Recent Trends in Energy-Efficient Cloud Computing

Almost every online user directly or indirectly uses cloud computing, which is the most promising information and communication technology (ICT) paradigm. However, cloud computing's ultrascale size requires large datacenters comprising thousands of servers and other supporting equipment. The power consumption share of such infrastructures reaches 1.1 percent to 1.5 percent of the total electricity use worldwide, and is projected to rise even more. In this article, the authors describe recent trends in cloud computing regarding the energy efficiency of its supporting infrastructure. They present state-of-the-art approaches found in literature and in practice covering servers, networking, cloud management systems, and appliances (user software). They also describe benefits and trade-offs when applying energy-efficiency techniques, and discuss existing challenges and future research directions.