1.5. Asynchronous Communication

Red Hat JBoss Fuse supports two alternative mechanisms of asynchronous communication within the container: the JMS broker and the NMR bus.

You can optionally install a broker instance, typically Apache ActiveMQ, into the Red Hat JBoss Fuse container, to provide support for asynchronous communication between bundles in the container. Apache ActiveMQ is a sophisticated implementation of a JMS broker, which supports asynchronous communication using either queues or topics (publish-subscribe model). Some of the basic features of this JMS broker are as follows:

For details of how to set up a JMS broker in Red Hat JBoss Fuse, see Chapter 17, JMS Broker.

The Normalized Message Router (NMR) bus is an asynchronous messaging system that was originally developed in the context of the JBI standard. In the original specification of the NMR, the message was required to be in XML format and the destination addresses were required to conform to specific URI formats.

The NMR in Red Hat JBoss Fuse, however, has been modified from the original JBI specification. Although you can still use the NMR in the standard way in the context of the JBI container, there are some important differences when you use the NMR in the context of the OSGi container. In the context of OSGi, the NMR bus is much less restrictive, in particular: