ABSTRACT
The demand in research in energy efficiency in large-scale systems is supported by several incentives [12,31,35], including financial incentives by government or institutions for energy-efficient industries/companies [29]. Indeed, studies like [9] report that IT consumption accounts for between 5% and 10% of the global growing electricity demand, and for a mere 2% of the energy while data centers alone account for 14% of the ICT footprint. It is projected that by 2020 the energy demand of data centers will represent 18% of the ICT footprint, the carbon footprint rising at an annual 7% pace, doubling between 2007 and 2020 [39]. The last 5 years have witnessed the increase of research focusing especially in energy reduction. While being a major concern in embedded systems for decades, the problem is quite new in large-scale infrastructures where performances have been for long the sole parameters to optimize. The motivation comes from two complementary concerns: First, the electrical cost of running such infrastructure is equivalent nowadays with the purchase costs of the equipment during a 4-year usage [27]. Second, electricity providers are not always able to deliver the needed power to run themachines, capping the amount of electricity delivered to one particular client.
