Grid Computing Introduction

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Grid Computing Introduction

• Sathish Vadhiyar

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Generic Grid Architecture/Components
Problem Solving Environments
Application Science Portals
Grid Access Info
User Portals
Scheduling Co- Scheduling
Service Layers
Naming Files
Fault Tolerance
Events
Authentication
Computers
Data bases
Online instruments
Software
Resource Layer
High speed networks and routers
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OK, I have built some software.Is mine a Grid
software?

• Ian Fosters three-point checklist
• coordinates resources not subject to centralized
  control
• using standard, open, general-purpose protocols
  and interfaces
• to deliver non-trivial qualities of service

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Some Myriad Definitions

• Coordinated resource sharing and problem solving
  in dynamic, multi-institutional virtual
  organizations
• Anatomy of the grid highly flexible sharing
  relationships, sophisticated and precise levels
  of control over use of shared resources, sharing
  of varied resources, diverse usage modes.
• Controlled sharing not free access
• Infrastructure enabling integrated,
  collaborative use of resources
• Sharing resources can vary dynamically vary over
  time
• More colorful definitions keep coming
• Common keywords Coordinated, shared,
  multi-institutions, controlled, usage,
  collaboration

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Differences with Other Technologies

• Enterprise-level distributed computing limited
  cross-organizational support
• Current distributed computing approaches do not
  provide a general resource-sharing framework that
  addresses Virtual Organization (VO) requirements.
• WWW just client-server. Lacks richer
  interaction models
• Technologies like CORBA, Java, DCOM single
  organization, limited scope
• Some of the Grid techniques complement existing
  techniques.

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Grids vs Conventional Distributed Computing
(Nemeth and Sunderam)

• Distributed Computing
• Virtual Pool of nodes
• Set of nodes static. Users have login access.
  They explicitly know about nodes
• VM constructed out of a priori knowledge
• Resource assignment implicit
• Resource owning
• Grid Computing
• Virtual Pool of wide range of resources
• Set of nodes static/dynamic. Resources dynamic
  and diverse can vary in number, can vary in
  performance
• Difficult for user to get a priori knowledge
• User abstraction at resource layers
• Resource sharing
• Apps. resource requirements more than can be
  solved on machines owned

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Continued
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Nemeth and Sunderam
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Motivating examples
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SETI_at_home

• To search new life and civilizations
• Use individual computers idle time through
  running SETI_at_home screen saver
• Screen savers retrieves data, analyzes and
  reports results back to SETI project
• Looking for extra-terrestrial signal over a
  12-second period
• Each work unit takes 10 to 50 hours on an average
  computer 2.4 to 3.8 trillion floating point
  operations

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Steps and Statistics
Data collected from Arecibo telescope in Puerto
Rico onto tapes and shipped to SETI_at_home lab in
UC, Berkeley. Break tapes -gt work units -gt given
to users
Find candidate signals reported from users

• Other steps
• Checking data integrity
• Removing radio frequency interference (RFI)
• Identify final candidates

Statistics 208,174,383 work units 1,261 tapes
Images and statistics from SETI web site
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Climateprediction.net

• Forecast climate in 21st century
• 3 steps explore current model, validate against
  past climate, forecast 21st century climate
• Different models (in terms of initial conditions,
  forcing volcanoes, solar activity etc.,
  parameters approximations or ranges of fixed
  values in the model. E.g. ice size in ocean,
  friction between different ocean layers)
  distributed to different users
• Massive ensemble experiment

From climateprediction.net
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Steps
From climateprediction.net
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Prime number generation - GIMPS

• Finding Mersenne prime numbers 2P-1
• GIMPS is to find largest known Mersenne prime
  numbers
• 41st Mersenne prime found recently -
  224,036,583-1 with 7,235,733 decimal digits !!!
• GIMPS found seven
• For mostly fun
• 1000s of Pentium PCs involved. Setup similar to
  SETI_at_home
• PCs do primality tests

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Other _at_home Projects

• genome_at_home designing new genes that form
  working proteins in cells. To study protein
  evolution. Individual PCs design protein
  sequences
• folding_at_home to study why proteins
  fold/misfold. Each PC simulates a particular kind
  of protein folding
• evolution_at_home to understand and simulate
  evolution
• Compute-against-cancer to study cancer cells
  and to design new cancer drugs
• FightAids_at_home screen millions of candidate
  drug compounds
• Distributed.net cryptography, secret key
  challenges
• More can be found in http//boinc.berkeley.edu/pro
  jects.php

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The Telescience project

• Grid for remote accessing microscopes, data
  analysis and visualization
• To study complex interactions of molecular and
  cellular biological structures and hence
  understand brain diseases
• Interactively steer a 400,000-volt electron
  microscope at UC San Diego

From TeleScience web site
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References

• http//www.globus.org/research/papers/chapter2.pdf
  
• What is the Grid? A three point checklist. Ian
  Foster. GRIDToday, July 20, 2002.
• The Anatomy of the Grid Enabling scalable
  virtual organizations. I. Foster, C. Kesselman,
  S. Tuecke. IJSA. 15(3), 2001.
• A Complete History of the Grid. Dr. Rob Baxter.
  Pdf
• Zsolt Nemeth, Mauro Migliardi, Dawid Kurzyniec
  and Vaidy Sunderam. A comparative analysis of
  PVM/MPI and computational grids. In EuroPVM/MPI
  2002.
• Zsolt Nemeth and Vaidy Sunderam. A comparison of
  conventional distributed computing environments
  and computational grids. ICCS 2002.
• Zsolt Nemeth and Vaidy Sunderam. A formal
  framework for defining grid systems. CCGrid 2002.