PQPCkpt: An efficient three level synchronous checkpointing scheme in mobile computing systems

Distributed domino effect-free checkpointing techniques can be divided into two categories: coordinated and communication-induced checkpointing. The f ormer is inappropriate for mobile computing systems because it either force s every mobile host to take a new checkpoint or blocks the underlying compu tation during the checkpointing process. The latter makes every mobile host take the checkpoint independently. However, each mobile host may need to s tore multiple local checkpoints in stable storage. This investigation prese nts a novel three level synchronous checkpointing algorithm that combines t he advantages of above two methods for mobile computing systems. The algori thm utilizes pre-synchronization, quasi-synchronization, and post-synchroni zation techniques and has the following merits: (1) Consistent global check points can be ensured. (2) No mobile host is blocked during checkpointing. (3) Only twice the checkpoint size is required. (4) Power consumption is lo w. (5) The disconnection problem of mobile hosts can be resolved. (6) Very few mobile hosts in doze mode are disturbed. (7) It is simple and easy to i mplement. The proposed algorithm's numerical results are also provided in t his work for comparison. The comparison reveals that our algorithm outperfo rms other algorithms in terms of checkpoint overhead, maintained checkpoint s, power consumption, and disturbed mobile hosts.