Adaptive Checkpointing for Master-Worker Style Parallelism

We present a transparent, system-level checkpointing solution for master-worker parallelism that automatically adapts, upon restore, to the number of processor nodes available. We call this adaptive checkpointing. This is important, since nodes in a cluster fail. It also allows one to adapt to using mutliple cluster partitions, as they become available. Checkpointing a master-worker computation has the additional advantage of needing to checkpoint only the master process. This is both fast (0.05 s in our case), and more economical of disk space. We describe a system-level solution. The application writer does not declare what data structures to checkpoint. Furthermore, the solution is transparent. The application writer need not add code to request a checkpoint at appropriate locations. The system-level strategy avoids the labor-intensive and error-prone work of explicitly checkpointing the many data structures of a large program