A PnP Scheduling Algorithm and Cache Replacement Algorithm Simulation Platform for Web Server Cluster

Web server cluster has been widely used to improve web server´s performance. In order to help web providers select the appropriate pair of scheduling algorithm and cache replacement algorithm, and to help researchers evaluate new scheduling algorithm or cache replacement algorithm under different client access patterns, this paper designs and implements a trace-driven scheduling algorithm and cache replacement algorithm simulation platform based on JavaSim for web server cluster, called WSCSim. It models the serving time of static and dynamic requests respectively according to their deferent traits, supports traces of different formats, and can simulate complicated algorithms for Java´s powerful function. In WSCSim, trace parser, distribution, scheduling algorithm and cache replacement algorithm are extensible; therefore user can add new components to the platform. Especially, Java interface and Java dynamic proxy technique are used to guarantee the Plug and Play (PnP) characteristic of these extensible components. Simulation tests show the feasibility and validity of WSCSim.