Work-in-Progress: Optimal Checkpointing Strategy for Real-time Systems with Both Logical and Timing Correctness

This paper proposes an optimal checkpoint scheme for fault resilience in real-time systems, in which we consider both logical consistency and timing correctness. First, we partition message-passing processes into a directed acyclic graph (DAG) considering their dependencies, where the logical consistency of checkpoints is guaranteed. Then, we find the critical path of the DAG, which is the longest path performed in sequence. Next, we analyze the optimal checkpoint strategy on the critical path where the overall execution time (including checkpointing overhead) is minimized. When a fault is detected, the system rolls back to the nearest valid checkpoint for recovery. The optimal number of checkpoints and their intervals are derived by the algorithm.