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SCEC/CME Project - How Earthquake Simulations Drive Middleware Requirements

SCEC/CME Project - How Earthquake Simulations Drive Middleware Requirements. Philip Maechling SCEC IT Architect 24 June 2005. Southern California Earthquake Center. Consortium of 15 core institutions and 39 other participating organizations, founded as an NSF STC in 1991

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SCEC/CME Project - How Earthquake Simulations Drive Middleware Requirements

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  1. SCEC/CME Project - How Earthquake Simulations Drive Middleware Requirements Philip Maechling SCEC IT Architect 24 June 2005

  2. Southern California Earthquake Center • Consortium of 15 core institutions and 39 other participating organizations, founded as an NSF STC in 1991 • Co-funded by NSF and USGS under the National Earthquake Hazards Reduction Program (NEHRP) • Mission: • Gather data on earthquakes in Southern California • Integrate information into a comprehensive, physics-based understanding of earthquake phenomena • Communicate understanding to end-users and the general public to increase earthquake awareness and reduce earthquake risk Core Institutions University of Southern California (lead) California Institute of Technology Columbia University Harvard University Massachusetts Institute of Technology San Diego State University Stanford University U.S. Geological Survey (3 offices) University of California, Los Angeles University of California, San Diego University of California, Santa Barbara University of Nevada, Reno Participating Institutions 39 national and international universities and research organizations http://www.scec.org GRIDS Center Community Workshop 2005

  3. Recent Earthquakes In California GRIDS Center Community Workshop 2005

  4. Observed Areas of Strong Ground Motion GRIDS Center Community Workshop 2005

  5. Simulations Supplement Observed Data GRIDS Center Community Workshop 2005

  6. SCEC/CME Project Goal:To develop a cyberinfrastructure that can support system-level earthquake science – the SCEC Community Modeling Environment (CME) Support:5-yr project funded by the NSF/ITR program under the CISE and Geoscience Directorates Start date: Oct 1, 2001 NSF CISE GEO SCEC/ITR Project ISI USGS Information Science Earth Science SDSC IRIS SCEC Institutions www.scec.org/cme GRIDS Center Community Workshop 2005

  7. SCEC/CME Scientific Workflow Construction A major SCEC/CME objective is the ability to construct and run complex scientific workflow for SHA Lat/Long/Amp (xyz file) with 3000 datapoints (100Kb) Define Scenario Earthquake ERF Definition Calculate Hazard Curves Extract IMR Value Plot Hazard Map 9000 Hazard Curve files (9000 x 0.5 Mb = 4.5Gb) IMR Definition GMT Map Configuration Parameters Gridded Region Definition Probability of Exceedence and IMR Definition Pathway 1 example GRIDS Center Community Workshop 2005

  8. SCEC/CME Scientific Workflow System GRIDS Center Community Workshop 2005

  9. Select Receiver (Lat/Lon) Output Time History Seismograms Select Scenario Fault Model Source Model SCEC Community Library SCEC/CME SRB-based Digital Library SRB-based Digital Library • More than 100 Terabytes of tape archive • 4 Terabytes of on-line disk • 5 Terabytes of disk cache for derivations GRIDS Center Community Workshop 2005

  10. INTEGRATED WORKFLOW ARCHITECTURE J. Zechar @ USC (Teamwork: Geo + CS) Workflow Template Editor (CAT) Query for components D. Okaya @ USC Tools Domain Ontology Workflow Template (WT) Workflow Library Component Library Query for WT Data Selection L. Hearn @ UBC Query for data given metadata COMPONENTS I/O data descriptions Conceptual Data Query Engine (DataFinder) Metadata Catalog Workflow Instance (WI) Execution requirements Engineer Workflow Mapping (Pegasus) Grid information services Tools Grid K. Olsen @ SDSU Executable Workflow GRIDS Center Community Workshop 2005

  11. SCEC/CME HPC Allocations • SCEC/CME researchers have need and have access to significant High Performance Computing capabilities • TeraGrid Allocations (April 2005 – March 2006) • TG-MCA03S012 (Olsen) 1,020,000 SUs • TG-BCS050002S (Okaya) 145,000 Sus • USC HPCC Allocations • CME Group Allocations (Maechling) 100,000 SUs • Investigator Allocations (Li, Jordan) 300,000 SUs • SCEC Cluster • Dedicated Pentium 4 16 Processor Cluster (102 GFlops) GRIDS Center Community Workshop 2005

  12. SCEC/CME TeraGrid Support • TeraGrid Strategic Application Collaboration (SAC) greatly improved our AWM run-time on TeraGrid • Advanced TeraGrid Support (ATS) for TeraShake 2 and CyberShake simulations • SDSC Visualization Services support for SCEC simulations. GRIDS Center Community Workshop 2005

  13. Three Types of Simulations • SCEC/CME supports widely varying types of earthquake simulations • Each Simulation type creates it’s own set of middleware requirements • Will Describe three examples and comment on their middleware implications and on computational system requirements: • Probabilistic Seismic Hazard Maps • 3D Waveform Propagation Simulations • 3D Waveform-based Intensity Measure Relationship GRIDS Center Community Workshop 2005

  14. Earthquake-Rupture Forecast (ERF) • Probability of all possible • fault-rupture events (M≥~5) • for region & time span Intensity-Measure Relationship (IMR) Gives Prob(IMT≥IML) for a given site and fault-rupture event Full-Waveform Modeling (developmental) (more physics) Attenuation Relationships (traditional) (no physics) Probabilistic Seismic Hazard Maps

  15. Example Hazard Curve Site: USC ERF: Frankel-02 IMR: Field IMT: Peak Velocity Time Period: 50 Years GRIDS Center Community Workshop 2005

  16. Probabilistic Hazard Map Calculations GRIDS Center Community Workshop 2005

  17. Characteristic of PSHA Simulations • 10k Independent hazard curve calculations for each map calculations. • High throughput, not high performance, computing problem. • 10k resulting files per map • Metadata saved for each file • Short run times on each calculation • Overhead of starting up job is expensive. • Would like to offer map calculations as service to SCEC users (who may not have an allocation) GRIDS Center Community Workshop 2005

  18. Middleware Implications • High throughput scheduling • Well Suited to Condor Pool • Bundling of short run-time jobs will reduce job startup overhead. • Bundling of jobs useful for clusters execution. • Metadata tracking with a RDBMS-based catalog system (e.g. Metadata Catalog System (MCS) and Replication Location Service (RLS) • Databases present installation and operational problems at ever site we request them • Software support for interpreted language on Computational Clusters • Implemented in an interpreted programming language • On-demand execution by non-allocated user GRIDS Center Community Workshop 2005

  19. 3D Wave Propagation Simulations GRIDS Center Community Workshop 2005

  20. Characteristics of 3D Wave Propagation Simulations • More physically realistic than existing PSHA but more computationally expensive. • High Performance Computing, cluster-based codes • 4D data calculations (time varying volumetric data) • Output large volumetric data sets • Physics limited by resolution of grid. Higher ground motion frequencies require denser grid. Double of density increases storage by factor of 8. GRIDS Center Community Workshop 2005

  21. Example: TeraShake Simulation • Magnitude 7.7 earthquake on southern San Andreas • Mesh of ~2 billion cubes, dx=200 m • 0.011 sec time step, 20,000 time steps: 3 minute simulation • Kinematic source (from Denali) from Cajon Creek to Bombay Beach • 60 sec source duration • 18,886 point sources, each 6,800 time steps in duration • 240 processors at San Diego SuperComputer Center DataStar • ~ 20,000 CPU hours, approximately 5 days wall clock • ~ 50 Tbytes of output • During execution “on-the-fly” graphics (…attempt aborted!) • Metadata capture and storage in the SCEC digital library GRIDS Center Community Workshop 2005

  22. Domain Decomposition For TeraShake Simulations GRIDS Center Community Workshop 2005

  23. Simulations Supplement Observed Data GRIDS Center Community Workshop 2005

  24. Peak Velocity NW-SE Rupture SE-NW rupture GRIDS Center Community Workshop 2005

  25. Montebello: 337 cm/s Downtown: 52 cm/s Long Beach: 48 cm/s San Diego: 8 cm/s Palm Springs: 36 cm/s SE-NW Montebello: 8 cm/s Downtown: 4 cm/s Long Beach: 9 cm/s San Diego: 6 cm/s Palm Springs: 23 cm/s NW-SE SCEC/CME

  26. Break-down of output GRIDS Center Community Workshop 2005

  27. Middleware Implications for 3D Wave Propagation Simulations • Multi-day high performance runs • Check point restart support needed • Schedule reservations on clusters • Reservations and special queues are often arranged. • Large file and data movement • TeraByte transfers require high reliably, long term, data transfers • Ability to stop and restart • Can we move restart from one system to another • Draining of temporary storage during runs • Storage required for full often exceeds capability of scratch, so output files must be moved during simulation GRIDS Center Community Workshop 2005

  28. Middleware Implications for 3D Wave Propagation Simulations • On the fly visualization for rapid validation of results • Verify before full simulation is completed • Standard protocols for data transfers, and metadata registration into SRB-based storage GRIDS Center Community Workshop 2005

  29. Earthquake-Rupture Forecast (ERF) • Probability of all possible • fault-rupture events (M≥~5) • for region & time span Intensity-Measure Relationship (IMR) Gives Prob(IMT≥IML) for a given site and fault-rupture event Full-Waveform Modeling (developmental) (more physics) Attenuation Relationships (traditional) (no physics) Waveform-based Intensity Measure Relationship (CyberShake)

  30. Various IMR types (subclasses) Attenuation Relationships Gaussian dist. is assumed; mean and std. from various parameters IMT, IML(s) Multi-Site IMRs compute joint prob. of exceeding IML(s) at multiple sites (e.g., Wesson & Perkins, 2002) Rupture Site(s) Intensity-Measure Relationship List of Supported IMTs List of Site-Related Ind. Params Vector IMRs compute joint prob. of exceeding multiple IMTs (Bazzurro & Cornell, 2002) Simulation IMRs exceed. prob. computed using a suite of synthetic seismograms

  31. CyberShake Simulations Push Macro and Micro Computing • CyberShake requires large forward wave propagation simulations, volumetric data storage • CyberShake requires 100k seismogram synthesis computations using multi-Terabyte volumetric data sets. During synthesis processing, this data needs to be disk-based. • 100k of data files, and metadata, files to be managed • High throughput requirements are driving implementation toward TeraGrid wide computing approach. • High throughput requirements are driving integration of non-TeraGrid grids with TeraGrid GRIDS Center Community Workshop 2005

  32. Example CyberShake Region (200km x 200km) USC: 34.05,-118.24 minLat=31.889, minLon=-120.60, maxLat=36.1858, maxLon=-115.70 GRIDS Center Community Workshop 2005

  33. CyberShake Strain Green Tensor AWM • Large (TeraShake Scale) forward calculations for each site. • SHA typically ignore rupture > 200km from site, so this is used as cutoff distance. • 20km buffer distance is used around edges of volume to reduce edge effects • 65km depth to support frequencies of interest • Volume is 440km x 440km x 65km at 200m spacing • 1.573 Billion mesh pts • Simulation time 240 seconds • Volumetric Data Saved for 2 horizontal simulations • Estimated Storage per site is: 7 TB (4.5 data 2.5 checkpoint files) GRIDS Center Community Workshop 2005

  34. Ruptures in ERF within 200KM of USC 43227 Ruptures in Frankel02 ERF with M 5.0 or larger within 200km of USC GRIDS Center Community Workshop 2005

  35. CyberShake Computational Elements GRIDS Center Community Workshop 2005

  36. CyberShake Seismogram Synthesis • Requires calculation of 100,000+ seismogram for each site. • Estimate Rupture Variations scale by magnitude: • Mw 5.0 x 1 = 20,450 • Mw 6.0 x 10 = 216,990 • Mw 7.0 x 100 = 106,900 • Mw 8.0 x 1000 = 9,000 ------------------ 353,340 Ruptures x 2 components • Current estimated number of seismogram files per site is 43,000 (due to combining components and variations into single file per rupture). GRIDS Center Community Workshop 2005

  37. CyberShake Seismogram Synthesis • Seismogram synthesis stage requires disk-based data storage of large volumetric data sets so tape based archive of volumetric data sets does not work. • To distribute seismogram synthesis across TeraGrid, we need to either duplicate TB of data, or have global visibility on disks systems GRIDS Center Community Workshop 2005

  38. Example Hazard Curve Site: USC ERF: Frankel-02 IMR: Field IMT: Peak Velocity Time Period: 50 Years GRIDS Center Community Workshop 2005

  39. Workflows run Using Grid VDS Workflow Tools GRIDS Center Community Workshop 2005

  40. Examples Hazard Map Region (50km x 50km at 2km grid spacing = 625 sites) OpenSHA SA 1.0 Frankel 2002 ERF and Sadigh with 10% POE in 50 years. GRIDS Center Community Workshop 2005

  41. Summary of SCEC Experiences • As soon as we develop a computational capability, the geophysicists develop application that push the technology. • Compute technology, data management technology, resource sharing technology all are applied. • In many ways, IT capabilities required for geophysical problems exceed what is currently possible and limit the state of knowledge in geophysics and public safety. • For example, higher frequency simulations, are of significant interest, but exceed computational and storage capabilities currently available. GRIDS Center Community Workshop 2005

  42. Major Middleware related issues for SCEC/CMESecurity and Allocation Management • No widely accepted CA makes adding organizations to SCEC grid problematic. • Ability to run under group allocations for “on demand” requests. (Community Allocation ?) GRIDS Center Community Workshop 2005

  43. Major Middleware related issues for SCEC/CMESoftware Installation and Maintenance • Middleware software stack, even at supercomputer systems, support should include micro jobs support such as Java. • Database management support for database-oriented tools such as Metadata Catalogs are important (backup, recovery, cleanup, performance, modifications) • Guidelines for tools in middleware software stack, should describe when local installations are required and when remote installations are acceptable for tools such as RLS and MCS GRIDS Center Community Workshop 2005

  44. Major Middleware related issues for SCEC/CMESupercomputing and Storage • Globally (TeraGrid – wide) visible disk storage • Well supported, reliable file transfers with monitoring and restart of jobs with problems are essential. • Interoperability between grid tools and data management tools such as SRB must include data and metadata and metadata search. GRIDS Center Community Workshop 2005

  45. Major Middleware related issues for SCEC/CMEScheduling Issues • Support for Reservation-based scheduling • Partial run and restart capability • Failure detection and alerting GRIDS Center Community Workshop 2005

  46. Major Middleware related issues for SCEC/CMEUsability Related and Monitoring • Monitoring tools that include status of available storage resources. • On-the-fly visualizations for run-time validation of results • Interfaces to workflow systems are complex, developer oriented interfaces. Easier to user interfaces needed GRIDS Center Community Workshop 2005

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