Scalable load balancing on distributed web servers using mobile agents

摘要

Distributed web servers on the immensely expanding Internet require high scalability and availability to provide efficient services to millions of clients on the web. To provide rapid responses to enormous number of client requests, load balancing is an important technique to evenly distribute the requests to web servers. In this paper, we propose a framework called Mobile Agent based LoaD balancing (MALD) that uses mobile agents technology to implement scalable load balancing on distributed web servers. The web servers can dispatch mobile agents to collect system-wide load information and accomplish load redistribution on all servers. Various load-balancing policies can be incorporated with versatile mobile agents in the framework. Compared with the traditional message-passing-based load-balancing methods, the mobile-agent-based approaches have the merits of high flexibility, low network traffic and high asynchrony. The performance evaluation demonstrates that the MALD framework provides a foundation to develop efficient load-balancing schemes on wide range of web server systems from cluster to the Internet.