Energy consumption in data centers with deterministic setup times

Kara, Aytaç
Data centers, which are networks consisting of thousands of computers, are central objects in the global computation infrastructure. Typical data centers today may consume as much electricity as a small town. Thus, it is of interest to build models of these centers that allow one to study / optimize their energy usage. One of the models for the energy usage based on queueng theory is the one developed in “Exact Solutions for M/M/c/Setup Queues” by Tuan Phung-Duc. The same work carries out a stationary analysis of the developed model to compute the long term average energy cost per unit time. The model of Phung-Duc assumes that the data center consists of c servers and that the servers are in one of the following three modes: running, stopped or in setup. The setup mode is assumed to last a random exponentially distributed time. We modify this model as follows: we replace exponentially distributed setup times with a fixed deterministic setup time. We call the resulting model M/M/c/dSetup: We approximate the long term average cost per unit time via simulation and compare this cost with that of the M/M/c/Setup system. Our main finding are as follows: the average energy cost of these systems provide good approximations of one another. Secondly, the average energy cost of the M/M/c/Setup system provides a lower bound for that of the M/M/c/dSetup system.  
Citation Formats
A. Kara, “Energy consumption in data centers with deterministic setup times,” M.S. - Master of Science, Middle East Technical University, 2017.