New content-aware request distribution policies in web clusters providing multiple services

Due to the explosive growth of the Internet and increasing service demands from all around the world, the cluster-based system that consists of one request-dispatching server and several request-handling servers has become a cost-effective way to serve the huge amount of service demands. Nowadays, Web servers have to handle more complex types of requests since requests from clients may be mixed with dynamic Web pages, database processing, or multimedia stream data. Therefore, a Web cluster should be designed with intelligent request dispatching policies for supporting various types of service requests. In this paper, we have proposed two new content-aware request distribution policies named Locality-Aware Request Distribution with Replication and Classification (LARD/RC) and Grouped Client-Aware Policy (GCAP) to dispatch requests efficiently in Web clusters providing multiple types of services and running in homogeneous or heterogeneous environments. We have implemented our proposed policies in the LVS-CAD web cluster that can efficiently perform content-aware request dispatching. Performance evaluation shows that our proposed LARD/RC and GCAP policies could dispatch requests of different types to proper back-end servers in a more efficient way to utilize system resources than the other existing policies in both homogeneous and heterogeneous environments.