For the past few years, OpenACC has been the primary directive-based API for programming accelerator devices like GPUs. OpenMP 4.0 is now a competitor in this space, with support from different vendors. In this paper, we describe an algorithm to convert (a subset of) OpenACC to OpenMP 4; we implemented this algorithm in a prototype tool and evaluated it by translating the EPCC Level 1 OpenACC benchmarks. We discuss some of the challenges in the conversion process and propose what parts of the process should be automated, what should be done manually by the programmer, and what future research and development is necessary in this area.
The Open OnDemand Project is an open-source software project, based on the proven OSC OnDemand platform, to allow HPC centers to install and deploy advanced web and graphical interfaces for their users. The Open OnDemand team is completing the first year of the project and releasing its first version this summer. In this paper, we describe the user experience and design of Open OnDemand and discuss next steps for the open source project.
Batch environments are notoriously unfriendly because it's not easy to interactively diagnose the health of a job. A job may be terminated without warning when it reaches the end of an allotted runtime slot, or it may terminate even sooner due to an unsuspected bug that occurs only at large scale. Two strategies are proposed that take advantage of DMTCP for system-level checkpointing. First, we describe how to easily implement extended batch sessions that overcome the typical limitation of 24 hours maximum for a single batch job on large HPC resources. This removes the necessity for the application-specificcheckpointing found in many long-running codes. Second, we describe a three-phase debugging strategy that permits one to interactively debug long-running MPI applications that were developed for non-interactive batch environments.
