DiffLookup: Differentiated Lookup Services Provision in P2P Networks

Data heterogeneity has been widely observed in P2P content distribution systems. However, most current content location algorithms treat different data objects equally and use the same search scheme for them. We propose a Data-oriented Differentiated Lookup mechanism (DiffLookup), aiming to provide differentiated lookup services with simple and flexible design. DiffLookup offers two lookup services: Distributed Hash Tables (DHTs) and replication-based lookup. DHT is employed to construct a structured overlay and provide basic O(log n) lookup service. Furthermore, by taking advantage of DHT routing table, a prefix broadcast scheme is designed to replicate ownership information over the network. Service classification rules are introduced to determine which service should be applied for a certain object. Our simulation shows that, with a slight but acceptable increase in replication bandwidth, DiffLookup can reduce lookup delay significantly by applying the proposed broadcast-based replication to the hottest 10% objects compared to a system without data-oriented differentiation.