A weighted-fair-queuing (WFQ)-based dynamic request scheduling approach in a multi-core system

A popular website is expected to simultaneously deal with a large number of dynamic requests in the reasonable mean response time. The performance of websites mainly depends on hardware performance and the processing strategy of dynamic requests. In order to improve the hardware performance, more and more web servers are adopting multi-core CPUs. Moreover, the scheduling algorithm of requests on the first-come–first-served (FCFS) basis is still utilized. Although FCFS is a reasonable and fair strategy for request sequences, it takes into account neither the distribution of the dynamic request service times nor the characteristics of multi-core CPUs. In the present paper, in order to solve the above-mentioned problems, a new dynamic request scheduling approach is proposed. The new scheduling approach, according to the distribution of the dynamic request service time, schedules the dynamic requests based on a weighted-fair-queuing (WFQ) system, and exploits the performance of multi-core CPUs by means of the hard affinity method in the O/S. Simulation experiments have been done to evaluate the new scheduling approach, and the results obtained prove that the new scheduling approach could eliminate the ping-pong effect and efficiently reduce the mean response time.

► We propose a dynamic request scheduling approach for multi-core web servers.
► The approach eliminates the ping-pong effect in multi-core CPUs and overcomes the limits of the FCFS scheduling policy.
► Simulation results prove that the approach proposed can reduce the mean response time.