Competitive Analysis of Task Scheduling Algorithms on a Fault-Prone Machine and the Impact of Resource Augmentation

Abstract

Reliable task execution in machines that are prone to unpredictable crashes and restarts is challenging and of high importance. However, not much work exists on the worst case analysis of such systems. In this paper, we analyze the fault-tolerant properties of four popular scheduling algorithms: Longest In System (LIS), Shortest In System (SIS), Largest Processing Time (LPT) and Shortest Processing Time (SPT), under worst case scenarios on a fault-prone machine. We use three metrics for the evaluation and comparison of their competitive performance, namely, completed time, pending time and latency. We also investigate the effect of resource augmentation in their performance, by increasing the speed of the machine. To do so, we compare the behavior of the algorithms for different speed intervals and show that between LIS, SIS and SPT there is no clear winner with respect to all the three considered metrics, while LPT is not better than SPT.