Fuzzy cost modeling for peer-to-peer systems

Exiting cost estimation models suffer from several limitations. First, static cost model is not capable of reflecting real-time situations. Second, dynamic cost model is not scalable due to its extensive probe queries. Third, these models are not designed for ad-hoc systems such as P2P, since dynamism of peers is not taken into consideration. In this paper, first, we propose a progressive "push-based" remote cost monitoring approach. We derive a generic static cost model from conventional static approach. Agents will be sent to remote hosts with a generic cost model and epsilons (ε) indicating the acceptable magnitude of cost change, i.e., percentage of coefficient changed. An update will be sent (pushed) to original host once the magnitude of the cost changes exceeds. Second, we introduce a fuzzy cost evaluation metric in additional to traditional evaluation criteria for handling the dynamism of P2P systems. This metric gives a confident measurement of a peer's reliability.