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Grids: A Reality Check
Mark Hayes
GEFD Summer School 2003
It’s not just compute cycles...
An exponential growth in data from many areas of science.
4 types of Grid
• CPU intensive cycle scavenging (SETI@home)
• Data sharing
• Application provision
• Human-human interaction (e.g. Access Grid)
SETI@home
The world’s most powerful computer
delivered 52 Teraflops/second yesterday
(Earth Simulator is 35 Tflop/s, sum of top 2-10 is 60Tflop/s)
Latest Stats
http://setiathome.ssl.berkeley.edu/totals.html
6th July 2003
Total
Last 24 Hours
Users
4,570,474
1,226
Results received
944 M
1.1 M
Total CPU time
1.5 M years
1,226 years
Floating Point
Operations
3 E+21 ops
3 zeta ops
4.5 E+18 flops/day
52 Teraflops/s
The data explosion - some big numbers
• CFD turbulence simulations - 100TB
• BaBar particle physics experiment - 1TB/day
• CERN LHC will generate 1GB/s or 10PB/year
• VLBA radio telescope generates 1GB/s today
• NCBI/EMBL database is “only 0.5TB” but doubling each year
• brain imaging - 4TB/brain at full colour, 10mm resolution
(4PB/brain at 1mm i.e. cellular resolution)
• Pixar - 100TB/movie
FTP and GREP are not adequate (Jim Gray)
Application provision
• Google - 10K cpus, 2PB database (2 years ago)
• free email services - HotMail, Yahoo! 2-10PB storage
• netsolve - numerical algorithms on demand
with Matlab & Mathematica plugins
• renderfarm.net - graphics rendering on demand
The Access Grid
High end video conferencing
and collaboration technology.
O(100) nodes world wide.
Presenter
mic
Presenter
camera
Ambient mic
(tabletop)
Audience camera
“...one of the most compelling glimpses into the future I’ve seen since I first saw NCSA Mosaic.”
Larry Smarr
£1 buys...
•
•
•
•
•
•
•
1 day of cpu time
4 GB ram for a day
1 GB of network bandwidth
1 GB of disk storage
10 M database accesses
10 TB of disk access (sequential)
10 TB of LAN bandwidth (bulk)
How do you move a terabyte?
Source: Terascale SneaketNet, Jim Gray et al
Context
Speed
Mbps
Rent
$/month
$/Mbps
$/TB
Sent
Time/TB
Home phone
0.04
40
1,000
3,086
6 years
Home DSL
0.6
70
117
360
5 months
T1
1.5
1,200
800
2,469
2 months
T3
43
28,000
651
2,010
2 days
OC3
155
49,000
316
976
14 hours
OC 192
9600
1,920,000
200
617
14 minutes
100 Mpbs
100
1 day
Gbps
1000
2.2 hours
Some consequences
Compute cycles are (almost) free...
by comparison with network costs.
-The cheapest and fastest way to move 1TB of
data out from CERN is still by FedEx.
Though this considers only bandwidth,
low latency networks are even more expensive!
(MPI over WAN doesn’t work well.)
What makes a good Grid application?
A distributed community of users.
Tiny network input & output, huge compute
requirement.
Database access & storage is also expensive,
therefore put the computation near the data.
The Grid in the UK
Pilot projects in particle physics,
astronomy, medicine, bioinformatics,
environmental sciences...
Contributing to international
Grid software development efforts
10 regional “eScience Centres”
The European DataGrid
• Tiered structure: Tier0=CERN
• Lots of their own Grid software
•Applications: particle physics,
earth observation, bioinformatics
http://www.eu-datagrid.org/
NASA Information PowerGrid
• First “production quality” Grid
• Linking NASA & academic
supercomputing sites at 10 sites
• Applications: computational fluid
dynamics, meteorological data
mining, Grid benchmarking
http://www.ipg.nasa.gov/
TeraGrid
• Linking supercomputers
through a high-speed network
• 4x 10GBps between SDSC,
Caltech, Argonne & NCSA
• Call for proposals out for
applications & users
http://www.teragrid.org/
Asia-Pacific Grid
• No central source of funding
• Informal, bottom-up approach
• Lots of experiments on
benchmarking & bio apps.
http://www.apgrid.org/
What does it take to build a Grid?
• Resources - CPU, network, storage
• People - sysadmins, application developers, Grid experts
• Grid Middleware - Globus, Condor, Unicore…
• Security - so you want to use my computer?
• Maintenance - ongoing monitoring, upgrades… and
co-ordination of this between multiple sites
• Applications and users!
How you can get involved...
• NIEeS - http://www.niees.ac.uk/
• National eScience Centre (Edinburgh)
http://www.nesc.ac.uk/
•Your local eScience Centre
• Adopt an application!
Questions?