Abstract: Static Segregation Scheduling Policy（SSSP） can’t allocate server resources efficiently.Proposed Dynamic Segregation Scheduling Policy（DSSP） uses different servers to serve static and dynamic requests，schedules static and dynamic requests in unit of requested files and user sessions respectively.The dispatcher monitors the status of back-end servers，and classifies them into three categories：lightly loaded，heavily loaded and over loaded.Lightly loaded servers continue to accept new request units，heavily loaded servers don’t accept new request units，but keep on serving accepted request units，over loaded servers transfer some of their accepted request units to lightly loaded servers.Experiment shows that DSSP is better than SSSP.

Key words: Web cluster, request dispatch, schedule policy

摘要： 静态分离式调度策略（SSSP）不能有效地分配服务器资源。动态分离式调度策略（DSSP）对静态请求和动态请求分别以请求的文件和用户会话为单元进行调度。请求分发器监测后端服务器的状态，按资源使用情况将服务器区分为轻载、重载和过载，轻载服务器可以接收新的请求单元，重载服务器不接收新请求单元，但继续为已接收的请求单元服务，过载服务器迁移部分请求单元到轻载服务器。试验结果表明，DSSP的效率明显优于SSSP。

关键词: Web集群, 请求分发, 调度策略