On characteristics of DEF communication-induced checkpointing protocols

Domino-Effect Freedom (DEF) is a property stating that unbounded, cascading rollback propagation will not occur during the process of finding a consistent global checkpoint. DEF checkpointing protocols can be classified into two different categories: index-based and model-based. An index-based protocol timestamps local checkpoints with sequence numbers for achieving consistency, while a model-based one prohibits the formation of particular checkpoint and communication patterns in the execution. In this paper we explore several characteristics of communication-induced checkpointing protocols with the DEF property. First, we will demonstrate that there is no optimal on-line scalar DEF protocol, in terms of the number of forced checkpoints. Then some techniques for comparing protocols are proposed. We will construct some patterns or give formal proofs to compare the performance of both index-based and model-based protocols.