Parallel Pull-Based LRU : a New Request Distribution Algorithm for Large Scale SCI Clustered Web Caches

The SIRAC laboratory has developed SciFS, a Distrib- uted Shared Memory (DSM) tightly integrated with the Linux operating system kernel, that exploits the high performance and remote addressing capabilities of SCI (Scalable Coherent Interface) networks. We experiment with using SciFS to build large scale clustered web caches. An efficient DSM does not only provide a fast and large data storage space, but it also allows the design of new algorithms to handle user requests. * We propose a clustered web cache prototype with a new request distribution algorithm, called PPBL (Parallel Pull-Based LRU), especially designed for use with a DSM system. Unlike other distribution algorithms the decision is distributed over all nodes thus providing better scal- ability. In this short paper, we only present PPBL princi- ples but additional information can be found on our web site at http://sci-serv.inrialpes.fr.