MySQL 5.7 Release Notes
MySQL Group Replication is provided as a plugin for the MySQL server; each server in a group requires configuration and installation of the plugin. This section provides a detailed tutorial with the steps required to create a replication group with at least three members.
Tip
An alternative way to deploy multiple instances of MySQL is by using InnoDB Cluster, which uses Group Replication and wraps it in a programmatic environment that enables you to easily work with groups of MySQL server instances in the MySQL Shell 8.0. In addition, InnoDB Cluster interfaces seamlessly with MySQL Router and simplifies deploying MySQL with high availability. See MySQL AdminAPI.