Chapter 21 InnoDB Cluster Important 3915 This chapter introduces MySQL InnoDB Cluster, which combines MySQL technologies to enable you to deploy and administer a complete integrated high availability solution for MySQL. This content is a high- level overview of InnoDB Cluster, for full documentation, see MySQL InnoDB Cluster. InnoDB Cluster does not provide support for MySQL NDB Cluster. For more information about MySQL NDB Cluster, see Chapter 23,  MySQL NDB Cluster 8.0 and Section 23.1.6, “MySQL Server Using InnoDB Compared with NDB Cluster” . An InnoDB Cluster consists of at least three MySQL Server instances, and it provides high-availability and scaling features. InnoDB Cluster uses the following MySQL technologies: The following diagram shows an overview of how these technologies work together: •MySQL Shell, which is an advanced client and code editor for MySQL. •MySQL Server, and Group Replication, which enables a set of MySQL instances to provide high- availability. InnoDB Cluster provides an alternative, easy to use programmatic way to work with Group Replication. •MySQL Router, a lightweight middleware that provides transparent routing between your application and InnoDB Cluster.