QTor: A flexible publish/subscribe peer-to-peer organization based on query rewriting

Abstract

Peer-to-peer publish/subscribe architectures are an interesting support for scalable distributed data stream applications. Most approaches, often based on brokers, have a static organization which is not much adaptive to different configurations of the participants’ capacities. We present QTor (Query Torrent) a generic organization that enables dynamic adaptation providing a continuum from centralized to fully decentralized solutions. Based on query rewriting and equivalence, QTor proposes a definition of communities and their relations that decouples the logical and physical aspects of the problem, while efficiently reducing organizational and functional costs.