A study of mutable checkpointing and related algorithms

Mutable Checkpointing algorithms (MC), [7], [8], [9], stand for snapshot algorithms that take checkpoints of processes with causally induced dependencies to the initiating process, only. They classify as coordinated snapshot algorithms with communication induced checkpointing. To specify and verify such algorithms formally, we introduce a formal framework in which their operational semantics can easily be expressed. Within this framework correctness of the algorithms follows from an invariant which explains how snapshots are incrementally built up. For MC and the related blocking queue algorithms of [26], [27] some adaptations are required as they take a partial snapshot, only. However, both can be proven in the given framework and in this way we equip them with a direct, constructive consistency proof.