Condor and the Grid

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Condor and the Grid

• D. Thain, T. Tannenbaum, M. Livny

Christopher M. Moretti 23 February 2007
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Problem Opportunity

• Users need CPUs
• Scientific computing
• Mathematical modeling
• Data mining
• Many CPU cycles are unused
• Personal workstations
• General use laboratories
• Research machines

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Solution Condor

• A hunter of idle workstations
• Keeps track of resources
• needed and available
• Determines and assigns matches
• Monitors progress
• Cleans up and reports results

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Architecture

• Three principals
• Agent machine needing resources
• Matchmaker
• Resource machine lending resources
• Three phases
• Advertising
• Matching/Claiming
• Deploying/Executing

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Advertising
Does Y satisfy X?
MatchMaker
I need X
I have Y

Agent
Lender
idle.cse.nd.edu
needy.cse.nd.edu
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Matching Claiming
MatchMaker
Use idle.cse.nd.edu
Listen for needy.cse.nd.edu

Agent
Lender
Are you still available?
Yes.
idle.cse.nd.edu
needy.cse.nd.edu
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Deploying / Executing
Agent
Lender
Fork!
Fork!
Shadow
Sandbox
Run job J.
J
I need file /tmp/foo.
Split Execution
idle.cse.nd.edu
needy.cse.nd.edu
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Matching

• How are matches determined?
• Policy
• ClassAds
• Why independently claim a match?
• What if the Matchmaker dies?

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ClassAds

• MyTypeJob
• TargetTypeMachine
• Requirements
• ((other.ArchINTELother.OpSysLINUX
• KeyboardIdlegt600))
• Cmd/tmp/a.out
• Ownercmoretti

• MyTypeMachine
• TargetTypeJob
• Machine
• dustpuppy.cse.nd.edu
• Requirements
• ((
• KeyboardIdlegt600
• ))
• ArchINTEL
• OpSysLINUX

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Flocking

• Using another pools resources
• Utilize more total resources
• Find resources that match needs
• Two methods
• Gateway flocking
• Direct flocking

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Gateway Flocking

• Each pool has a known gateway
• Gateways negotiate sharing
• Advertise resources and needs
• Transmit requests to local matchmaker
• Pool-level granularity
• Accounting
• Policy
• Now obsolete

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Gateway Flocking
R
1
MM
A
R
2
Gateway
Gateway
3
4
R
5
MM
R
R
5
R
R
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Direct Flocking

• Agents report to other matchmakers
• No gateways
• Equivalent to being in multiple pools?
• Now the preferred (only) method

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Gateway Flocking
R
MM
A
1
R
2
R
MM
R
R
3
R
R
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Flocking Comparison
Gateway Flocking Direct Flocking

• No gateways
• Individual relationships supported
• Non-transparent
• Fewer organization-level agreements

• Transparency
• Fosters organization-level sharing
• Poor accounting
• Complicated

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Things Arent Perfect

• What happens if (when)
• Matchmaker goes down
• Network or Agent fails during deploy
• Resource or App fails during compute
• Non-dedicated machines.
• How do we keep owners happy?
• What happens when an owner reclaims a resource?

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Total Consumption in 2006
Condor at Notre Dame
http//www.cse.nd.edu/ccl/operations/condor/2005/
users.html
Harnessing Idle Computers with Condor at Notre
Dame Impact on Research in 2006, Douglas Thain
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Current Donors Feb 2007
Owner Nodes CPUs Storage (TB)
CRC/OIT 92 92 3.7
CSE 73 124 11.7
Prof. Thain 59 91 5.5
Prof. Flynn 18 35 0.65
Prof. Striegel 10 20 0.65
Misc 7 17
Total 259 379 20.2 TB
Harnessing Idle Computers with Condor at Notre
Dame Impact on Research in 2006, Douglas Thain
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CPU History
Harnessing Idle Computers with Condor at Notre
Dame Impact on Research in 2006, Douglas Thain
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Recap

• Condor facilitates distributed computation on
  dedicated or scavenged CPUs arranged by a
  matchmaker using ClassAds.
• Split Execution is necessary to fit the jobs
  needs to the environment.
• An agent can advertise to multiple matchmakers to
  examine more potential matches.