Analysis of dynamic load balancing strategies using a combination of stochastic petri nets and queueing networks

Abstract

This paper is concerned with the analytical evaluation of two well known dynamic load balancing strategies, namely, shortest queue routing (SQR) and shortest expected delay routing (SEDR). We overcome the limitations of existing analysis methodologies, using a well known hybrid performance model that combines generalized stochastic Petri nets and product form queueing networks. Our methodology is applicable to both open queueing network and closed queueing network models of load balancing in distributed computing systems. The results show that for homogeneous distributed systems, SQR outperforms all other policies. For heterogeneous systems, SEDR surprisingly performs worse than SQR at low levels of imbalance in loads. However, with increase in imbalance in load, SEDR expectedly performs better than SQR.