PUBLISH/SUBSCRIBE MESSAGE ROUTING

Message routing in a publish/subscribe system where messages are routed from one or more publishers to one or more subscribers according to respective defined paths through a topic tree. A pseudo-topic tree path comprised of a partial path definition and a selection function is specified by a subscriber or publisher. When executed, the selection function searches the topic tree to identify one or more path definition segments, which segments replace the selection function in the pseudo-topic tree path to generate one or more complete path definitions that are then usable for routing messages.