AN EFFICIENT LOAD BALANCING ALGORITHM FOR WEB SERVER CLUSTSERS: MOLL (MIGRATION-OPTIMIZED LEAST LOADED) LOAD-BALANCING ALGORITHM

摘要

This paper presents our ongoing research on optimizing the response time in clustered web servers. A new efficient load-balancing algorithm, Migration-Optimized Least Loaded (MOLL) algorithm, is proposed and its performance was evaluated using simulation experiment method. MOLL is new in a sense that it combines two significant factors in load balancing, server workload and session migration delay. MOLL is efficient in a sense that it results in better response time than major existing load-balancing algorithms. For low server workload, MOLL reduced response time from round robin, random, last visited and least loaded algorithms by 37.9, 36.9, 19.4 and 34.9%, respectively. They were reduced by 52.1, 51.7, 40.7, and 12.3% for high server workload. It was learned that balancing between server workload and session migration delay would be an efficient technique to optimize response time for clustered web servers.