A Request Distribution Algorithm for Web Server Cluster
With the explosively increasing of web-based applications' workloads, Web server cluster encounters challenge in response time for requests. Request distribution among servers in web server cluster is the key to address such challenge, especially under heavy workloads. In this paper, the authors propose a new request distribution algorithm named LLAC (Least Load Active Cache) for load balancing switch in web server cluster. The goal of LLAC is to improve the cache hit rate and reduce response time. Packets are parsed in IP level, and back-end servers are notified to cache hot files using link change technology, neither changing URL information nor modifying the service program. This avoids switching overhead between user mode and kernel mode.