Energy-Efficient Server Selection Algorithm Based on the Extended Simple Power Consumption Model

In information systems, a client first selects a server in a cluster of servers and issues a request to the server. The request is performed as a process in the server. In this paper, we consider a computation process which mainly consumes CPU resource. Cooling devices like fans consume the electric power in addition to CPU and other devices in a server. The rotation speed of a fan is changed in servers according to the temperature of a server. Thus, the total power consumption of a server depends on not only computational devices like CPU but also cooling devices. The extended simple power consumption (ESPC) model of a server is proposed to perform processes. In this paper, the ESPC model is improved to consider a server with a multi-core CPU. It is critical to discuss how to select a server for each request from clients in order to not only achieve performance objectives but also reduce the total power consumption of a system based on the ESPC model. The improved power consumption laxity based (IPCLB) algorithm for selecting a server is proposed in this paper, which consumes the minimum power to perform the process. We evaluate the ESPC model and the IPCLB algorithm in terms of the power consumption and elapse time in this paper.