Enabling content-based publish/subscribe services in cooperative P2P networks

P2P is a popular networking paradigm in today’s internet. As such, many research and development efforts are geared toward services that can be useful to the users of P2P networks. This paper is focused on the content-based publish/subscribe service and our problem is to devise an efficient mechanism that enables this service in any given P2P network of cooperative nodes. Most techniques require some overlay structure added on top of the network. We propose an efficient solution called PUB-2-SUB which works with any unstructured network topology. In addition, multiple independent publish/subscribe applications can run simultaneously on a single instance of PUB-2-SUB. The proposed technique is based on two key components: the virtualization component and the indexing component. The virtualization component assigns to each node a unique binary string virtual address and, accordingly, a unique zone partitioned from the universe of binary strings. The indexing component hashes queries and publications to binary strings and, based on their overlapping with the node zones, chooses subscription and notification paths appropriately and deterministically. PUB-2-SUB works best for P2P-based cooperative networks such as data grid networks and institutional collaborative networks. Our theoretical findings are complemented by a simulation-based evaluation. 2010 Elsevier B.V. All rights reserved.