10.3. Broker Federation Overview
10.3.1. Message Routes
Broker Federation is done by creating message routes. The destination for a route is always an exchange on the destination broker.
By default, a message route is created by configuring the destination broker, which then contacts the source broker to subscribe to the source queue. This is called a pull route.
It is also possible to create a route by configuring the source broker, which then contacts the destination broker to send messages. This is called a push route, and is particularly useful when the destination broker may not be available at the time the messaging route is configured, or when a large number of routes are created with the same destination exchange.
The source for a route can be either an exchange or a queue on the source broker. If a route is between two exchanges, the routing criteria can be given explicitly, or the bindings of the destination exchange can be used to determine the routing criteria. To support this functionality, there are three kinds of message routes:
- Queue routes
- Exchange routes
- Dynamic exchange routes
