Transcript Introduction to Parallel Computing on the TeraGrid Part 1: the TeraGrid and Parallel Computing concepts Craig Stewart, [email protected] Associate Dean, Research Technologies & Chief Operating Officer,

Introduction to Parallel Computing on
the TeraGrid
Part 1: the TeraGrid and Parallel
Computing concepts
Craig Stewart, [email protected]
Associate Dean, Research Technologies &
Chief Operating Officer, Pervasive Technology Labs; IU
Chair, Coalition for Academic Scientific Computing
IU TeraGrid Resource Partner PI
&
Maytal Dahan, [email protected]
Software Developer, Distributed & Grid Computing, TACC
9 June 2008
License terms
•
•
Please cite as: Stewart, C.A., and M. Dahan. 2008. Introduction to Parallel
Computing on the TeraGrid. Part 1: the TeraGrid and Parallel Computing concepts.
Tutorial presentation. Presented at TeraGrid08 Conference, June 9-13, Las Vegas,
NV. http://hdl.handle.net/2022/13990
Some figures are shown here taken from web, under an interpretation of fair use
that seemed reasonable at the time and within reasonable readings of copyright
interpretations. Such diagrams are indicated here with a source url. In several
cases these web sites are no longer available, so the diagrams are included here
for historical value. Except where otherwise noted, by inclusion of a source url or
some other note, the contents of this presentation are © by the Trustees of Indiana
University. This content is released under the Creative Commons Attribution 3.0
Unported license (http://creativecommons.org/licenses/by/3.0/). This license
includes the following terms: You are free to share – to copy, distribute and transmit
the work and to remix – to adapt the work under the following conditions: attribution
– you must attribute the work in the manner specified by the author or licensor (but
not in any way that suggests that they endorse you or your use of the work). For
any reuse or distribution, you must make clear to others the license terms of this
work.
2
Outline
• Why this tutorial may be valuable to you
– (Time consuming computations on the critical path of your
research? Need more storage? Do you provide scientific
services/resources over the Web?)
• What is cyberinfrastructure?
• Examples of TeraGrid uses
• More detailed info about the TeraGrid
• How can you get going using the TeraGrid?
– Resources are available for use
– Help using the system is available
• Introduction to parallel computing concepts
• NB: ‘Tufte was here’
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What is cyberinfrastructure?
•
•
“Cyberinfrastructure consists of computing systems, data storage
systems, advanced instruments and data repositories, visualization
environments, and people, all linked together by software and high
performance networks to improve research productivity and enable
breakthroughs not otherwise possible.” (This and other information in
Wikipedia definition of cyberinfrastructure)
Some basic terms
– TFLOPS - Trillions of FLOating Point operations per Second
(mathematical operations) (10^12)
– Processor hour - one hour of processor (CPU) utilization
– TB - terabyte; PB - petabyte
– Parallel programming
– MPI - Message Passing Interface
– WSRF - Web Services Resource Framework
©Trustees of Indiana University. May be reused provided TeraGrid logo remains
and any modifications to original are noted. Courtesy Craig A. Stewart, IU
4
What is the TeraGrid?
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•
•
•
“TeraGrid is an open scientific discovery infrastructure combining leadership class
resources at eleven partner sites to create an integrated, persistent computational
resource.”
An instrument (cyberinfrastructure) that delivers high-end IT resources – storage,
computation, visualization, and data/service hosting – almost all of which are UNIX-based
under the covers; some hidden by web interfaces
– A data storage and management facility: over 20 petabytes of storage (disk and
tape), over 100 scientific data collections
– A computational facility: over 870 TFLOPS in parallel computing systems and
growing
– (Sometimes) an intuitive way to do very complex tasks, via Science Gateways, or get
data via data services
A service: help desk and consulting, Advanced Support for TeraGrid Applications (ASTA),
education and training events and resources
The largest individual cyberinfrastructure facility funded by the NSF, which supports the
national science and engineering research community
Something you can use without financial cost – allocated via peer review (and without
double jeopardy)
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Examples of what you can do with the TeraGrid:
Simulation of cell membrane processes
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Simulation of TonB-dependent transporter (TBDT)
Used 400,000 processor (CPU) hours on systems at
National Center for Supercomputing Applications,
IU, Pittsburgh Supercomputing Center [45 years
with one processor]
Modeled mechanisms for allowing transport of
molecules through cell membrane
Experimental analysis not possible!
Work by Emad Tajkhorshid and James Gumbart, of
University of Illinois Urbana-Champaign. Mechanics
of Force Propagation in TonB-Dependent Outer
Membrane Transport. Biophysical Journal 93:496504 (2007).
Results of the simulation may be seen at
www.life.uiuc.edu/emad/TonB-BtuB/btub2.5Ans.mpg
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Image courtesy of Emad Tajkhorshid, UIUC
Predicting storms
• Hurricanes and tornadoes cause massive
loss of life and damage to property
• TeraGrid supported spring 2007 NOAA
and University of Oklahoma Hazardous
Weather Testbed
– Major Goal: assess how well ensemble
forecasting predicts thunderstorms,
supercells  tornadoes
– Nightly reservation at PSC
– Delivers “better than real time”
prediction
– Used 675,000 CPU hours for the
season
– Used 312 TB on HPSS storage at PSC
– Used >100× more computing daily
than NWS operational forecasts
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Slide courtesy of Dennis Gannon, IU, and LEAD Collaboration
Solve any Rubik’s Cube in 26
moves?
• Rubik's Cube is perhaps the
most famous combinatorial
puzzle of its time
• > 43 quintillion states
(4.3x10^19)
• Gene Cooperman and Dan
Kunkle of Northeastern Univ.
proved any state can be
solved in 26 moves
• 7TB of distributed storage on
TeraGrid allowed them to
develop the proof
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Source: http://www.physorg.com/news99843195.html
NUs used
Molecular Biosciences
Chemistry
Astronomical Sciences
Physics
Materials Research
Chemical, Thermal Systems
Earth Sciences
All 18 Others
Advanced Scientific Computing
Atmospheric Sciences
0
50000000
100000000 150000000 200000000 250000000 300000000 350000000 400000000
• Resources for many disciplines
• Resource availability growing at unprecedented rates
• These data for first quarter of calendar 2008
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The TeraGrid Map
Grid Infrastructure
Group (UChicago)
UW
PSC
UC/ANL
NCAR
PU
NCSA
IU
Caltech
UNC/RENCI
ORNL
Tennessee
USC/ISI
SDSC
LONI/LSU
TACC
Resource Provider (RP)
Software Integration Partner
Network Hub
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www.teragrid.org
But the map doesn’t matter TeraGrid Architecture
RP 1
RP 2
POPS
(for now)
User
Portal
Science
Gateways
TeraGrid Infrastructure
Accounting, …
(Accounting, Network,Network,
Authorization,…)
Command
Line
RP 3
©University of Chicago, Courtesy Dane Skow, Director, TeraGrid Grid Infrastructure Group.
Used with Permission and modified substantially from original by Craig A. Stewart
Compute
Service
Viz
Service
Data
Service 11
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www.teragrid.org
TeraGrid High Performance Computing
Systems 2007-8
UC/ANL
NCAR
NCSA
PSC
PU
IU
ORNL
Tennessee
LONI/LSU
SDSC
TACC
NB: Ranger soon to be at 580 TFLOPS
Computational Resources
(size approximate - not to scale)
Slide Courtesy and © Tommy Minyard, TACC
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RANGER
• @ Texas Advanced Computing
Center’s Ranger
– Biggest open supercomputer in
world
– 504 TFLOPS Sun Constellation
Ranger – Sun Constellation Linux Cluster
(soon to be 580)
– 15,744 AMD Quad-core “Barcelona”
processors
– Disk subsystem - 1.7 petabytes
– First “Track II” system online
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Ranger info courtesy and © Tommy Minyard, TACC
NICS Systems
• Cray “Baker” system 2009
– ~1 PetaFLOPs
– Opteron multi-core
processors
– 100 TB of memory
– 2.3 PB of disk space
• Initial Delivery: July 2008
– 4,512 Opteron quad-core
processors
– 170 TeraFLOPs
© Oak Ridge National Labs
Quick summary of highlights of other
Resource Partner services later in
talk…
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Data storage and management: Disk
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All RP sites provide local working storage
Some RP sites provide storage as an allocatable resource
– GPFS-WAN (General Parallel File System Wide Area Network) ~ 1
petabyte
• Home at San Diego Supercomputer Center
• May be accessed as if it were a local file system from NCAR,
NCSA, IU, UC/ANL
– Lustre-WAN
• Production availability summer 2008 @ IU; direct mount to PSC
in testing now
• Several other RPs to experiment with Lustre-WAN this year
– Long term disk storage allocations
• IU, NCSA, SDSC
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Data storage and management: Tape
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Many RPs provide short term use of tape archives in support of
computation
TeraGrid provides persistent (up to Feb 2010+) storage on disk and
tape
Could you benefit from having a spare copy of your data stored
someplace removed from your home location?
Allocatable tape-based storage systems:
– IU (Indiana University) – geographically distributed
– NCAR (National Center for Atmospheric Research) – also supports
dual copy
– NCSA (National Center for Supercomputing Applications)
– SDSC (San Diego Supercomputer Center)
– Note: most sites have massive data storage systems that provide
storage in support of computation
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TGUP (TeraGrid User Portal)
motivation
• Aggregates and simplifies access to TG information &
services
• Control panel for active TG users with accounts
– Daily resource for TG users – check allocations, view
system information, submit consulting ticket, view
documentation etc.
• Make using TG simple, like a financial portal
• Increase productivity of TeraGrid researchers – do more
science!
TGUP (TeraGrid User Portal) vision
• The TeraGrid User Portal will continue to integrate important
user capabilities in one place:
– Comprehensive TeraGrid allocation and account
management
– TeraGrid user documentation, consulting, training info,
knowledge base
– Comprehensive RP resource information services
– Simple access to GIG and RP interactive grid usage –
logging in, remote viz, etc.
– Potentially, all user services and interactions (e.g., surveys,
online training, real-time consulting, interactive data mining,
remote visualization, etc.)
Accessing TeraGrid User Portal
• How do I access the TeraGrid
User Portal?
http://portal.teragrid.org
– When you get your accounts
packet you will have a portal
account (username and password)
listed
– The portal account is also your
TG-Wide login and can be used to
access any of your TG systems
– You can change your portal
password by logging in to the user
portal, visiting the MyTeraGrid tab,
and going to the ‘Change Portal
Password’ link
www.teragrid.org
Current Features
• Account Management Services
– Detailed projects and allocation usage
• Log in to the user portal to view your projects, allocations, usage, PI, Grant #
• PIs have expanded information including users that belong to their project
– View system accounts
• Complete list of system accounts with ability to log in directly to any TG system
– Seamless Login to TG systems
• No need to remember usernames or passwords
• SSH directly in to a TG system
– User Profile listing and update
• View & Update your user profile
– Change portal password
– Distinguished name listing tool
– Add/remove users
• PIs can request users be added/removed from an allocation
– Request community account
• Gateway projects can request a community account
Current Features
• Resource Services
– System Monitor
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View comprehensive list of TG resources
View detailed job information for each resource
View static resources attributes
Can sort by column
– Batch queue prediction service
• Wait time prediction
• Deadline prediction
– View & access TG science gateways
– View & access TG data collections
Current Features
• Interactive Services
– Interactive Remote Visualization
• To Maverick
– GSI-SSH login to TG systems
• SSH window to any TG system you have an account on
• No need to install any software, know your local account info, or
authenticate
– File Manager (coming soon)
Current Features
• Allocation Services
–
–
–
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Info about how to apply for allocations
Lists resources!
Sample proposals, proposal questions
Link to POPS Allocation request/renewal
• Training Services
– Calendar of training courses
– Comprehensive listing of online training modules
• Documentation Services
– Knowledge Base interface
•
View and search TG related documentation
– User Info documentation
•
Pulled from user information on TG web site
– Automatic population of user forms
•
Consulting form, feedback form, add/remove user form, etc.
• Consulting Services
– Help desk form, submit consulting tickets
File Manager Service
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Portal Interface for drag and drop file management across TeraGrid
Transfer between local machine <-> TG System, TG system <-> TG System
Set Notifications, View Xfer History
Secure, High Performance, No additional authentication required
Status: Friendly user testing phase
www.teragrid.org
Release: Early Summer 2008
Automated Password Reset
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Automatically reset
portal/TG-Wide password
via user portal
No need to contact help
desk or have original TG
paperwork
Status: Implementation
phase
Release: Summer 2008
www.teragrid.org
Planned Features
• Enhanced authentication/POPS integration
– Seamless POPS integration
• Automatic authentication to POPS for TeraGrid Users
– Vetted and un-vetted user portal accounts
• Replace POPS accounts with un-vetted user accounts
• When user gets an allocation the account becomes vetted
• User Documentation Services
– Software listing
• View CTSS and 3rd party software on TG systems
– User news integration
– Search feature – TGUP, website
• Customization and personalization
– Domain specific views
• Customized portal views for users based on scientific domains
– Personalize portal interface
• View only resources you are interested in, etc.
TeraGrid User Portal @ TG08
• Want to learn more about the TeraGrid User Portal?
– TeraGrid User Portal Birds of a Feather
• Tuesday, June 10th
• 5:30 – 6:30pm
– TeraGrid User Portal Paper Presentation
• "Increasing TeraGrid User Productivity through Integration of
Information and Interactive Services"
• Wednesday, June 11th
• 2:00 - 2:30pm
Science Gateways
• A Science Gateway is a domain-specific computing
environment, typically accessed via the Web, that provides a
scientific community with end-to-end support for a particular
scientific workflow
• Science Gateways are distinguished from web portals
(http://en.wikipedia.org/wiki/Web_portal) in that portals “present
information from diverse sources in a unified way.”
• Hides complexity (pay no attention to the grid behind the
curtain…)
©Trustees of Indiana University. May be reused provided TeraGrid logo
remains and any modifications to original are noted. Courtesy Craig A. Stewart,
IU
30
LEAD (portal.leadproject.org)
•
•
•
Simple enough an undergraduate can use it!
National Center for Supercomputing Applications (NCSA) and IU teamed up to
support WxChallenge weather forecast competition. 64 teams, 1000 students,
~16,000 CPU hours on Big Red
XBaya is available from http://www.collab-ogce.org/
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Purdue’s NanoHUB (www.nanohub.org)
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U. Chicago SIDGrid
(sidgrid.ci.uchicago.edu)
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IU Render Portal
Image by Chris Matusek
•
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Image by Ralf Frieser
Supports scientific visualization
Supports education in visualization, graphics, and new media
©Trustees of Indiana University. May be reused provided TeraGrid logo
remains and any modifications to original are noted. Courtesy Craig A. Stewart,
IU
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TeraGrid Science Gateways
Accessible at http://www.teragrid.org/programs/sci_gateways/
Title
Discipline
Open Science Grid (OSG)
Advanced Scientific Computing
Special PRiority and Urgent Computing Environment (SPRUCE)
Advanced Scientific Computing
Massive Pulsar Surveys using the Arecibo L-band Feed Array (ALFA)
Astronomical Sciences
National Virtual Observatory (NVO)
Astronomical Sciences
High Resolution Daily Temperature and Precipitation Data for the
Northeast United States
Atmospheric Sciences
Linked Environments for Atmospheric Discovery (LEAD)
Atmospheric Sciences
Computational Chemistry Grid (GridChem)
Chemistry
Computational Science and Engineering Online (CSE-Online)
Chemistry
Network for Earthquake Engineering Simulation (NEES)
Earthquake Hazard Mitigation
GEON(GEOsciences Network)
Earth Sciences
NanoHUB
Nanotechnology
TeraGrid Geographic Information Science Gateway (GISolve)
Geography
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TeraGrid Science Gateways
Accessible at http://www.teragrid.org/programs/sci_gateways/
Title
Discipline
CIG Science Gateway for the Geodynamics Community
Geophysics
QuakeSim (QuakeSim)
Geophysics
The Earth System Grid (ESG)
Global Atmospheric Research
National Biomedical Computation Resource (NBCR)
Integrative Biology and Neuroscience
Developing Social Informatics Data Grid (SIDGrid)
Language, Cognition, and Social
Behavior
Neutron Science TeraGrid Gateway (NSTG)
Materials Research
Biology and Biomedicine Science Gateway
Molecular Biosciences
Open Life Sciences Gateway (OLSG)
Molecular Biosciences
The Telescience Project
Neuroscience Biology
Grid Analysis Environment (GAE)
Physics
SCEC Earthworks Project
Seismology
TeraGrid Visualization Gateway
Visualization, Image Processing
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Hosting services
• Remember that old Waffle House commercial?
• If you have a data set or a data resource that serves
a national community (or even a community that
extends beyond your home institution… or a
community you would like to extend beyond your
home institution) …
• Hosting of your service is available via the TeraGrid
©Trustees of Indiana University. May be reused provided TeraGrid logo
remains and any modifications to original are noted. Courtesy Craig A. Stewart,
37
MutDB (www.mutdb.org)
http://www.chembiogrid.org/
©Trustees of Indiana University. May be reused provided TeraGrid logo
remains and any modifications to original are noted. Courtesy Craig A. Stewart,
IU
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Getting an account and allocation
• Get a POPS (Partnership Online Proposal System) account
• Apply for a DAC allocation (Development Allocation Committee):
< 5 TB disk, < 25 TB tape storage, and/or < 30,000 Standard
Units (SUs - related to CPU hours - in general an SU on one of
the newer TeraGrid systems is about 0.5 CPU hours)
• Wait a month (although any RP can help you shorten that!)
• Read the introductory documentation
• Use the TeraGrid KB if you need
• Ask for help ([email protected])
• Go discover!
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Go to the POPS page https://pops-submit.teragrid.org/
ç
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Create a POPS Login
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www.teragrid.org
Indicate that you are “New” to the Teragrid
ç
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www.teragrid.org
Indicate that this is a “Start-up” Request
ç
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www.teragrid.org
Select DAC-TG (nonintuitive)
ç
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www.teragrid.org
Fill out PI information
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www.teragrid.org
Skip Co-PIs probably (unless Co-PI has
current funding and you don’t)
ç
ç
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www.teragrid.org
Fill out info on your project
ç
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www.teragrid.org
Fill out info on your funding
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www.teragrid.org
Make reasonable estimates about your computing
ç
ç
ç
ç
ç
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www.teragrid.org
Upload your CV and Submit!
ç
çwhen ready
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www.teragrid.org
Highlights of facilities at several RPs
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Texas Advanced Computing Center
EnVision – Web-based Remote Visualization
Ranger – Sun Constellation Linux Cluster
TeraGrid Funded
http://envision.tacc.utexas.edu
580TF, 3,936 AMD Blades (62,976 cores), 123 TB Memory, 1.73 PB
Storage, InfiniBand Interconnect
First Track2 deployment!
Ranch – Storage Facility
Lonestar – Dell Linux Cluster
Sun E25K
128 SPARC4 Cores
500 GB Memory
16 Frame Buffers
Sun STK SL8500 Tape
System
5 PB Capacity, 20 TB Disk
Cache
Maverick – Remote Visualization
System
62TF, 1,460 PowerEdge Blades (5,840 cores), 10.4 TB
Memory, 105 TB Parallel File System, InfiniBand
Interconnect
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© TACC
Pittsburgh Supercomputing Center
www.psc.edu © PSC
• The Pittsburgh Supercomputing Center, established 1986, is a joint
effort of Carnegie Mellon University and the University of Pittsburgh
together with Westinghouse Electric Company.
• PSC is a Resource Provider in the NSF TeraGrid program, providing
capability-class and high-productivity resources and extensive
computational science support to researchers nationwide.
• PSC contributes to the TeraGrid’s coordinating Grid Infrastructure
Group (GIG) with leadership roles in user support, security,
accounting, education, outreach, and training.
• Wide-ranging contributions to high-performance computing,
communications, storage, outreach, and science, such as:
• Advanced networking: Web100, National LamdaRail, 3ROXSM, …
• National Resource for Biomedical Supercomputing (NIH)
• SuperComputing Science Consortium ( (SC)2; DOE/Regional )
• Zest high-performance snapshot service
BigBen
Cray XT3; 4132c,
21.5Tf, 4TB
Pople
Salk
Rachel, Jonas
SGI Altix 4700;
SGI Altix 4700; HP GS1280; each
1.5TB shared, 768c 288GB, 144c
512GB, 128p
Golem
SGI Altix
450
High-resolution CFD simulation of
collateral blood flow in the Circle of
Willis, performed at PSC and TACC
by Leopold Grinberg (Brown Univ.)
and visualized by Greg Foss (PSC).
Scratch
Storage
Storage
Cache Nodes
Storage
Silos
200 TB
100 TB
2 PB
NCAR TeraGrid Overview – TG’08
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TeraGrid Resources at NCAR
– Computing Resources
• 5.7 TFLOPS, 2048 processor IBM Blue
Gene/L with 1 TB of memory
• 20 TB of attached disk storage
– Data and Visualization Resources
• 150 TB Online SAN Disk
– Visualization Resources
• Sun Ultra 40
Focus Areas
– Domain specific computing for the
atmospheric and related sciences
– Large dataset visualization
• http://www.vapor.ucar.edu
– Science Gateways
• Earth System Grid
• Asteroseismology Gateway
– Urgent/On-demand Compute Access
– Lustre and GPFS-wan testing and
deployment
– EOT Internship and visitor programs:
• http://www.cisl.ucar.edu/siparcs
• http://www.cisl.ucar.edu/rsvp
© NCAR
SDSC TeraGrid Overview – TG’08
• Resources
– Compute
• DataStar – IBM Power4+
• BlueGene Data – IBM Blue Gene
• TeraGrid Cluster – Intel IA-64
– Data
• 2.5 PB Online SAN Disk
• 25 PB Archive
• 100+ Data Collections
• Focus Areas
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–
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Advanced Support for TeraGrid Applications (ASTA)
Co/Meta-Scheduling and Advanced Reservations
On-demand Compute Access
Global File Systems
Dual-site Archival Storage
Education, Outreach, and Training
Indiana University
• IU foci:
– Science Gateways and
gateway hosting (Quarry)
– Lustre-WAN (production this
summer) (Data Capacitor)
– Data collection hosting,
massive data storage
– Big Red – WRF, Molecular
dynamics
NCSA Abe
• The NCSA Intel 64 Linux Cluster Abe is intended to provide a
capability resource for computationally challenging problems
• Production jobs should typically use at least 1000 cores
• Requests for extended access for large scale runs is encouraged
• Specs
– Linux cluster
– 89.47 TFLOPS
– 9600 CPUs
• http://www.ncsa.uiuc.edu/UserInfo/Resources/Hardware/Intel64Clust
er/
TeraGrid RP Resource Highlights
© Purdue University
Steele – A cluster with 812 dual
quad-core nodes, each with 1632GB memory. GigE/InfiniBand.
~60TFlops.
Condor – Over 14000 CPUs with a total of over 60
TFlops. Linux, Windows. Condor is designed for highthroughput computing, and is excellent for parameter sweeps,
Monte Carlo simulation, or most any serial application, and
some classes of parallel jobs such as master-worker
applications.
Brutus - SGI 450 with 4
Storage – 200 TB BlueArc Titan storage for user home
FPGAs for development of
FPGA accelerated applications directories and scratch space; 1.3 PB tape archival storage.
and services. Condor
TeraDRE – High-throughput visualization resource built
schedulable.
on Condor Pools. A 48-node subcluster featuring Nvidia
GeForce 6600 GT GPUs. Supports Maya, POV-Ray, Blender
and Gelato. http://www.purdue.edu.teragrid/teradre.
Data Collections – SRB managed
datasets (incl. real-time satellite images,
NEXRAD radar streams, remote sensing data)
and application services (OpenDAP,
THREDDS)..
6/5/2008
A conceptual introduction to parallel
programming
• How many people can effectively build a house?
– Two people perhaps in half the time it takes one, perhaps
less than that
– Four in ~ half the time of two
– If you had 1,024 people…
– And what if one worker is not very effective?
• And some things you simply cannot do in parallel
60
Some key definitions and ideas
• Parallel computing is a form of computation in which many
instructions are carried out simultaneously, operating on the
principle that large problems can often be divided into smaller
ones, which are then solved concurrently ("in parallel”)
[Wikipedia]
• Nicely parallel (sometimes called ‘trivially parallel’)
• High Throughput Computing (4 color theorem, folding at home,
particle physics)
• High Performance Computing, Supercomputing
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Amdahl’s Law
P = parallel fraction of program
N = number of processors
Formula and graph from wikipedia.org
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Gustafson’s Law and types of scaling
S(P) = P – α(P-1)
• A driving metaphor (from Wikipedia)
– Suppose a car is traveling between two cities 60 miles apart, and
has already spent one hour traveling half the distance at 30 mph.
• Amdahl's Law approximately suggests: “No matter how fast you drive
the last half, it is impossible to achieve 90 mph average before
reaching the second city. Since it has already taken you 1 hour and
you only have a distance of 60 miles total; going infinitely fast you
would only achieve 60 mph.”
– Gustafson's Law approximately states: “Given enough time and
distance to travel, the car's average speed can always eventually
reach 90mph, no matter how long or how slowly it has already
traveled. For example, in the two-cities case this could be achieved
by driving at 150 mph for an additional hour.”
63
Gustafson’s Law and types of scaling
S(P) = P – α(P-1)
• Strong scaling: measure time to solution with fixed problem
size, vary the number of processors
• Weak scaling: measure time to solution with problem size
growing as processor count (fixed system size per processor).
• In the end scientific progress is a function of hardware,
software, insight, and patience
64
65
Shared vs Distributed Memory
66
Problems today and tomorrow
(continuing in part with house
analogy)
• What if getting the 2x4s to where they go were a bigger problem
than nailing them in place?
• What if part of the time you wanted to give the wood you’re
working on over to a Mitre saw and then have it handed back to
you?
• Multicore – not MPI on a chip (Tom Sterling)
• Speed of light – not changing anytime soon
• Real time response
67
Additional info
• Getting started guide - includes examples of good
proposals:
http://www.teragrid.org/userinfo/getting_started.php
• Review criteria:
http://www.teragrid.org/userinfo/access/allocationspol
icy.php
• When you’re in a foreign country there is nothing like
a guide. If you need help with the application process
submit a help request via the TeraGrid
([email protected])
68
Acknowledgements
•
IU’s involvement as a TeraGrid Resource Partner is supported in part by the National Science Foundation
under Grants No. ACI-0338618l, OCI-0451237, OCI-0535258, and OCI-0504075. The IU Data Capacitor is
supported in part by the National Science Foundation under Grant No. CNS-0521433. IU research
presented here is supported in part by the Pervasive Technology Labs and the Indiana METACyt Initiative;
both of these IU initiatives are supported by the Lilly Endowment, Inc., as well as Shared University
Research grants from IBM, Inc. to IU. The LEAD portal is developed under the leadership of IU Professors
Dr. Dennis Gannon and Dr. Beth Plale, and supported by NSF grant 331480. Marcus Christie and Surresh
Marru of the Extreme! Computing Lab contributed the LEAD graphics. The ChemBioGrid Portal is
developed under the leadership of IU Professor Dr. Geoffrey C. Fox and Dr. Marlon Pierce and funded via
the Pervasive Technology Labs (supported by the Lilly Endowment, Inc.) and the National Institutes of
Health grant P20 HG003894-01. Many of the ideas presented in this talk were developed under a Fulbright
Senior Scholar’s award to Stewart, funded by the US Department of State and the Technische Universitaet
Dresden.
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The Grid Infrastructure Group is funded by NSF grant 0503697.
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Purdue’s involvement as a TeraGrid Resource Partner is supported in part by the National Science
Foundation under Grant No. OCI-050399.
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Any opinions, findings and conclusions or recommendations expressed in this material are those of the
authors and do not necessarily reflect the views of the National Science Foundation (NSF), National
Institutes of Health (NIH), Lilly Endowment, Inc., or any other funding agency.
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This work is made possible by many staff throughout the US who are striving to make the TeraGrid a critical
asset for the US in scientific discovery and global competitiveness.
Thank you! Any questions?
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