GridLab WP2 Cactus GAT CGAT

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GridLab WP-2Cactus GAT (CGAT)
Ed Seidel, AEI LSU Co-chair, GGF Apps RG,
Gridstart Apps TWG Gabrielle Allen, Robert Engel,
Tom Goodale, Thomas Radke Others from WP-1
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Vision

• Goal enable all Cactus apps to use GAT for Grid
  scenarios.
• Very important WP, prototyped in first year, now
  being fully developed as GAT implementation in
  first full release
• Cactus (http//www.cactuscode.org)
• Leading application framework used by dozens of
  groups in astrophysics (EU Network), climate,
  CFD, numerical relativity, bio-informatics
• Used for many years for in (pre)Grid
  environments, and is commonly deployed for
  demonstrations of the use of the Grid
• Previously used hand-crafted Cactus modules,
  ad-hoc mechanisms, relying on the authors'
  extensive experience of Grid computing
• The CGAT work aims to replace this using
  functionality available through the GAT API
• Exemplar modules for other Cactus apps, worked
  example for others

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Dynamic Grid Computing

• Migration Cactus Worm demonstrated SC00
• Launch Job
• Run awhile, write checkpoint
• Migrate itself to next site
• Register new location to
• User tracks/steers
• Proof of concept, but dirty hack
• Created our community!
• Spawning SC01
• User invokes Spawner
• Analysis tasks outsourced
• Globus enabled login, data transfer
• It worked!

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Conceptual View
CGAT
Cactus Flesh
Thorn
GAT
Thorn
Thorn
Thorn
Thorn
GridLab Service
Application Thorns
GridLab Service

• CGAT consists of a set of thorns, linked to GAT
  Engine, which provide services to Cactus
  applications. The vast majority of Cactus thorns
  will be unaware of the CGAT or GAT.

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CGAT Functionality

• Ability to remote trigger app checkpoint,
  retrieve checkpoint file, and stage it to a new
  host
• Provide performance and other data to external
  applications using GAT monitoring infrastructure.
• Export list of application-created files via GAT
  advert and/or replica functionality, through
  generic advertising service
• Query information about the current machine, such
  as cache size, memory size, size of file-systems,
  name of machine.
• Spawning of tasks, e.g. for task farming,
  monitoring status.
• Automated/triggered announcement of app events,
  such as app startup, reaching particular
  iteration, termination, etc.
• Etc Working with app communities to determine
  need GGF, Gridstart TWG, other projects

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Status

• SC03 thorns were written with prototype GAT
  Engine to enable the GridLab migration scenario
• Remote monitoring of the status of the running
  Cactus application
• Triggering of Cactus checkpointing
• Advertisement of Cactus checkpointing data
• Now thorns converted to use the new GAT
  implementation and the specified GAT API
• Will be demonstrated at this review and at GGF
  this week
• Any application in Cactus can take advantage of
  this without any other modification
• E.g., Black Holes on regular meshes, CFD on
  unstructured meshes (planned), ocean-atmosphere
  modeling

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Some Specifics

• Gridmake https//sourceforge.net/projects/gridmak
  e/
• Distribute/compile source code on an arbitrary
  number of machines
• Needed for GridLab migration, Cactus remote
  testing, creation of executables for MPI
  simulations across multiple machines
• Good for codes with configurable make
  environments, machine configuration scripts, use
  of CVS etc.
• Developed using public key infrastructure, soon
  as a grid service
• To be incorporated as a GridSphere portlet
• Thorn_cgat
• Initializes GAT
• Registers that this is checkpointable app with
  grms
• Receives requests from grms (or any broker)
• Steers cactus parameter to initiate checkpoint
• Reports on success of checkpoint

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Near Future

• Review current thorns, make production versions,
  distribute
• Add remaining functionality
• Work with AEI/LSU numerical relativity group
• ensure correct functionality
• train on use of CGAT infrastructure
• develop task farming infrastructure for physics
  surveys
• Deploy across GridLab testbed and LSU-AEI-KISTI
  Grid
• Work with other Cactus app groups in
  astrophysics, climate, CFD, bioinformatics,
  others NSF and DOE projects in US
• New, experienced personnel just added now that
  GAT ready