Setting Up a Readable Replica Database
A readable replica database is a secondary replica database that is typically used for reporting, backups or other non-production purpose. It is typically updated asynchronously and is maintained on a server that is independent from the primary and the secondary server that is designated as the failover partner.
There may be more than one readable replica database, but it must be a member of the same Windows Failover Cluster as the primary and secondary clusters.
The following sequence provides an example of adding a readable replica to an already existing AlwaysOn database cluster: