VSC Training Course: Introduction to Hybrid Programming in HPC, June 17-18, 2020


    Most HPC systems are clusters of shared memory nodes. To use such systems efficiently both memory consumption and communication time has to be optimized. Therefore, hybrid programming may combine the distributed memory parallelization on the node interconnect (e.g., with MPI) with the shared memory parallelization inside of each node (e.g., with OpenMP or MPI-3.0 shared memory). This course analyzes the strengths and weaknesses of several parallel programming models on clusters of SMP nodes. Multi-socket-multi-core systems in highly parallel environments are given special consideration. MPI-3.0 has introduced a new shared memory programming interface, which can be combined with inter-node MPI communication. It can be used for direct neighbor accesses similar to OpenMP or for direct halo copies, and enables new hybrid programming models. These models are compared with various hybrid MPI+OpenMP approaches and pure MPI. Numerous case studies and micro-benchmarks demonstrate the performance-related aspects of hybrid programming.

    Hands-on sessions are included on both days. Tools for hybrid programming such as thread/process placement support and performance analysis are presented in a "how-to" section. This course provides scientific training in Computational Science, and in addition, the scientific exchange of the participants among themselves.

    This course is organized in cooperation with the High-Performance Computing-Center Stuttgart (HLRS) and the Erlangen Regional Computing Center (RRZE).

    Agenda & Content (preliminary):

    1st day:

    08:45   Registration
    09:00      Welcome
    09:05      Motivation
    09:15      Introduction
    09:45      Programming Models
    09:50       - MPI + OpenMP
    10:30   Coffee Break
    10:50       - continue: MPI + OpenMP
    11:40         Practical (how to compile and start)
    12:30   Lunch
    13:30         Practical (hybrid through OpenMP parallelization)
    15:00   Coffee Break
    15:20       - Overlapping Communication and Computation
    15:40         Practical (taskloops)
    16:20       - MPI + OpenMP Conclusions
    16:30       - MPI + Accelerators
    16:45      Tools
    17:00   End of first day

    2nd day:

    09:00      Programming Models (continued)
    09:05       - MPI + MPI-3.0 Shared Memory
    09:45         Practical (replicated data)
    10:30   Coffee break
    10:50         continue: Practical (replicated data)
    11:50       - MPI Memory Models and Synchronization
    12:30   Lunch
    13:30       - Pure MPI
    13:50       - Topology Optimization
    14:30   Coffee Break
    14:50         Practical (application aware Cartesian topology)
    15:45       - Topology Optimization (Wrap up)
    16:00      Conclusions
    16:15      Q & A
    16:30   End of second day (course)


    Basic MPI and OpenMP knowledge as presented, e.g., in our VSC Training Courses on MPI and OpenMP.
    For the hands-on sessions you should know Unix/Linux and either C/C++ or Fortran in particular.


    Georg Hager (RRZE / HPC, Uni. Erlangen), Rolf Rabenseifner (HLRS, Uni. Stuttgart),
    Claudia Blaas-Schenner and Irene Reichl (VSC Team, TU Wien)



    Date, Time, and Location:

    17.06.2020 8:45 - 18.06.2020 16:30,
    FH Internet-Raum FH1 (TU Wien, Wiedner Hauptstraße 8-10, ground floor, red area)


    Opens external link in new windowRegistration form

    Registration will start on April 15, 2020.

    Registration deadline is Tuesday, May 19, 2020, with priority rules. Acceptance will be approved on May 20, 2020. As long as seats are available there will be an extended registration period without priority rules.

    Priority for acceptance: first - active users of the VSC systems, second - students and members of Austrian universities and public research institutes, third - other applicants.


    VSC users: none
    Students and members of Austrian universities and public research institutes: none
    Students and members of other universities and public research institutes: 120 €
    Others: 400 €

    Information about payment will be provided with the confirmation email.

    The course fee includes the coffee breaks (lunch is not included).


    Course material (slides & exercises):

    All course material will be made available here at course start.


    Local Organizer / Contact:

    Claudia Blaas-Schenner, vsc-seminar@list.tuwien.ac.at


    Training events (further courses) at:

    VSC: Opens external link in new windowvsc.ac.at/training

    HLRS: Opens external link in new windowwww.hlrs.de/training