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Climate Research at the National Energy Research Scientific Computing Center (NERSC) Bill Kramer Deputy Director and Head of High Performance Computing CAS 2001 October 30, 2001. #. NERSC Vision.
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Climate Research at the National Energy Research Scientific Computing Center (NERSC) Bill Kramer Deputy Director and Head of High Performance Computing CAS 2001 October 30, 2001 #
NERSC Vision NERSC strives to be a world leader in accelerating scientific discovery through computation. Our vision is to provide high-performance computing tools and expertise to tackle science's biggest and most challenging problems, and to play a major role in advancing large-scale computational science and computer science.
Outline • NERSC-3: Successfully fielding the world’s most powerful unclassified computing resource • The NERSC Strategic Proposal: An Aggressive Vision for the Future of the Flagship Computing Facility of the Office of Science • Scientific Discovery through Advanced Computing (SciDAC) at NERSC • Support for Climate Computing at NERSC: Ensuring Success for the National Program
FY00 MPP Users/Usage by Scientific Discipline NERSC FY00 MPP Users by Discipline NERSC FY00 MPP Usage by Discipline
NERSC FY00 Usage by Site MPP Usage PVP Usage
NERSC Computing Highlights for FY 01 • NERSC 3 is in full and final production – exceeding original capability by more than 30% and with much larger memory. • Increased total FY 02 allocations of computer time by 450% over FY01. • Activated the new Oakland Scientific Facility • Upgraded NERSC network connection to 655 Mbits/s (OC12) – ~4 times the previous bandwidth. • Increase archive storage capacity with 33% more tape slots and double the number of tape drives • PDSF, T3E, SV1s, and other systems all continue operating very well
Oakland Scientific Facility • 20,000 sf computer room; 7,000 sf office space • 16,000 sf computer space built out • NERSC occupying 12,000 sf • Ten-year lease with 3 five-year options • $10.5M computer room construction costs • Option for additional 20,000+ sf computer room
HPSS Archive Storage • 190 Terabytes of data in the storage systems • 9 Million files in the storage systems • Average 600-800 GBs Data transferred/day • Peak 1.5 TB • Average 18,000 files transferred/day • Peak 60,000 • 500-600 Tape mounts/day • Peak 2000) (12/system)
NERSC-3 Vital Statistics • 5 Teraflop/s Peak Performance – 3.05 Teraflop/s with Linpack • 208 nodes, 16 CPUs per node at 1.5 Gflop/s per CPU • “Worst case” Sustained System Performance measure .358 Tflop/s (7.2%) • “Best Case” Gordon Bell submission 2.46 on 134 nodes (77%) • 4.5 TB of main memory • 140 nodes with 16 GB each, 64 nodes with 32 GBs, and 4 nodes with 64 GBs. • 40 TB total disk space • 20 TB formatted shared, global, parallel, file space; 15 TB local disk for system usage • Unique 512 way Double/Single switch configuration
Two Gordon Bell-Prize Finalists Are Using NERSC-3 • Climate Modeling -- Shallow Water Climate Model sustained 361 Gflop/s (12%) – S. Thomas et al., NCAR. • Materials Science -- 2016-atom supercell models for spin dynamics simulations of magnetic structure of iron-magnanese/cobalt interface. Using 2176 processors of NERSC 3 showed a sustained 2.46 teraflop/s – M. Stocks and team at ORNL and U. Pittsburgh with A. Canning at NERSC Section of an FeMn/Co interface shows a new magnetic structure that is different from the magnetic structure of pure FeMn.
HPSS HPSS SGI HIPPI ESnet NERSC System Architecture FDDI/ ETHERNET 10/100/Gigbit REMOTE VISUALIZATION SERVER MAX STRAT SYMBOLIC MANIPULATION SERVER IBM And STK Robots DPSS PDSF ResearchCluster CRI T3E 900 644/256 CRI SV1 MILLENNIUM LBNL Cluster IBM SP NERSC-3 – Phase 2 2532 Processors/ 1824 Gigabyte Memory/32 Terabytes of Disk VIS LAB
NERSC Strategic Proposal An Aggressive Vision for the Future of the Flagship Computing Facility of the Office of Science
The NERSC Strategic Proposal • Requested In February, 2001 by the Office of Science as a proposal for the next five years of the NERSC Center and Program • Proposal and Implementation Plan delivered to OASCR at the end of May, 2001 • Proposal plays from NERSC’s strengths, but anticipates rapid and broad changes in scientific computing. • Results of DOE review expected at the end of November-December 2001
High-End Systems: A Carefully Researched Plan for Growth A three-year procurement cycle for leading-edge computing platforms Balanced Systems, with appropriate data storage and networking
NERSC Support for the DOE Scientific Discovery through Advanced Computing (SciDAC)
Scientific Discovery Through Advanced Computing Materials Combustion DOE Science Programs Need Dramatic Advances in Simulation Capabilities To Meet Their Mission Goals Global Systems Health Effects, Bioremediation Subsurface Transport Fusion Energy
Applied Partial Differential Equations ISIC Developing a new algorithmic and software framework for solving partial differential equations in core mission areas. • New algorithmic capabilities with high-performance implementations on high-end computers: • Adaptive mesh refinement • Cartesian grid embedded boundary methods for complex geometries • Fast adaptive particle methods • Close collaboration with applications scientists • Common mathematical and software framework for multiple applications Participants: LBNL (J. Bell, P. Colella), LLNL , Courant Institute, Univ. of Washington, Univ. of North Carolina, Univ. of California, Davis, Univ. of Wisconsin.
Scientific Data Management ISIC • Goals • Optimize and simplify: • Access to very large data sets • Access to distributed data • Access of heterogeneous data • Data mining of very large data sets Petabytes Tapes Scientific Simulations & Experiments Terabytes Disks SDM-ISIC Technology Data Manipulation: Data Manipulation: • Optimizing shared access from mass storage systems • Metadata and knowledge- based federations • API for Grid I/O • High-dimensional cluster analysis • High-dimensional indexing • Adaptive file caching • Agents ~20% time • Using SDM-ISIC technology • Getting files from tape archive • Extracting subset of data from files • Reformatting data • Getting data from heterogeneous, distributed systems • Moving data over the network ~80% time Scientific Analysis & Discovery ~80% time Participants: ANL, LBNL, LLNL, ORNL, GTech, NCSU, NWU, SDSC Scientific Analysis & Discovery ~20% time
Strategic Project Support • Specialized Consulting Support • Project Facilitator Assigned • Help defining project requirements • Help with getting resources • Code tuning and optimization • Special Service Coordination • Queues, throughput, increased limits, etc. • Specialized Algorithmic Support • Project Facilitator Assigned • Develop and improve algorithms • Performance enhancement • Coordination with ISICs to represent work and activities
Strategic Project Support • Special Software Support • Projects can request support for packages and software that are special to their work and not as applicable to the general community • Visualization Support • Apply NERSC Visualization S/W to projects • Develop and improve methods specific to the projects • Support any project visitors who use the local LBNL visualization lab • SciDAC Conference and Workshop Support • NERSC Staff will provide content and presentations at project events • Provide custom training as project events • NERSC staff attend and participate at project events
Strategic Project Support • Web Services for interested projects • Provide areas on NERSC web servers for interested projects • Password protected areas as well • Safe “sandbox” area for dynamic script development • Provide web infrastructure • Templates, structure, tools, forms, dynamic data scripts (cgi-gin) • Archive for mailing lists • Provide consulting support to help projects organize and manage web content • CVS Support • Provide a server area for interested projects • Backup, administration, access control • Provide access to code repositories • Help projects set up and manage code repositories
NERSC Support for Climate Research Ensuring Success for the National Program
Climate Projects at NERSC • 20+ projects from the base MPP allocations with about ~6% of the entire base resource • Two Strategic Climate Projects • High Resolution Global Coupled Ocean/Sea Ice Modeling – Matt Maltrud @ LANL • 5% of total SP hours (920,000 wall clock hours) • “Couple high resolution ocean general circulation model with high resolution dynamic thermodynamic sea ice model in a global context.” • 1/10th degree (3 to 5 km in polar regions) • Warren Washington, Tom Bettge, Tony Craig, et al. • PCM coupler
Early Scientific Results Using NERSC-3 • Climate Modeling – 50km resolution for global climate simulation run in a 3 year test. Proved that the model is robust to a large increase in spatial resolution. Highest spatial resolution ever used, 32 times more grid cells than ~300km grids, takes 200 times as long. – P. Duffy, LLNL Reaching Regional Climate Resolution
Some other Climate Projects NERSC staff have helped with • Richard Loft, Stephen Thomas and John Dennis, NCAR - Using 2,048 processors on NERSC-3, demonstration that dynamical core of an atmospheric general circulation model (GCM) can be integrated at a rate of 130 years per day • Inez Fung (UCB) - CSM to build a Carbon Climate simulation package using the SV1 • Mike Wehner - CCM to do large scale ensemble simulations on T3E • Doug Rotman – Atmospheric Chemistry/Aerosol Simulations • Tim Barnett and Detlaf Stammer – PCM runs on T3E and SP.
ACPI/Avantgarde/SciDAC • Work done by Chris Ding and team • comprehensive performance analysis of GPFS on IBM SP (supported by Avant Garde). • I/O performance analysis, see http://www.nersc.gov/research/SCG/acpi/IO/ • numerical reproducibility and stability • MPH: a library for distributed multi-component environment
Special Support for Climate Computing NCAR CSM version 1.2 • NERSC was the first site to port NCAR CSM to non-NCAR Cray PVP machine • Main users Inez Fung (UCB) and Mike Wehner (LLNL) NCAR CCM3.6.6 • Independent of CSM, NERSC ported NCAR CCM3.6.6 to NERSC Cray PVP cluster. • See http://hpcf.nersc.gov/software/apps/climate/ccm3/
Special Support for Climate Computing – cont. • T3E netCDF parallelization • NERSC solicited user input for defining parallel I/O requirements for the MOM3, LAN and CAMILLE climate models (Ron Pacanowski, Venkatramani Balaji, Michael Wehner, Doug Rotman and John Tannahill) • Development of netCDF parallelization on T3E was done by Dr. RK Owen at NERSC/USG based on modelers requirements • better I/O performance, • master/slave read/write capability • support for variable unlimited dimension • allow subset of PEs open/close netCDF dataset • user friendly API • etc. • Demonstrated netCDF parallel I/O usage by building model specific I/O test cases (MOM3, CAMILLE). • netCDF 3.5 official UNIDATA release includes “added support provided by NERSC for multiprocessing on Cray T3E.“ http://www.unidata.ucar.edu/packages/netcdf/release-notes-3.5.0.html • Parallel netCDF for IBM SP under development by Dr. Majdi Baddourah of NERSC/USG
Additional Support for Climate • Scientific Computing and User Service’s Groups have staff with special climatic focus • Received funding for a new climate support person at NERSC • Will provide software, consulting, and documentation support for climate researchers at NERSC • Will port the second generation of NCAR's Community Climate System Model (CCSM-2) to NERSC's IBM SP. • Put the modified source code under CVS control so that individual investigators at NERSC can access the NERSC version, and modify and manipulate their own source without affecting others. • Provide necessary support and consultation on operational issues. • Will develop enhancements to NetCDF on NERSC machines that benefit NERSC's climate researchers. • Will respond in a timely, complete, and courteous manner to NERSC user clients, and provide an interface between NERSC users and staff.
NERSC Systems Utilization IBM SP – 80-85% Gross utilization T3E – 95% Gross utilization
NERSC Systems Run “large” Jobs IBM SP T3E
Balancing Utilization and Turnaround • NERSC consistently delivers high utilization on MPP systems, while running large applications. • We are now working with our users to establish methods to provide improved services • Guaranteed throughput for at least a selected group of projects • More interactive and debugging resources for parallel applications • Longer application runs • More options in resource requests • Because of the special turnaround requirements of the large climate users • NERSC established a queue working group (T. Bettge, Vince Wayland at NCAR) • Set up special queue scheduling procedures that provide an agreed upon amount of turnaround per day if there is work in it (Sept. ‘01) • Will present a plan at the NERSC User Group Meeting, November 12, 2001 in Denver, about job scheduling
Wait times in “regular” queue Climate jobs All other jobs
NERSC Is Delivering on Its Commitment to Make the Entire DOE Scientific Computing Enterprise Successful • NERSC sets the standard for effective supercomputing resources • NERSC is a major player in SciDAC and will coordinate it projects and collaborations • NERSC is providing targeted support to SciDAC projects • NERSC continues to provide targeted support for the climate community and is acting on the input and needs of the climate community