yum or rpm？
yum安装方式很方便，但是下载mysql的时候从官网下载，速度较慢。
rpm安装方式可以从国内镜像下载mysql的rpm包，比较快。rpm也适合离线安装。
环境说明
操作系统：Centos7.4 (CentOS-7-x86_64-Minimal-1804.iso)
mysql：mysql8.0.13
卸载系统自带的mariadb-lib
查看mariadb版本
rpm -qa|grep mariadb
mariadb-libs-5.5.56-2.el7.x86_64
卸载mariadb
rpm -e mariadb-libs-5.5.56-2.el7.x86_64 --nodeps
安装依赖环境
yum install -y openssl-devel.x86_64 openssl.x86_64
yum install -y libaio.x86_64 libaio-devel.x86_64
yum install -y perl.x86_64 perl-devel.x86_64
yum install -y perl-JSON.noarch
yum install -y autoconf
yum install -y wget
yum install -y net-tools
关闭防火墙
systemctl stop firewalld.service
systemctl disable firewalld.service
禁用selinux
vi /etc/selinux/config
将SELINUX=enforcing改为SELINUX=disabled
reboot 重启机器
从网易镜像下载mysql安装包集合
下载完整安装包并解压
wget https://mirrors.163.com/mysql/Downloads/MySQL-8.0/mysql-8.0.13-1.el7.x86_64.rpm-bundle.tar
tar -xvf mysql-8.0.13-1.el7.x86_64.rpm-bundle.tar
下载必要安装包（二选一）
wget https://mirrors.163.com/mysql/Downloads/MySQL-8.0/mysql-community-common-8.0.13-1.el7.x86_64.rpm
wget https://mirrors.163.com/mysql/Downloads/MySQL-8.0/mysql-community-libs-8.0.13-1.el7.x86_64.rpm
wget https://mirrors.163.com/mysql/Downloads/MySQL-8.0/mysql-community-client-8.0.13-1.el7.x86_64.rpm
wget https://mirrors.163.com/mysql/Downloads/MySQL-8.0/mysql-community-server-8.0.13-1.el7.x86_64.rpm
按顺序安装
必要安装（注意顺序）
安装common
安装lib 依赖于common，确保已经卸载mariadb
依赖于libs
依赖于client、common
rpm -ivh mysql-community-common-8.0.13-1.el7.x86_64.rpm
rpm -ivh mysql-community-libs-8.0.13-1.el7.x86_64.rpm
rpm -ivh mysql-community-client-8.0.13-1.el7.x86_64.rpm
rpm -ivh mysql-community-server-8.0.13-1.el7.x86_64.rpm
非必要安装（注意顺序）
rpm -ivh mysql-community-libs-compat-8.0.13-1.el7.x86_64.rpm
rpm -ivh mysql-community-embedded-compat-8.0.13-1.el7.x86_64.rpm
rpm -ivh mysql-community-devel-8.0.13-1.el7.x86_64.rpm
rpm -ivh mysql-community-test-8.0.13-1.el7.x86_64.rpm
初始化数据库
mysqld --initialize --console
目录授权，否则启动失败
chown -R mysql:mysql /var/lib/mysql/
启动服务
systemctl start mysqld
加密
mysql_secure_installation
其他
其他操作和yum安装方式一样，不再重复。
安装perl所有模块
yum install -y perl-Module-Install.noarch
