Detection and Analysis of Performance Deterioration in Mobile Offloading System

Offloading is an advanced technique to improve the performance of mobile devices by migrating heavy computation to remote powerful servers. The completion of an offloading task requires a reliable network connection and a stable remote server. Therefore, the system performance is determined by the network quality and the server service rate. In this paper, we present an experiment to measure the system performance using task completion time as metric. We detect that system performance is not stable at some moments. For identifying the cause of performance deterioration, we analyse the impact of server and network. It is well known that software aging is a common phenomenon in computer systems, which may cause frequent software faults and finally result in system outage. As rejuvenation is used to counteract software aging, through our experiment, we observed the impact of periodical rejuvenation on the offloading system. Although the rejuvenation process impairs the system performance temporarily, long-term stability of the server is guaranteed. We further explore the impact of poor network quality, which is the main factor degrading the system performance. To improve the system performance, we proved that restart is an efficient mechanism in theory.