PathFinder: Efficient Lookups and Efficient Search in Peer-to-Peer Networks

Peer-to-Peer networks are divided into two main classes: unstructured and structured. Overlays from the first class are better suited for exhaustive search, whereas those from the second class offer very efficient key-value lookups. In this paper we present a novel overlay, PathFinder , which combines the advantages of both classes within one single overlay for the first time. Our evaluation shows that PathFinder is comparable or even better in terms of lookup and complex query performance than existing peer-to-peer overlays and scales to hundreds of millions of nodes. Peers in PathFinder are arranged as Erdo ̈s Renyi random graph. Consequently, all overlay operations such as key-value lookup, complex queries and main- tenance messages greatly benefit from the short average path length, the high number of alternative paths and the robustness of the underlying random graph topology