Basic Operation

A zone is a named set of routes. Every route belongs to a zone.

A zone affects the forwarding behavior of its routes:

  • In a multi-hop (mhop) zone, topic messages travel along all applicable routes to all servers connected by routes within the zone.
  • In a one-hop (1hop) zone, topic messages travel only one hop (from the first server).
  • Queue messages travel only one hop, even within multi-hop zones.

For example, the following figure depicts a set of servers connected by routes within a multi-hop zone, Z1. If a client sends a message to a global topic on server B, the servers forward the message to A, C, D and E (assuming there are subscribers at each of those servers). In contrast, if Z1 were a one-hop zone, B would forward the message to A, C and D—but D would not forward it E.