An Extended Power Consumption Model for Distributed Applications

The power consumption of information systems, especially servers has to be reduced to realize green eco-society. A client first selects a server in a collection of possible 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 type of application where CPU resource is mainly used in a server. It is critical to discuss how to select a server for each request from clients in order to reduce the total power consumption. The power consumption laxity based (PCLB)algorithm for selecting a server is discussed in this paper, where a server to consume the minimum power to perform a process is selected. In a server, cooling devices like CPU fans consume the electronic power in addition to CPU and other devices. In our previous studies, we assume the cooling devices consume the constant power and propose the simple power consumption model. In the simple power consumption model, if at least one application process is performed on a server, the electric power is maximally consumed on the server. Otherwise, the electric power consumption is minimum. The rotation speed of a fan is controlled in servers based on the temperature of CPU and in the server´s case. Thus, the total power consumption of a server depends on not only the power consumption of computational devices like CPU but also the power consumption of cooling devices like fans. In this paper, we extend the simple power consumption model to take into account the power consumption of cooling devices. We improve the PCLB algorithm based on the extended simple power consumption model.