A two-layer model for improving the energy efficiency of file sharing peer-to-peer networks

摘要

As peer-to-peer networks gather and share large sets of computing resources, their aggregate energy consumptionrnis an important problem to be addressed, given the economic and environmental impact of energyrnproduction and use. This is particularly true for file sharing peer-to-peer networks, considered the vast numberrnof nodes participating to these systems. To address such problem, this paper proposes a peer-to-peerrnfile sharing model organized in two logical layers. The lower layer is composed of a set of peers providingrnthe files to be shared. The upper layer includes a set of super peers organized to form a distributedrnhash table, whose purpose is indexing files and peers, including their availability status. Following a sleepand-rnwake approach, energy saving is achieved by letting peers cyclically switch between normal and sleeprnmodes, where the time passed in normal mode by a peer depends on the number of files it provides. Anrnenergy-saving algorithm and an associated file search and retrieval strategy are proposed within this model.rnSimulation results show that more than 50% of energy can be saved using the proposed model and that morernthan 80% of file downloads start with no additional delay compared with a network in which all peers arernalways powered on.