Extend Kea HA to permit a single backup server for multiple primary/active servers

As an administrator with many offices, each with a local Kea server, I would prefer to have a single backup server, centrally located, that can serve as backup for many remote Kea servers.

I realize that one option is to run multiple Kea servers on the single machine at HQ, but monitoring and managing that single Kea server would also present scaling issues. This request is to be able to have a single Kea server that has multiple failover relationships.

• The scale would be dozens of remote active nodes to a single passive node.
• In this scenario, the active Kea servers are not likely to be heavily loaded or extremely active.
• It is ok if the central server is limited in the number of relationships in which it can become the primary simultaneously.