Mediation. The messaging system acts as a mediator—as in the Mediator pattern [GoF]—between all of the programs that can send and receive messages. An application can use it as a directory of other applications or services available to integrate with. If an application becomes disconnected from the others, it need only reconnect to the messaging system, not to all of the other messaging applications. The messaging system can employ redundant resources to provide high availability, balance load, reroute around failed network connections, and tune performance and quality of service.
