Visualization and Data Analysis using VisIt - In Situ Visualization -

Transcription

1 Mitglied der Helmholtz-Gemeinschaft Visualization and Data Analysis using VisIt - In Situ Visualization - Jens Henrik Göbbert 1, Herwig Zilken 1 1 Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, Germany Application Support, Cross-Sectional-Team Visualization {j.goebbert, h.zilken}@fz-juelich.de Folie 1

2 Motivation why not stick to the established workflow Application CIAO on JUQUEEN (specific setup) Excellent scaling of solver File writing dumping output is bottleneck at scale dump simulation data with high temporal resolution not possible Folie 2

3 In Situ Visualization visualization for large-scale simulations post visualization Visualization of simulation data in a post processing step requires to write and then read files, paying for I/O twice in different application. in situ visualization visualization capabilities inside the simulation avoid I/O compression method Folie 3

4 Motivation lowering the barriers to in-situ visualization Major barriers to in situ visualization are first, the individual implementation-, optimization- and coupling-costs to integrate the needed functionality to each simulation code and setup can often not be justified. second, the usage of in situ visualization requires much training for scientists who's research work in general does not focus on visualization in the first place. Lowering the barriers to in-situ visualization Folie 4

5 Applications coupled with VisIt/Libsim psopen flow solver (DNS) highly resolved turbulence pseudo-spectral approach Institute for Combustion Technology RWTH Aachen University, Germany Chair of Num. Thermo-Fluid Dyn. TU Freiberg, Germany Fortran90 + MPI + OpenMP JUQUEEN BigWeek participant CIAO flow solver (LES, DNS) multiphysics, multiscale structured finite difference method level-set for surface tracking level-set/volume-of-fluid interface Lagrange particle solver tabulated/finite rate chemistry overset mesh refinement moving meshes Institute for Combustion Technology RWTH Aachen University, Germany Fortran90 + MPI JUQUEEN BigWeek participant ZFS flow solver (LES, DNS) multiphysics, multiscale finite volume method lattice-boltzmann method discontinuous Galerkin method level-set for surface tracking Lagrangian particle solver Institute of Aerodynamics Aachen RWTH Aachen University, Germany C MPI + OpenMP + GPU Folie 5

6 Staged In Situ small compute node big compute node GPU HPC file system interactive visualization node GPU HPC interconnect small compute nodes für die Simulation big compute nodes für die nachgelagerte Verarbeitung Visualisierung/Analyse der Rohdaten unmittelbares Rendering auf big nodes mit OpenGL-fähigen GPUs Pro: Contra: exklusive Hardwareresourcen für Simulation und nachgelagerte Verarbeitung Kopieren der Daten zwingend notwendig Folie 6

7 On-Node In-Situ small compute node HPC file system interactive visualization node HPC interconnect GPU small compute nodes Simulation und Visualisierung/Analyse der Rohdaten Pro: Contra: Kopieren von Daten zwischen Simulation und Datenverarbeitung entfällt keine exklusiven Hardwareresourcen für Simulation und Verarbeitung Folie 7

8 Coupling of Simulation and Visualization/Analysis no coupling Simulation Visualization tightly-coupling Simulation Visualization loosly-coupling Simulation In-Situ Framework Visualization 8 Folie 8

9 Tightly-Coupled In-Situ Visualization 9 Folie 9

10 network connection MPI Scalable Rendering Mode VisIt parallelized client-server architecture Local Components Parallel Cluster VisIt Engine Data Plugin Data VisIt Engine Data Plugin Data VisIt Viewer VisIt Engine Data Flow Network Data Plugin Data (Files or Simulation) Filter VisIt GUI VisIt CLI Python Clients Java Clients Filter Filter Folie 10

11 JUSITU coupling simulation code to in-situ visualization simulation VisIt/ Libsim ParaView/ Catalyst sim. developer vis. developer one data adapter for each visualization tool need for reinventing infrastructure code for each simulation to couple responsibility for coupling code by sim. developer changes on the visualization software side only possible in close cooperation with sim. developers Folie 11

12 JUSITU coupling simulation code to in-situ visualization simulation JUSITU VisIt/ Libsim ParaView/ Catalyst sim. developer vis. developer light-weighted, flexible and easy-to-use coupling library covers the complexity and numerous options of in-situ visualization simplifies communication between sim. developer and vis. developer written in C++ / MPI Folie 12

13 In Situ Visualization with VisIt/Libsim Folie 13