The Delay Time-Based (DTB) Algorithm for Energy-Efficient Server Cluster Systems

The improved power consumption laxity-based (IPCLB) algorithm is discussed to select one of servers so that the total power consumption of a cluster can be reduced. However, a load balancer has to collect a state of every current process on servers of a cluster to calculate the estimated power consumption of each server. In addition, it is difficult to precisely estimate the power consumption of each server since the state of each process on the server is changed during the estimation. Especially, a process might terminate before the termination time is estimated if the computation time of the process is shorter than the communication delay time between the load balancer and the server. In this paper, we assume the computation time of each process is shorter than the communication delay time. Then, we propose a delay time-based (DTB) algorithm to select a server for each request process so that the total power consumption of a cluster to perform processes on the server can be reduced. In the DTB algorithm, it is not necessary to collect a state of every process on each server to estimate the power consumption laxity. In addition, the minimum computation time of a process is not required to be a priori defined in the DTB algorithm.