Performance evaluation of a threshold policy for scheduling readers and writers

摘要

An analysis of a threshold policy for scheduling readers and writers in a multiserver system and a comparison of its performance with the first-come, first-served (FCFS) policy are presented. The threshold fastest emptying (FTE) policy is analyzed in a system with writer arrivals and an infinite backlog of readers using a Markovian model as well as a vacationing server model to yield closed-form expressions for the mean writer response time and the reader throughput. The maximum throughput achieved by the TFE policy is shown to be an increasing function of K, the threshold on the number of writers in the system, which even at K=1 exceeds the maximum throughput achieved by FCFS. In a system with reader and writer arrivals (nonsaturated system), simulation is used to study and compare the mean response time for the FCFS and the TFE policies.