https://www.cnblogs.com/longren/p/11168317.html
step1:卸载所有与mysql,mariadb相关的东西
卸载mysql
# rpm -qa | grep mysql
yum -y remove mysql-community-common-5.7.29-1.el7.x86_64
yum -y remove mysql-community-client-5.7.29-1.el7.x86_64
yum -y remove mysql-community-libs-5.7.29-1.el7.x86_64
yum -y remove mysql-community-server-5.7.29-1.el7.x86_64
卸载MariaDB
# rpm -qa | grep mariadb
将它们统统强制性卸载掉：
# rpm -e --nodeps mariadb-libs-5.5.35-3.el7.x86_64
# rpm -e --nodeps mariadb-5.5.35-3.el7.x86_64
# rpm -e --nodeps mariadb-server-5.5.35-3.el7.x86_64
#yum -y remove mariadb*
step2：安装依赖包
#yum -y install make gcc-c++ gcc cmake bison-devel ncurses-devel libaio libaio-devel
step3:创建mysql用户
tar -xvf mysql-5.6.32-linux-glibc2.5-x86_64.tar.gz -C /usr/local/mysql
port分开：默认3306
socket分开：默认（/var/lib/mysql/mysql.sock）
mysqld服务运行时，产生socket文件，客户端访问数据库时，与socket文件建立连接
日志分开：默认(/var/log/mysqld.log)
数据目录分开：默认(/var/lib/mysql)
pid文件分开：默认(/var/run/mysqld/mysqld.pid)