Efficient subscription management in content based networks

Content-based publish/subscribe systems offer a convenient abstraction for data producer and consumers, as most of the complexity related to addressing and routing is encapsulated within the network infrastructure. A major challenge of content-based networks is their ability to efficiently cope with changes in consumer membership. In our XNET XML content network, we have addressed this issue by designing novel algorithms to speed up subscription management at the routers, while guaranteeing perfect routing at all times and maintaining compact routing tables thanks to extensive usage of ?aggregation.? In this paper, we discuss the issue of subscription management in content-based networks, and we specifically describe and evaluate the algorithms that we have developed for XNET.