QoS-aware load balancing algorithm for globally distributed Web systems

The use of Web servers is growing tremendously, but their performance and reliability have not improved at the same rate. Users of highly popular Web sites may experience long delays when accessing information. We present a two-level distributed Web architecture that uses our QoS-aware load-balancing algorithm to significantly reduce the mean response times by taking into account both stale load information and content-based scheduling when choosing a server for a incoming request for globally distributed Web systems. To achieve better end-to-end quality of service (QoS), different classes of service (CoS) of the customers are considered as one parameter in the load-balancing algorithm.