Semantic peer-to-peer overlays for publish/subscribe 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. Most existing publish/subscribe systems suffer, however, from several drawbacks. They are usually based on a fixed infrastructure of reliable brokers, which cannot easily be modified or extended as the population of the producers and consumers evolves. Further, the challenging task of routing messages based on their content remains a complex and time-consuming operation, and often provides results that are just barely better than a simple broadcast. In this paper, we present a novel approach to publish/ subscribe that was designed to specifically address these issues. The producers and consumers are organized in a peer-to-peer network that self-adapts upon peer arrival, departure, or failure. Most importantly, our publish/subscribe system features an extremely simple and efficient routing process and excellent scalability to large consumer populations, both in terms of routing and peer management overhead.