A Scalable P2P Architecture for Topic-Based Event Dissemination

The completely decoupled interaction model offered by the publish/subscribe communication paradigm perfectly suits the interoperability needs of todays large-scale, dynamic, peer-to-peer applications. Unmanaged inter-administrative environments, where these applications are ex-pected to work, pose a series of problems (potentially wide number of partipants, low-reliability of nodes, absence of a centralized authority, etc.) that severely limit the scalability of existing approaches which were originally thought for supporting distributed applications built on the top of static and managed environments. In this paper we propose a novel architecture for implementing the topic-based publish/subscribe paradigm in large scale peer-to-peer systems. The proposed architecture is based on probabilistic mechanisms and peer-to-peer overlay man-agement protocols. It achieves event diffusion by implementing traffic confinement (published events have a high probability to reach only interested subscribers), high scalability (with respect to several fundamental parameters like number of participants, subscriptions, topics and event publication rate) and fair load distribution (load distribution closely follows the distribution of subscription on nodes).