Checkpoint and recovery (CPR) systems have many uses in high-performance computing. Because of this, many developers have implemented it, by hand, into their applications. One of the uses of checkpointing is to help mitigate the effects of interruptions in computational service (both planned and unplanned) In fact, some supercomputing centers expect their users to use checkpointing as a matter of policy. And yet, few centers provide fully automatic checkpointing systems for their high-end production machines. The paper is a status report on our work on the family of C3systems for (almost) fully automatic checkpointing for scientific applications. To date, we have shown that our techniques can be used for checkpointing sequential, MPI and OpenMP applications written in C, Fortran, and several other languages. A novel aspect of our work is that we have not built a single checkpointing system, rather, we have developed a methodology and a set of techniques that have enabled us to develop a number of systems, each meeting different design goals and efficiency requirements

Utility computing is becoming a popular way of exploiting the potential of computational grids. In utility computing, users are provided with computational power in a transparent manner similar to the way in which electrical utilities supply power to their customers. To take full advantage of utility computing, an application needs to be mobile; that is, it needs to be able to migrate between heterogeneous computing platforms while it is executing. Further, it needs to be able to adapt to the computing resources at each site, such as the number of available physical processors. At present, there are few high-performance computing applications of this sort, and re-engineering legacy codes to be mobile can take enormous effort.In this paper, we describe theph$PC^3$ system, which converts C/MPI codes into mobile programs almost transparently. Because it is based on portable application-level checkpointing, it enables the state of running applications to be saved so that the application can be restarted on different architectures, operating systems and MPI implementations. Moreover, the number of processors on these machines can be different. To our knowledge, this is the first system to provide all these features. Experimental results show that the overhead introduced by the system is usually small.

The running times of many computational science applications are much longer than the mean-time-to-failure of current high-performance computing platforms. To run to completion, such applications must tolerate hardware failures. Checkpoint-and-restart (CPR) is the most commonly used scheme for accomplishing this - the state of the computation is saved periodically on stable storage, and when a hardware failure is detected, the computation is restarted from the most recently saved state. Most automatic CPR schemes in the literature can be classified as system-level checkpointing schemes because they take core-dump style snapshots of the computational state when all the processes are blocked at global barriers in the program. Unfortunately, a system that implements this style of checkpointing is tied to a particular platform; in addition, it cannot be used if there are no global barriers in the program. We are exploring an alternative called application-level, non-blocking checkpointing. In our approach, programs are transformed by a pre-processor so that they become self-checkpointing and self-restartable on any platform; there is also no assumption about the existence of global barriers in the code. In this paper, we describe our implementation of application-level, non-blocking checkpointing. We present experimental results on both a Windows cluster and a Compaq Alpha cluster, which show that the overheads introduced by our approach are small.