In this recipe, you need a minimum of two Ceph clusters and a minimum of two object gateways (one for each Ceph cluster). This is a minimum requirement for RGW multi-site. 

This recipe assumes two Ceph object Gateway servers, named us-east-1 and us-west-1, with two respective Ceph clusters.

In a multi-site configuration, a master zone group and a master zone are required. Additionally, each zone group requires a master zone. Zone groups may have one or more secondary, or non-master, zones.

In this recipe, the us-east-1 host will serve as the master zone of the master zone group; the us-west-1 host will serve as the secondary zone of the master zone group.