Cloud Computing: Survey on Energy Efficiency

Cloud Computing is today´s most emphasized Information and Communications Technology (ICT) paradigm that is directly or indirectly used by almost every online user. However, such a great significance comes with a support of a great infrastructure that includes large data centers comprising thousands of server units and other supporting equipment. Their share in power consumption generates between 1.1% and 1.5% of the total electricity use worldwide, and is projected to rise even more. Such alarming numbers demand rethinking the energy efficiency of such infrastructures. However, before making any changes to the infrastructure, an analysis of the current status is required.<br> In this paper we perform a comprehensive analysis of an infrastructure supporting the Cloud Computing paradigm with regards to the energy efficiency. First, we define a systematic approach for analyzing energy efficiency of most important data center domains, including server and network equipment, as well as cloud management systems and appliances consisting of a software utilized by end users. Secondly, we utilize this approach for analyzing available scientific and industrial literature on state of the art practices in data centers and its equipment. Finally, we extract existing challenges and highlight future research directions.