Protocol-Aware Recovery for Consensus-Based Distributed Storage.

We introduce protocol-aware recovery (Par), a new approach that exploits protocol-specific knowledge to correctly recover from storage faults in distributed systems. We demonstrate the efficacy of Par through the design and implementation of corruption-tolerant replication (Ctrl), a Par mechanism specific to replicated state machine (RSM) systems. We experimentally show that the Ctrl 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 Ctrl versions achieve this reliability with little performance overheads.