Ushijima Kazuo

Evaluation of process scheduling mechanism for a Web server based on its behavior while executing

Traditional operating systems control the sharing of the processor resources among processes using a fixed scheduling policy based on the utilization of a computer system such as real time or timesharing systems. Since the control over the processor allocation is based on a fixed policy, not based on process execution behavior, this can hinder an effective use of a processor or can extend the processing time of a process unnecessarily. Thus, we proposed a couple of process scheduling policies which respond to process execution behavior. One of these policies is the policy for improving a Web servers response time. This policy controls multiple processes of a Web server by adjusting the execution of these processes according to their predicted behavior. We evaluated the performance of a Web server using this policy in simple cases. We evaluate the performance of a Web server when it is busy which is likely to be a realistic case. This could be the case in which it is most desirable to improve the response time of a Web server. Our experimental results show that the mean response times are improved greatly (up to 33.8% in the best case). They also show that the scheduling parameter is effectively predicted and updated by our mechanism based on the Web servers execution behavior.