Implementation of Load Balancing in Distributed Web Server
Zhang Zhongneng · Jisuanji gongcheng · 2003
An implementation of a prototype scalable Web server is presented and evaluated in this paper. The prototype consists of a load-balanced cluster of hosts that collectively accept and service TCP connections. The host IP addresses are advertised using the Round Robin DNS technique, allowing any host to receive requests from any client. Once a client attempts to establish a TCP connection with one of the hosts, a decision is made as to whether or not the connection should be redirected to a different host. The low-overhead IP is used encapsulation within IP is used to redirect TCP connections. Each host keeps load information about the remaining hosts in the system, which is maintained using periodic multicast amongst the cluster hosts. Performance measurements suggest that the redirection using system state outperforms both pure RR-DNS and the stateless.