The Grid from a User

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The Grid from a Users Perspective The Cluster
Finder Use Case

• Art Carlson
• AstroGrid-D, Heidelberg, 24 July 2006

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The bottom line

• The main thing I want the grid for is improving
  my top speed.
• I know I have to parallelize my code myself, but
  I want some support doing it.
• I dont want to have to port my code to more than
  one environment.

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Why galaxy clusters?
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Dark Matter Plasma Galaxies
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Cluster Finder Workflow
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Likelihood maps
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No shortage of data or questions

• More sky 140 sq-deg ? 10,000 sq-deg
• Deeper surveys 2000 times more data
• Parameter studies e.g. Cluster model
• More sophisticated analysis e.g. More
  spectral/energy channels

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Where does the Grid come in?

• Speed but sprinting, not marathon
• Get it by
• Parallelization
• Distribution
• Pleasant side effects
• Collaboration
• Logistics
• Monitoring and restart

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Parallelization regions of the sky
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Parallelization regions of the sky
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Parallelization parameter scans
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Parallelization reassembly
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Parallelization data streams
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Distribution file management

• Read from data base or source file or cache
• Written locally or remotely, in one file or
  several
• In ASCII or binary or data base format
• I dont care about any of that

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Distribution execution

• Many opportunities for trouble
• Architecture
• Compiler
• System routines
• Libraries
• Less so with Java, more so with Fortran

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Distribution execution

• Installation the tried and true method, but too
  much work and a shame
• Metadata also a lot of work and not foolproof
• Self-tests recognizes trouble early and
  reliably, but doesnt solve the problems
• Virtual environment???

17
The bottom line

• The main thing I want the grid for is improving
  my top speed.
• I know I have to parallelize my code myself, but
  I want some support doing it.
• I dont want to have to port my code to more than
  one environment.