Power Log'n'Roll: Power-Efficient Localized Rollback for MPI Applications Using Message Logging Protocols

In fault tolerance for parallel and distributed systems, message logging protocols have played a prominent role in the lastthree decades. Such protocols enable local rollback to provide recovery from fail-stop errors. Global rollback techniques can bestraightforward to implement but at times lead to slower recovery than local rollback. Local rollback is more complicated but can offerfaster recovery times. In this work, we study the power and energy efficiency implications of global and local rollback. We propose apower-efficient version of local rollback to reduce power consumption for non-critical, blocked processes, using Dynamic Voltage andFrequency Scaling (DVFS) and clock modulation (CM). Our results for 3 different MPI codes on 2 parallel systems show thatpower-efficient local rollback reduces CPU energy waste up to 50% during the recovery phase, compared to existing global and localrollback techniques, without introducing significant overheads. Furthermore, we show that savings manifest for all blocked processes,which grow linearly with the process count. We estimate that for settings with high recovery overheads the total energy waste ofparallel codes is reduced with the proposed local rollback.