We present a checkpointing mechanism for a DSM system that, in spite of being invisible to the programmer, is quite efficient and portable. It is efficient because it is nonblocking, coordinated and thus domino-effect free. It offers some portability because it is built on top of MPI and uses only the services offered by MPI and a POSIX compliant local file system. As far as we know, this is the first real implementation of such a scheme for DSM. Along with the description of the algorithms used, we present experimental results obtained in a cluster of workstations, and discuss many insights that came out of the implementation effort. We hope that our research shows that efficient, transparent and portable checkpointing is viable for DSM systems.

This paper presents a checkpointing scheme that was implemented in a parallel library that runs on top of CHIMP/MPI. The main goals of the checkpointing mechanism are portability and efficiency. It runs on every platform supported by MPI in a machine-independent way. The scheme allows the migration of checkpoints and offers a flexible recovery mechanism based on data-reconfiguration. Some performance results will be presented at the end of the paper together with some techniques that can be used to increase the efficiency of the checkpointing mechanism.