Active/passive chained replication topology details
What this looks like
The following figure shows an active/passive chained replication topology in which system A is replicating to system B and system B is replicating to system C.

In this figure:
- From system A, two HCP tenants are being replicated to system B. In the first tenant, two of three namespaces are selected for replication. In the second tenant, one of two namespaces is selected for replication.
- From system B, the tenants and namespaces created by replication from system A are being replicated to system C because the link from A to B is included in the link from B to C.
- One tenant that was originally created on system B is also being replicated to system C. Both the namespaces in that tenant are selected for replication.
Uses
In an active/passive chained replication topology, all three HCP systems typically are located at full-scale data centers. For example, suppose a corporation has three major locations: New York, Los Angeles, and Tokyo. Each of these locations runs an application that is vital to the corporation, but only New York generates the data for these applications. Replicating the data from New York to Los Angeles and from Los Angeles to Tokyo enables applications at each location to access the data through a local area network. Because those applications are not accessing the data on the HCP system in New York, this topology also reduces the load on that system.
Active/passive chained replication helps ensure continuous data availability. If any one or even two of the HCP systems in the chain become unavailable, applications still have access to the stored data.
In an active/passive replication chain, the third HCP system provides disaster recovery functionality for the second system, and the second system provides disaster recovery functionality for the first system.
With an active/passive chained replication topology, you can create and manage both replication links from the HCP system in the middle of the chain. To this system, the link from the first system is an inbound link, and the link to the third system is an outbound link.