1. Support for Global Cloud Resolving Model Simulations VACET All-Hands Meeting IEEE Vis 2008

2. Support for Global Cloud Resolving Model Simulations VACET All-Hands Meeting IEEE Vis 2008 PRABHAT

3.  SciDAC/INCITE  PI: Dave Randall (CSU)  2008 INCITE award at NERSC  Multi-institution collaboration  CSU researchers developing the climate simulation  PNNL researchers developing the Data API  VACET researchers helping w/ Data model, Parallel IO and Vis

4.  Global atmospheric circulation model  non-hydrostatic dynamical core  cloud microphysics, turbulence, radiation  coupled to land-surface model  3km grid-cell spacing  Planned runs on 20K+ franklin cores  Planned 1:1 simulated:wall_clock time  Data throughput  ~1TB/hr  2GB/s aggregate IO performance requirement  ~500M cells*100 layers, 50 variables

5.  Identify a data model for GCRM code  Enable simulation code to do efficient parallel IO  Visualization and Analysis on extremely large icosahedral meshes

6.  1 st Phase: NetCDF-3  metadata conventions  Icosahedral mesh variables/layout ▪ cell/corner/edge/face centered ▪ satisfy VisIt plugin requirements  2 nd Phase NetCDF-4 (HDF5)

7.  Need sustained 2+GB/s collective IO to single shared file  Current franklin performance ~0.3-1.2 GB/s (for single file)  Large number of IOR tests examining factors  IO patterns  lustre striping  blocking/transfer sizes  #IO nodes, #OSTs

8.  Issues identified with Cray's mpich implementation  Not sufficiently aware of OST striping  Modifying HDF5 to align/pad to OST stripes  Current best strategy is to use  2-phase IO (use aggregator nodes)  #IO nodes = #OSTs  Match file transfer size to stripe width  Simulate ‘file-per-process’ IO pattern

9.  VisIt plugin developed to load icosahedral NetCDF mesh data  Preliminary custom visualizations rendered  Online tutorials and startup instructions published at: http://vis.lbl.gov/~prabhat/Incite19/

11.  Further work w/ Cray on optimizing mpi-io  Finalize data model  cell/corner/edge/face centered data  validate NetCDF-4  VisIt plugin enhancements  parallelization  incorporate morton-ordering

12.  Colorado State Univ  Dave Randall, Ross Heikes  PNNL  Karen Schuchardt, Bruce Palmer, Annette Koonz  LBNL  Janet Jacobsen, Wes Bethel  Mark Howison  Katie Antypas, John Shalf, Shane Canon  VisIt team

13. VisIt Update (Hank’s part)  Project is doing very well  There is an upcoming slide on partnering  Much more like an open source project  SVN repo at LBL through SciDAC Outreach Center  Mailing lists at ORNL  ~200 people on users lists  Visitusers.org Wiki  Wiki for developers and users  Tutorials (at SciDAC conf, Snowbird, PPPL)

14. Likely upcoming features in the next year  SciDAC stuff:  Poincare plots  Integration of FastBit  VisTrails (?)  Non-SciDAC stuff:  Qt4  Parallel Python  Hopefully more for in-situ, multi-res, and time- varying data.  + a lot more…

15. ASC / LLNL Eric Brugger (PL) Kathleen Bonnell Hank Childs Cyrus Harrison Mark Miller Brad Whitlock SciDAC/LBL Gunther Weber Prabhat SciDAC/LLNL Hank Childs Brad Whitlock SciDAC/ORNL Sean Ahern Jeremy Meredith David Pugmire SciDAC/UCDavis Christoph Garth Oliver Ruebel Eduard Dienes SciDAC/UUtah Josh Stratton GNEP/LLNL David Bremer Hank Childs AWE Matt Wheeler Paul Selby CEA Fabien Vivodtzev ORNL Institutional Sean Ahern Jamison Daniel Jeremy Meredith David Pugmire LBL Institutional Gunther Weber Prabhat INL Institutional Jim Galbraith ANL Institutional Randy Hudson LDRD/LLNL Daniel Laney Hank Childs Oil $ to LLNL Eric Brugger UCDavis: Research John Anderson UNH: Research Tom Fogal ITT (Industry) Matt Fago + more partnerships coming soon (NSF?) + contributions from people not in the repository