Message Broker Pattern
You can use the FTL server to implement a message broker, an intermediate store-and-forward service between publishers and subscribers.
The default configuration of an FTL server implements a message broker. That is, when you run one FTL server without supplying any configuration file, it automatically operates as a message broker. Moreover, when you run three FTL servers without supplying any configuration file, they automatically join together to operate as a message broker.
When application programs interact with the message broker, its default behavior uses a non-persistent store and standard durables. This behavior is equivalent, in EMS terminology, to non-persistent messaging through topics. (You can explicitly configure persistent messaging behavior and queue behavior.)