Energy-efficient cloud data center with fair service level agreement for green computing

More and more cloud data centers provide numerous cloud computing services. However, how to meet customer needs, improve efficiency and reduce costs are important issues that cloud service providers must deal with. For customers, it is very important to consider the quality of service requirements provided by the data center providing public cloud services. Besides, data center operators should consider how to reduce energy consumption. Therefore, for these important issues, we propose a possible balance between service quality and energy conservation strategy. We find the relationship between the minimal service resources and the required level of services. Under conditions consistent with the SLA, our strategy quantifies the quality of service and calculates the required computing resources according to changes in workload to achieve an energy-saving goal. Also, the policy approximate function is derived and can achieve efficient decision-made goals.