tailieunhanh - ElasticTree: Saving Energy in Data Center Networks - Allan Kaprow, John Cage

I am think- ing here of Allan Kaprow, John Cage, or George Maciunas. They sensed that the depictive arts could not be displaced by any more upheavals from within, any more radical versions of depic- tion or anti-depiction. They came to recognize that there was something about the depictive arts that would not permit an- other art form or art dimension to evolve out of them. The new challenge to western art would be advanced in terms of move- ment and the arts of movement. Cage’s piano concert, 4’33”, first presented in 1952, can be seen as the first explicit statement of this. | ElasticTree Saving Energy in Data Center Networks Brandon Heller Srini Seetharamant Priya Mahadevan0 Yiannis Yiakoumis Puneet Sharma0 Sujata Banerjee0 Nick McKeown Stanford University Palo Alto CA USA t Deutsche Telekom R D Lab Los Altos CA USA 0 Hewlett-Packard Labs Palo Alto CA USA ABSTRACT Networks are a shared resource connecting critical IT infrastructure and the general practice is to always leave them on. Yet meaningful energy savings can result from improving a network s ability to scale up and down as traffic demands ebb and flow. We present ElasticTree a network-wide power1 manager which dynamically adjusts the set of active network elements links and switches to satisfy changing data center traffic loads. We first compare multiple strategies for finding minimum-power network subsets across a range of traffic patterns. We implement and analyze ElasticTree on a prototype testbed built with production OpenFlow switches from three network vendors. Further we examine the trade-offs between energy efficiency performance and robustness with real traces from a production e-commerce website. Our results demonstrate that for data center workloads ElasticTree can save up to 50 of network energy while maintaining the ability to handle traffic surges. Our fast heuristic for computing network subsets enables ElasticTree to scale to data centers containing thousands of nodes. We finish by showing how a network admin might configure ElasticTree to satisfy their needs for performance and fault tolerance while minimizing their network power bill. 1. INTRODUCTION Data centers aim to provide reliable and scalable computing infrastructure for massive Internet services. To achieve these properties they consume huge amounts of energy and the resulting operational costs have spurred interest in improving their efficiency. Most efforts have focused on servers and cooling which account for about 70 of a data center s total power budget. Improvements include better components .