Greening File Distribution: Centralized or Distributed?

TL;DR

This paper investigates energy-efficient file distribution methods, demonstrating that collaborative peer-to-peer schemes can significantly reduce energy consumption compared to centralized approaches, especially in heterogeneous and realistic network scenarios.

Contribution

It introduces the first approach to energy efficiency in file distribution, proving NP-hardness, deriving bounds, and designing algorithms that outperform centralized schemes in energy savings.

Findings

Collaborative p2p schemes save up to 50% energy compared to centralized methods.

Energy minimization problem is NP-hard in heterogeneous settings.

Algorithms achieve tight bounds and are effective in realistic network conditions.

Abstract

Despite file-distribution applications are responsible for a major portion of the current Internet traffic, so far little effort has been dedicated to study file distribution from the point of view of energy efficiency. In this paper, we present a first approach at the problem of energy efficiency for file distribution. Specifically, we first demonstrate that the general problem of minimizing energy consumption in file distribution in heterogeneous settings is NP-hard. For homogeneous settings, we derive tight lower bounds on energy consumption, and we design a family of algorithms that achieve these bounds. Our results prove that collaborative p2p schemes achieve up to 50% energy savings with respect to the best available centralized file distribution scheme. Through simulation, we demonstrate that in more realistic cases (e.g., considering network congestion, and link variability across hosts) we validate this observation, since our collaborative algorithms always achieve significant energy savings with respect to the power consumption of centralized file distribution systems.