Evaluating GUESS and non-forwarding peer-to-peer search

Current search techniques over unstructured peer-to-peer networks rely on intelligent forwarding-based techniques to propagate queries to other peers in the network. Forwarding techniques are attractive because they typically require little state and offer robustness to peer failures; however they have inherent performance drawbacks due to the overhead of forwarding and lack of central control. We study GUESS, a nonforwarding search mechanism, as a viable alternative to currently popular forwarding-based mechanisms. We show how non-forwarding mechanisms can be over an order of magnitude more efficient than forwarding mechanisms; however, they must be deployed with care, as a naive implementation can result in highly suboptimal performance, and make them susceptible to hotspots and misbehaving peers.