Approaches Towards Energy-Efficiency in the Cloud for Emerging Markets

With the growing importance of the cloud computing paradigm, it is a challenge for cloud providers to keep the operational costs of the data centers in check, especially in the emerging markets, alongside catering to the customers´ needs. It becomes essential to increase the operational efficiency of the data centers to be able to maximize VM (Virtual machine) offerings at minimal cost. To that end, energy-efficiency of the servers plays a critical role, as they influence the electrical and the cooling costs which constitute a major part of the total cost involved in the operation of a data center. Power-savings can be achieved at several different levels in a system: processors, memory, devices, and system-wide (involving powering down multiple components of a host all at once). At the processors level, depending on the workload trends, we can exploit technologies like DVFS (Dynamic Voltage and Frequency Scaling) or P-states when the CPU is running, and CPU sleep states (C-states) when the CPU is idle, to save power. Memory standards such as DDR3 have provisions for putting idle memory banks into low-power states. At the devices level, individual devices can be put into low-power states, controlled and co-ordinated by a run-time power management framework in the Operating System. This paper outlines the state-of-the-art in power- management technology on server hardware and describes how these raw features can be abstracted into a set of energy policies. We then explain how these policies or energy-profiles can be used to run a cloud datacener energy efficiently. Further, this paper also highlights some of the challenges involved in running cloud infrastructures in the emerging markets optimally despite some unique energy constraints.