Workplan for the first year

The current support for the execution of parallel and MPI jobs is quite different in the existing EMI job management services.

In the ARC CE the middleware is just responsible to allocate the needed resources, and then the execution of the parallel job is fully managed by specific RunTime Environments (RTEs) which are set up at sites and advertised in the information system.

Something similar applies to the gLite job management services: once the resources needed for the execution of a parallel job have been allocated by the Computing Element, MPI-Start provides a unified layer for starting the parallel application, hiding the underlying details of the resources and MPI frameworks to the upper middleware layers and to the users.

UNICORE offers its users a easy-to-use and completely transparent way of submitting jobs to MPI and and other types of parallel environments such as OpenMP through so called “execution environments”. The site administrator describes the existing parallel environments in a configuration file. This file is used by UNICORE in two ways: on the one hand, to advertise the parallel environments to the clients. On the other hand, it prescribes how UNICORE should setup and start the parallel job. The UNICORE client software thus offers convenient ways to create parallel jobs, without requiring the user to know any site specifics.

Some harmonization in this area is definitely needed. The description for parallel and MPI jobs (along with the description of the needed resources) will be standardized in the context of the job related standardization activities. The standardization of the “back-end”, that is the provision of a standard EMI unified layer, targeted to the end user and responsible to manage the parallel application hiding the underlying details, will be assessed during the first project year.

Implementation

• Sept. 09, 2010: There will a session at EGI-TF in Amsterdam on parallel jobs. People from ARC, gLite and UNICORE will attend. This should be the chance to start discussing about some possible harmonizations in the area. Enol will circulate the outcomes of such discussions. Next steps will then be decided

MPI support and user experience in the various middlewares

At the Amsterdam F2F it was decided to give concrete examples for MPI job submission in the three middlewares. The idea was to aim for a consistent end user experience.

• ARC:
  • Hello World job
  • GROMACS-MPI RTE installation and usage examples
• gLite MPI-Start : http://devel.ifca.es/mpi-start/wiki/EMIUseCases
• UNICORE: MPIExamples EMI-ES Parallel Environment implementation