Optimizing average job response time via decentralized probabilistic job dispatching in heterogeneous multiple computer systems

In this paper, we study decentralized probabilistic job dispatching and load balancing strategies which optimize the performance of heterogeneous multiple computer systems. We present a model to study a heterogeneous multiple computer system with a decentralized stochastic job dispatching mechanism, where nodes are treated as M/G/1 servers. We discuss a way to implement a virtual centralized job dispatcher using a distributed control mechanism. We derive closed form solutions for optimal job dispatching probabilities which minimize the average job response time, when all nodes have an identical coefficient of variation for job execution times. We also generalize the results to the case where nodes have different coefficients of variation for job execution times.