AESOP home

Publications

Fluid analysis of energy consumption using rewards in massively parallel Markov models

Anton Stefanek, Richard Hayden, Jeremy T. Bradley

Conference or Workshop Paper
ICPE 2011, 2nd ACM/SPEC International Conference on Performance Engineering, March 14-16, 2011, Karlsruhe, Germany
March, 2011
pp.121–131
ACM
ISBN 978-1-4503-0695-9
DOI 10.1145/1958746.1958767
Abstract

Capturing energy consumption directly from a stochastic behavioural model is a computationally expensive process. Using a so-called fluid analysis technique we are able to access accumulated reward measures in much larger scale stochastic systems than has been previously possible. These accumulated rewards are ideal for deriving energy and power consumption from stochastic process models. In previous work, it has been shown how to derive a set of ordinary differential equations (ODEs) whose solutions approximate the moments of component counts in a continuous-time Markov chain (CTMC) described in a stochastic process algebra. In this paper, we show how to extend the method to provide rapid access to moments of accumulated rewards in CTMCs. In addition to measuring the amount of energy used by a system, we are also interested in the time taken to reach a particular level of energy consumption. In reward terms, this is a so-called completion time. In this paper, we are able to use higher moments of rewards to give us access to completion time distributions.

We demonstrate the technique on a model of energy consumption in a client--server system with server failure and hibernation. Moreover, we are able to use these new and rapid techniques to capture the trade-off between energy consumption and service level agreement (SLA) compliance. We use a standard optimisation approach to find the precise configuration of the system which minimises the energy consumption while satisfying an operational response-time quantile.

PDF of full publication (571.2 kilobytes)
(need help viewing PDF files?)
PDF of presentation slides (1 megabyte)

Information from pubs.doc.ic.ac.uk/fluid-energy-rewards.