Linux 安装 MySQL

Linux 安装 MySQL

下载

在官网下载 mysql 包
这里以 mysql-5.7.35-linux-glibc2.12-x86_64.tar.gz 为例

解压

tar -zxvf mysql-5.7.35-linux-glibc2.12-x86_64.tar.gz

重命名

mv mysql-5.7.35-linux-glibc2.12-x86_64 mysql

移动

mv mysql /usr/local/

创建数据目录

mkdir /usr/local/mysql/data

创建用户组和用户（必须）

groupadd mysql
useradd -r -s /sbin/nologin -g mysql mysql -d /usr/local/mysql/

修改目录权限

chown -R mysql:mysql /usr/local/mysql/
chmod -R 755 /usr/local/mysql/

编辑配置文件

vim /etc/my.cnf

[mysqld]
bind-address=0.0.0.0
port=3306
user=mysql
max_allowed_packet=100M
max_connections=500
basedir=/usr/local/mysql
datadir=/usr/local/mysql/data
log-error=/usr/local/mysql/data/mysql.err
pid-file=/usr/local/mysql/data/mysql.pid
socket=/tmp/mysql.sock
character_set_server=utf8mb4
symbolic-links=0
explicit_defaults_for_timestamp=true
default-storage-engine=InnoDB

初始化（初始化完密码为空）

/usr/local/mysql/bin/mysqld --initialize-insecure

复制服务

cp /usr/local/mysql/support-files/mysql.server /etc/init.d/mysql

设置权限

chmod a+x /etc/init.d/mysql

设置开机自启

chkconfig --add /etc/init.d/mysql
chkconfig mysql on

服务启动

service mysql start

登录（初始密码为空直接回车即可）

/usr/local/mysql/bin/mysql -uroot -p

修改密码（123456改成自己想设置的密码）

alter user 'root'@'localhost' identified by '123456';

开启远程登录

update mysql.user set Host = '%' where User='root';

刷新

flush privileges;

退出

exit

其他

服务相关命令 启动 停止 重启

service mysql start
service mysql stop
service mysql restart

开机自启

chkconfig --add /etc/init.d/mysql
chkconfig mysql on

删除开机自启

chkconfig --del /etc/init.d/mysql

命令

查看连接数

# 查看当前连接总数
show status like 'Threads_connected%';

# 查看当前连接数，按用户分组
select USER , count(*) from information_schema.processlist group by USER;

# 查看当前连接数，按连接主机IP分组
select substring_index(host, ':',1) as host_name,state,count(*)
from information_schema.processlist group by state,host_name;

# 查看最大连接数
show variables like '%max_connections%';