Hybrid Power Failure Recovery for Intermittent Computing

Energy harvesting systems rely on either rollback or roll-forward recovery to resume power-interrupted program correctly. However, both recovery schemes have their own inherent drawbacks. To this end, this paper presents RollSwitch, a hybrid power failure recovery scheme that can achieve low-cost yet high-performance intermittent computation for energy harvesting systems. According to the underlying energy harvesting condition, RollSwitch dynamically switches between rollback and roll-forward recovery modes to maximize the performance. In particular, RollSwitch leverages the level of available energy in the capacitor as a proxy for determining the appropriate recovery mode. For this purpose, RollSwitch devises a simple capacitor energy predictor whose outcome governs the recovery mode selection in the near future. The experimental results demonstrate that RollSwitch achieves 15.0% and 19.8% performance gain on average over the state-of-art rollback and roll-forward recovery schemes, respectively.