TR-96-26: The Effect of Scheduling Discipline on Dynamic Load Sharing in Heterogeneous Distributed Systems

Dynamic load sharing policies have been extensively studied. Most of the previous studies have assumed a homogeneous distributed system with a first-come-first-served (FCFS) node scheduling policy. In addition, job service times and inter-arrival times are assumed to be exponentially distributed. In this paper, we study the impact of these assumptions on the performance of sender-initiated and receiver-initiated dynamic load sharing policies in heterogeneous distributed systems. We consider two node scheduling policies – first-come/first-served (FCFS) and round robin (RR) policies. Furthermore, the impact of variance in inter-arrival times and job service times is studied. Our results show that, even in heterogeneous distributed systems, when the round robin node scheduling policy is used, sender-initiated policy is better than the receiver-initiated policy unless the variance in job service times is low. This is an important observation as most workstations use a scheduling policy similar to the round robin policy considered here.

TR-96-26.pdf