Protocol-Aware Recovery for Consensus-Based Distributed Storage

Abstract

We introduce protocol-aware recovery (P ar ), a new approach that exploits protocol-specific knowledge to correctly recover from storage faults in distributed systems. We demonstrate the efficacy of P ar through the design and implementation of <underline>c</underline>orruption-<underline>t</underline>olerant <underline>r</underline>ep<underline>l</underline>ication (C trl ), a P ar mechanism specific to replicated state machine (RSM) systems. We experimentally show that the C trl versions of two systems, LogCabin and ZooKeeper, safely recover from storage faults and provide high availability, while the unmodified versions can lose data or become unavailable. We also show that the C trl versions achieve this reliability with little performance overheads.