The Improved Redundant Delay Time-Based (IRDTB) Algorithm to Perform Computation Type Application Processes in Heterogeneous Server Clusters

Abstract

In fault-tolerant information systems, application processes have tobe reliably performed in presence of server faults. Server clustersystems are widely used to realize not only high performance but alsofault-tolerant service. In order to reliably perform applicationprocesses, multiple replicas of each application process are performedon multiple servers in a server cluster system. On the other hand, thelarger amount of electric energy is consumed in a server clustersystem since multiple replicas of each application process areperformed on multiple servers. The redundant delay time based (RDTB) algorithm is discussed to select multiple servers to redundantlyperform each application process in a homogeneous server cluster sothat the total energy consumption of the server cluster can bereduced. In a homogeneous cluster, every server follows the samecomputation model and power consumption model. On the other hand, servers follow different types of computation models and powerconsumption models in a heterogeneous server cluster. Hence, a loadbalancer cannot precisely estimate the processing load and energyconsumption of each server in a heterogeneous server cluster by theRDTB algorithm. In this paper, we propose an improved RDTB (IRDTB) algorithm to select multiple servers for redundantly performing eachapplication process so that the total energy consumption of a servercluster and response time of each process in a heterogeneous servercluster can be reduced. We evaluate the IRDTB algorithm compared withthe RDTB algorithm in a heterogeneous server cluster. In theevaluation, we show the average total energy consumption of aheterogeneous server cluster in the IRDTB algorithm can be reducedmaximum 44% of the RDTB algorithm.