/data/mysql8.0.20/mysql3306/data
tmpdir=/data/mysql8.0.20/mysql3306/tmp
#error log
log-error=/data/mysql8.0.20/mysql3306/logs/mysql_error.log
log_error_verbosity=3
3307端口实例配置文件mysql3307.cnf放到/data/mysql8.0.20/mysql3307/tmp下，以下为基础参数
[mysqld]
port=3307
socket=/data/mysql8.0.20/mysql3307/tmp/mysql3307.sock
basedir=/usr/local/mysql8.0.20
datadir=/data/mysql8.0.20/mysql3307/data
tmpdir=/data/mysql8.0.20/mysql3307/tmp
#error log
log-error=/data/mysql8.0.20/mysql3307/logs/mysql_error.log
log_error_verbosity=3
3307端口实例配置文件
9.初始化数据库
9.1#有密码初始化
9.1.1初始化3306端口实例
/usr/local/mysql8.0.20/bin/mysqld --defaults-file=/data/mysql8.0.20/mysql3306/tmp/mysql3306.cnf --user=mysql --initialize
9.1.2初始化3307端口实例
/usr/local/mysql8.0.20/bin/mysqld --defaults-file=/data/mysql8.0.20/mysql3307/tmp/mysql3307.cnf --user=mysql --initialize
9.2#无密码初始化
9.2.1初始化3306端口实例
/usr/local/mysql8.0.20/bin/mysqld --defaults-file=/data/mysql8.0.20/mysql3306/tmp/mysql3306.cnf --user=mysql --initialize-insecure
9.2.2初始化3307端口实例
/usr/local/mysql8.0.20/bin/mysqld --defaults-file=/data/mysql8.0.20/mysql3307/tmp/mysql3307.cnf --user=mysql --initialize-insecure
10.查看密码（如果选择无密码初始化，可跳过此步）
10.1查看3306端口实例登录密码
cat /data/mysql8.0.20/mysql3306/logs/mysql_error.log
10.2查看3307端口实例登录密码
cat /data/mysql8.0.20/mysql3307/logs/mysql_error.log
11.启动数据库
11.1启动3306端口实例
[root@centos-7 ~]# /usr/local/mysql8.0.20/bin/mysqld_safe --defaults-file=/data/mysql8.0.20/mysql3306/tmp/mysql3306.cnf --user=mysql &
[1] 6649
[root@centos-7 ~]# 2020-07-13T06:27:00.146171Z mysqld_safe Logging to '/data/mysql8.0.20/mysql3306/logs/mysql_error.log'.
2020-07-13T06:27:00.209045Z mysqld_safe Starting mysqld daemon with databases from /data/mysql8.0.20/mysql3306/data
我们看下后台是否有这个进程
[root@centos-7 ~]# ps aux | grep mysql
root 6649 0.2 0.0 113620 1720 pts/0 S 14:26 0:00 /bin/sh /usr/local/mysql8.0.20/bin/mysqld_safe --defaults-file=/data/mysql8.0.20/mysql3306/tmp/mysql3306.cnf --user=mysql
mysql 7024 9.1 11.4 3027340 443460 pts/0 Sl 14:26 0:01 /usr/local/mysql8.0.20/bin/mysqld --defaults-file=/data/mysql8.0.20/mysql3306/tmp/mysql3306.cnf --basedir=/usr/local/mysql8.0.20 --datadir=/data/mysql8.0.20/mysql3306/data --plugin-dir=/usr/local/mysql8.0.20/lib/plugin --user=mysql --log-error=/data/mysql8.0.20/mysql3306/logs/mysql_error.log --pid-file=centos-7.shared.pid --socket=/tmp/mysql3306.sock --port=3306
root 7141 0.0 0.0 112824 980 pts/0 S+ 14:27 0:00 grep --color=auto mysql
发现3306端口进程存在，我们再看下错误日志，看有没有报错
[root@centos-7 ~]# cat /data/mysql8.0.20/mysql3306/logs/mysql_error.log
日志内容太多我就不粘贴了，我查看后发现未报错，从以上内容我们可以认为3306端口实例已经正常启动了。
11.2启动3307端口实例
[root@centos-7 ~]# /usr/local/mysql8.0.20/bin/mysqld_safe --defaults-file=/data/mysql8.0.20/mysql3307/tmp/mysql3307.cnf --user=mysql &
[2] 8458
[root@centos-7 ~]# 2020-07-13T06:33:52.877251Z mysqld_safe Logging to '/data/mysql8.0.20/mysql3307/logs/mysql_error.log'.
2020-07-13T06:33:52.937512Z mysqld_safe Starting mysqld daemon with databases from /data/mysql8.0.20/mysql3307/data
我们查看下后台进程是否有3307端口这个实例
[root@centos-7 ~]# ps aux | grep mysql
root 6649 0.0 0.0 113620 1720 pts/0 S 14:26 0:00 /bin/sh /usr/local/mysql8.0.20/bin/mysqld_safe --defaults-file=/data/mysql8.0.20/mysql3306/tmp/mysql3306.cnf --user=mysql
mysql 7024 1.3 11.4 3092876 443472 pts/0 Sl 14:26 0:09 /usr/local/mysql8.0.20/bin/mysqld --defaults-file=/data/mysql8.0.20/mysql3306/tmp/mysql3306.cnf --basedir=/usr/local/mysql8.0.20 --datadir=/data/mysql8.0.20/mysql3306/data --plugin-dir=/usr/local/mysql8.0.20/lib/plugin --user=mysql --log-error=/data/mysql8.0.20/mysql3306/logs/mysql_error.log --pid-file=centos-7.shared.pid --socket=/tmp/mysql3306.sock --port=3306
root 8458 0.0 0.0 113620 1720 pts/0 S 14:33 0:00 /bin/sh /usr/local/mysql8.0.20/bin/mysqld_safe --defaults-file=/data/mysql8.0.20/mysql3307/tmp/mysql3307.cnf --user=mysql
mysql 8830 1.5 11.2 2961232 435696 pts/0 Sl 14:33 0:04 /usr/local/mysql8.0.20/bin/mysqld --defaults-file=/data/mysql8.0.20/mysql3307/tmp/mysql3307.cnf --basedir=/usr/local/mysql8.0.20 --datadir=/data/mysql8.0.20/mysql3307/data --plugin-dir=/usr/local/mysql8.0.20/lib/plugin --user=mysql --log-error=/data/mysql8.0.20/mysql3307/logs/mysql_error.log --pid-file=centos-7.shared.pid --socket=/data/mysql8.0.20/mysql3307/tmp/mysql3307.sock --port=3307
root 9861 0.0 0.0 112824 980 pts/0 S+ 14:39 0:00 grep --color=auto mysql
我们看到后台进程有3307这个实例，同时也看到了3306端口实例。
我们再看下3307端口实例启动过程中是否有报错
[root@centos-7 ~]# cat /data/mysql8.0.20/mysql3307/logs/mysql_error.log
日志太多不粘贴了，我查看后发现未报错，从以上内容我们可以认为3307端口实例也已经正常启动了。
12.登录数据库
12.1登录3306端口实例
[root@centos-7 ~]# /usr/local/mysql8.0.20/bin/mysql -uroot -p -S /tmp/mysql3306.sock
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.20 MySQL Community Server - GPL
Copyright (c) 2000, 2020, 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 variables like 'port';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| port | 3306 |
+---------------+-------+
1 row in set (0.00 sec)
3306端口实例登录成功
12.2登录3307端口实例
/usr/local/mysql8.0.20/bin/mysql -uroot -p -S /data/mysql8.0.20/mysql3307/tmp/mysql3307.sock
[root@centos-7 ~]# /usr/local/mysql8.0.20/bin/mysql -uroot -p -S /data/mysql8.0.20/mysql3307/tmp/mysql3307.sock
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.20 MySQL Community Server - GPL
Copyright (c) 2000, 2020, 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 variables like 'port';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| port | 3307 |
+---------------+-------+
1 row in set (0.01 sec)
3307端口实例也登录成功了
13.修改密码
13.1修改3306端口实例密码
mysql>alter user root@localhost identified by 'Root!3306'
13.1修改3307端口实例密码
mysql>alter user root@localhost identified by 'Root!3307'
实战成功完成。