Remove mariaDB and install mysql 5.7 on Centos 7

Mysql 5.7 has JSON support but MariaDB currently does not. Your only option (for now) is to upgrade to 5.7:

Before you start download the correct repository from mysql. In this example we are using mysql57-community-release-el7-8.noarch.rpm

yum remove maria*


yum localinstall

yum install mysql

yum install mysql-server

yum install mysql-community-libs-compat

service mysqld start

If you get error Table 'performance_schema.session_variables' doesn't exist

mysql_upgrade -u root -p

Reinstall removed packages

yum install sphinx

yum install mytop

yum install postfix