错误提示：Job for mysql.service failed because the control process exited with error code.

通过openstack源码部署过程中遇到以下错误提示：

问题：

Job for mysql.service failed because the control process exited with error code. See "systemctl status mysql.service" and "journalctl -xe" for details.

解决方案：原因是由于版本问题，导致安装的插件文件名称不一致，所以不能正常安装：

    将以下运行命令：

        vim /etc/mysql/mariadb.conf.d/ 99 -openstack.cnf

    修改为运行：

        vim /etc/mysql/mariadb.conf.d/ 50 -openstack.cnf

注：红色字体的具体数字根据 /etc/mysql/mariadb.conf.d/ 目录下的文件改动