Dynamic Clusters of Servers to Reduce Total Power Consumption

Electric power consumed by servers has to be reduced in order to realize green societies. A server has to be selected in a cluster of servers so that the total power consumption can be reduced. We consider computation (CP) and storage (ST) types of application processes performed on servers in this paper, where CPU and storage drives are mainly used, respectively. In our previous studies, the energy-aware (EA) algorithm is discussed to select a server in a cluster of servers for each request so that the total power consumption of the servers can be reduced. However, an idle server consumes electric power even if no process is performed. In this paper, we discuss a dynamic energy-aware, heterogeneous (DEA-H) cluster. Here, only servers required to perform request processes but no idle servers are included in each cluster. In a DEA-H cluster, servers are selected in a server pool if the traffic increases and idle servers leave for the server pool if the traffic decreases. A server for each request is selected in a heterogeneous DEA cluster so that the total power consumption of servers can be reduced. We evaluate the DEA algorithm on a heterogeneous cluster (DEA-H) in terms of the total power consumption and average execution time.