Checkpointing In Parallel State-Machine Replication

State-machine replication is a popular approach to building fault-tolerant systems, which relies on the sequential execution of commands to guarantee strong consistency. Sequential execution, however, threatens performance. Recently, several proposals have suggested parallelizing the execution model of the replicas to enhance state-machine replication's performance. Despite their success in accomplishing high performance, the implications of these models on checkpointing and recovery is mostly left unaddressed. In this paper, we focus on the checkpointing problem in the context of Parallel State-Machine Replication. We propose two novel algorithms and assess them through simulation and a real implementation.