Energy Proportional Datacenter Networks
Venue
Proceedings of the International Symposium on Computer Architecture, ACM (2010), pp. 338-347
Publication Year
2010
Authors
Dennis Abts, Mike Marty, Philip Wells, Peter Klausler, Hong Liu
BibTeX
Abstract
Numerous studies have shown that datacenter computers rarely operate at full
utilization, leading to a number of proposals for creating servers that are energy
proportional with respect to the computation that they are performing. In this
paper, we show that as servers themselves become more energy proportional, the
datacenter network can become a significant fraction (up to 50%) of cluster power.
In this paper we propose several ways to design a high-performance datacenter
network whose power consumption is more proportional to the amount of traffic it is
moving --- that is, we propose energy proportional datacenter networks. We first
show that a flattened butterfly topology itself is inherently more power efficient
than the other commonly proposed topology for high-performance datacenter networks.
We then exploit the characteristics of modern plesiochronous links to adjust their
power and performance envelopes dynamically. Using a network simulator, driven by
both synthetic workloads and production datacenter traces, we characterize and
understand design tradeoffs, and demonstrate an 85% reduction in power --- which
approaches the ideal energy-proportionality of the network. Our results also
demonstrate two challenges for the designers of future network switches: 1) We show
that there is a significant power advantage to having independent control of each
unidirectional channel comprising a network link, since many traffic patterns show
very asymmetric use, and 2) system designers should work to optimize the high-speed
channel designs to be more energy efficient by choosing optimal data rate and
equalization technology. Given these assumptions, we demonstrate that energy
proportional datacenter communication is indeed possible.
