Cascading replication is a topology that has multiple tiers
of servers. You can use the information and example provided here
to know more about it.
A master server replicates to a set of read-only (forwarding) servers
that in turn replicate to other servers.Such a topology off-loads
replication work from the master server. In the example of this type
of topology, the master server is a supplier to the two forwarding
servers. The forwarding servers serve two roles. They are consumers
of the master server and suppliers to the replica servers associated
with them. The replica servers are consumers of their respective forwarding
servers. For example: Figure 1. Cascading replication
