ClassAds: Present and Future

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ClassAdsPresent and Future
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What Are ClassAds?

• A ClassAd maps attributes to expressions
• Expressions
• Constants strings, numbers, etc.
• Expressions other.Memory gt 600M
• Lists roy, pfc, melski
• Other ClassAds
• Powerful tool for grid computing
• Semi-structured (you pick your structure)
• Matchmaking

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ClassAd Example

• Type Job
• Owner roy
• Universe Standard
• Requirements (other.OpSys Linux
  other.DiskSpace gt 140M)
• Rank (other.DiskSpace gt 300M ? 10 1)
• ClusterID 12314
• JobID 0
• Env
• (To see a real ClassAd, try condor_q l or
  condor_status l)

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ClassAd Matchmaking

• Type Job
• Owner roy
• Requirements (other.OpSys Linux
  other.DiskSpace gt 140M)
• Rank (other.DiskSpace gt 300M ? 10 1)
• Type Machine
• OpSys Linux
• DiskSpace 500M
• AllowedUsers roy, melski, pfc
• Requirements (IsMember(other.Owner,
  AllowedUsers)

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ClassAds Are Open Source

• Library GNU Public License (LGPL)
• Complete source code included
• Library code
• Test program
• Available from
• http//www.cs.wisc.edu/condor/classad
• Version 0.9.3

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Who Uses ClassAds?

• Condor
• European Data Grid
• NeST
• Web site
• You?

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ClassAd User Condor

• ClassAds describe jobs and machines
• Matchmaking figures out what jobs run on which
  machines
• DAGMan will soon internally represent DAGs as
  ClassAds

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ClassAd User EU Datagrid

• JDL ClassAd schema to describe jobs/machines
• ResourceBroker matches jobs to machines

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ClassAd User NeST

• NeST is a storage appliance
• NeST uses ClassAd collections for persistent
  storage of
• User Information
• File meta-data
• Disk Information
• Lots (storage space allocations)

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ClassAd User Web Site

• Web-based application in Germany
• User actions (transitions) are constrained
• Constraints expressed through ClassAds

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Whats New?

• ClassAd collections
• XML representation

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New ClassAd Collections

• A collection is a bag of ClassAds
• Can have views on a collection
• Sub view contains ClassAds matching a
  constraint, like (memory gt 300M)
• Partition view contains sub view for each value
  of a constraint

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Collection Views
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New XML Representation

• Does not replace original representation
• Sample
• ltclassadgt
• ltattribute nameTypegtltstringgtJoblt/stringgtlt/attri
  butegt
• ltattribute nameOwnergtltstringgtRoylt/stringgtlt/attr
  ibutegt
• ltattribute nameRequirementsgtltexprgt(other.Memory
  gt 600M) lt/exprgtlt/attributegt
• lt/classadgt

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Whats Coming?

• 1.0real soon now
• Smoothing out minor issues
• Updated documentation
• After 1.0
• Set-extensions (with University of Chicago)
• Gang-matching, indexing
• Recoverable transmission of ClassAds (two-phase
  commit)
• Access from multiple languages (SWIG)

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Cool! Tell Me More!

• QA 900am-noon, Wed., Room 3393
• http//www.cs.wisc.edu/condor/classad
• condor-admin_at_cs.wisc.edu
• ClassAd users mailing list