GreenSLAs: Supporting energy-efficiency through contracts

Abstract

Outsourcing services from local or personal devices to data centers or the cloud is an ongoing trend in information technology. This trend has led to the expansion of the IT service business and, to a dramatic increase of energy consumption in data centers. One of the objectives of GreenIT is to stop or even reverse this development. Many technical approaches to save energy during the operational phase of a data center are currently being proposed. Unfortunately, a reduction of energy consumption may have a negative impact onto a customer's perceived quality-of-service as denoted in service level agreements (SLAs). Energy aware "GreenSLAs" can help counteracting this dilemma by extending a data center's scope to pursue energy saving measures at runtime. This paper discusses the idea and first empirical results regarding the use of GreenSLAs to balance performance, time, cost, and energy by including semantic information into executable SLAs. © 2012 Springer-Verlag.