Value driven load balancing

To date, the study of dispatching or load balancing in server farms has primarily focused on the minimization ofresponse time. Server farms are typically modeled by a front-end router that employs a dispatching policy to routejobs to one of several servers, with each server scheduling all the jobs in its queue via Processor-Sharing. However,the common assumption has been that all jobs are equally important or valuable, in that they are equally sensitiveto delay. Our work departs from this assumption: we model each arrival as having a randomly distributed valueparameter, independent of the arrival’s service requirement (job size). Given such value heterogeneity, the correctmetric is no longer the minimization or response time, but rather, the minimization of value-weighted response time.In this context, we ask “what is a good dispatching policy to minimize the value-weighted response time metric?”We propose a number of new dispatching policies that are motivated by the goal of minimizing the value-weightedresponse time. Via a combination of exact analysis, asymptotic analysis, and simulation, we are able to deduce manyunexpected results regarding dispatching.