Multiple coherence and coordinated checkpointing protocols for DSM systems

In this article, we address two important issues in DSM research: improving performance and providing reliability. To improve performance, we designed a low-overhead multiple coherence protocol mechanism and to augment the reliability of the system, we propose a coordinated checkpointing/recovery mechanism. Both mechanisms were implemented and incorporated in JIAJIA, a DSM system that implements scope consistency with a write-invalidate protocol. Our results on an eight machine cluster with some popular benchmarks show, for the multiple coherence protocol strategy, a significant reduction on the number of messages exchanged, leading to better performance results. Also, our results for the checkpointing strategy show that the overhead introduced in failure-free executions is small when considering the benefits obtained.