THE EFFECT OF INCREASING ROUTING CHOICE ON RESOURCE POOLING

We consider a network of N identical ./M/1 or ./M/infinity queues. The re are two types of arriving customers, those that have no routing cho ice, and those that first pick r queues at random, and are then routed to the least busy of those queues. We derive the limiting distributio n of queue lengths as N --> infinity, and investigate how this distrib ution varies with r. We show that even a small amount of routing choic e can lead to substantial gains in performance through resource poolin g. We corroborate these conclusions by carrying out some simulations o f a related model, from which the previous model can be derived by an exchangeable queue simplification. We also observe that the exchangeab le queue simplification results in a performance gain for some paramet ers, in contrast to earlier work.