MariaDB 是 MySQL 的一个分支，采用 GPL 授权许可证，目前主要由开源社区在维护。MariaDB的目的是完全兼容MySQL，包括 API 和命令行，是之能轻松成为 MySQL 的替代品。
通过 yum 方式安装 MariaDB 非常简单，执行如下命令即可。
# yum install mariadb-server mariadb
# rpm -q mariadb mariadb-server
mariadb-5.5.56-2.el7.x86_64
mariadb-server-5.5.56-2.el7.x86_64
安装完成后，将 MariaDB 设置为开机启动，操作如下：
# systemctl enable mariadb
输出类似如下：
Created symlink from /etc/systemd/system/multi-user.target.wants/mariadb.service to /usr/lib/systemd/system/mariadb.service.
接着，启动 MariaDB，执行如下命令：
# systemctl start mariadb
最后，登录 MariaDB，执行如下命令：
# mysql -uroot -p
Enter password:
Welcome to the MariaDB monitor. Commands end with ; or g.
Your MariaDB connection id is 2
Server version: 5.5.56-MariaDB MariaDB Server
Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.
MariaDB [(none)]>
从这里可以看到，在 MariaDB 中，默认的登录方式跟 MySQL 数据库一样，root 密码默认为空。
对 MariaDB 服务进行管理，可以通过 systemctl 命令实现。例如：
关闭 MariaDB
# systemctl stop mariadb
重启 MariaDB
# systemctl restart mariadb
检查 MariaDB 服务运行状态
# systemctl status mariadb
MariaDB 通过内置的安全脚本可实现对数据库的安全保护，执行“/usr/bin/mysql_secure_installation”命令，加固 MariaDB 数据库，操作过程如下：
# mysql_secure_installation
NOTE: RUNNING ALL PARTS OF THIS SCRIPT IS RECOMMENDED FOR ALL MariaDB
SERVERS IN PRODUCTION USE! PLEASE READ EACH STEP CAREFULLY!
In order to log into MariaDB to secure it, we'll need the current
password for the root user. If you've just installed MariaDB, and
you haven't set the root password yet, the password will be blank,
so you should just press enter here.
Enter current password for root (enter for none): // 这里输入目前 MariaDB 数据库的 root 密码，默认为空
OK, successfully used password, moving on...
Setting the root password ensures that nobody can log into the MariaDB
root user without the proper authorisation.
Set root password? [Y/n] y // 这里询问是否是之 root 密码，输入 y 给 root 用户设置一个新密码
New password:
Re-enter new password:
Password updated successfully!
Reloading privilege tables..
... Success!
By default, a MariaDB installation has an anonymous user, allowing anyone
to log into MariaDB without having to have a user account created for
them. This is intended only for testing, and to make the installation
go a bit smoother. You should remove them before moving into a
production environment.
Remove anonymous users? [Y/n] y //这里询问是否删除 anonymous 用户，输入 "Y"
... Success!
Normally, root should only be allowed to connect from 'localhost'. This
ensures that someone cannot guess at the root password from the network.
Disallow root login remotely? [Y/n] y // 这里询问是否关闭 root 用户远程登录权限 输入 "Y"
... Success!
By default, MariaDB comes with a database named 'test' that anyone can
access. This is also intended only for testing, and should be removed
before moving into a production environment.
Remove test database and access to it? [Y/n] y // 这里询问是否删除测试数据库及其权限 输入 "Y"
- Dropping test database...
... Success!
- Removing privileges on test database...
... Success!
Reloading the privilege tables will ensure that all changes made so far
will take effect immediately.
Reload privilege tables now? [Y/n] y // 这里询问是否重新载入授权表 输入 "Y"
... Success!
Cleaning up...
All done! If you've completed all of the above steps, your MariaDB
installation should now be secure.
Thanks for using MariaDB!
至此，MariaDB 数据库安转完成了。
