Unleash Stranded Power in Data Centers with Rack Packing

Lakshmi Ganesh, Jie Liu, Suman Nath, Galen Reeves, and Feng Zhao

Abstract

Data center infrastructures are highly underutilized on average. Typically, a data center manager computes

the number of servers his facility can host by dividing the total power capacity of each rack by an assigned “peak

power rating” for each server. However, this scheme suffers from the weakness of all static provisioning schemes

– it does not account for the variability of load on the servers. We propose an algorithm that studies the power

consumption behavior of the servers over time and suggests optimal ways to combine them in racks to maximize

rack power utilization. The server placement problem is a version of vector bin packing, and our solution –

RackPacker – approximates a near-optimal solution efficiently using a number of domain-specific optimizations.

One of the central insights we use is that the different servers hosting a single application typically show strongly

correlated, but often somewhat time-shifted, power consumption behavior. Hence, we find servers that show anticorrelated,

or strongly time-shifted behavior and pack them together to maximize rack utilization. Our initial

experiments with RackPacker show substantially superior results than static packing.

Details

Publication typeTechReport
NumberMSR-TR-2009-21
PublisherMicrosoft
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