Handling Recurrent Failures in Coordinated Checkpointing for Mobile Distributed Systems

We propose a minimum-process coordinated checkpointing algorithm for non-deterministic mobile distributed systems, where no useless checkpoints are taken. An effort has been made to minimize the blocking of processes and synchronization message overhead. We capture the partial transitive dependencies during the normal execution by piggybacking dependency vectors onto computation messages. Frequent aborts of checkpointing procedure may happen in mobile systems due to exhausted battery, non-voluntary disconnections of MHs, or poor wireless connectivity. Therefore, we propose that in the first phase, all concerned MHs will take mutable checkpoint only. Ad hoc checkpoint is stored on the memory of MH only. In this case, if some process fails to take checkpoint in the first phase, then MHs need to abort their ad hoc checkpoints only. In this way, we try to minimize the loss of checkpointing effort when any process fails to take its checkpoint in coordination with others.