MySQL Shell Read Replicas are read-only copies of a Cluster member. Asynchronous replication keeps the replica up to date, enabling you to scale out your workload, offload read requests from your Cluster to one, or more, dedicated read-only instances, and provide additional redundancy to your dataset. In the event of a failure of the source, the Read Replica automatically connects to another Cluster member and resumes replication.
Read Replicas can be configured to replicate from any member of the Cluster. By default, they replicate from the primary. You can also promote Read Replicas to secondary Cluster members and demote secondary Cluster members to Read Replicas.