Energy-Efficient and Fault-Tolerant Distributed Mobile Execution

Although battery capacities keep increasing, the execution demands of modern mobile devices continue to outstrip their battery lives. As a result, battery life is bound to remain a key constraining factor in the design of mobile applications. To save battery power, mobile applications are often partitioned to offload parts of their execution to a remote server. However, partitioning an application renders it unusable in the face of network outages. In this paper, we present a novel approach that reduces the energy consumption of mobile applications through server offloading without partitioning. The functionality that consumes energy heavily is executed in the cloud, with the program's state check pointed and transferred across the mobile device and the cloud. Our approach is portable, as it introduces the offloading functionality through byte code enhancement, without any changes to the runtime system. The check pointed state's size is minimized through program analysis. In the case of a network outage, the offloading interrupts and the application reverts to executing locally from the latest checkpoint. Our case studies demonstrate how our approach can reduce energy consumption for third-party Android applications. Transformed through our approach, the applications consume between 30% and 60% fewer Joules than their original versions. Our results indicate that portable offloading can improve the battery life of modern mobile applications while maintaining their resilience to network outages.