Friday, June 01, 2007

Using Condor-G Portlets

The Condor-G portlet in the next OGCE release requires a few external steps.
  1. You must install condor (version 6.8), globus, and the OGCE portal server on the same host computer.
  2. You must enable Condor birdbath, as documented on the OGCE web site, http://www.collab-ogce.org/ogce2/condor-job-submission/configuration.html.
  3. You must ensure that Condor-G is enabled in your condor installation. This is probably the case, but see instructions at http://communitygrids.blogspot.com/2006/08/about-condor.html.
  4. You must construct and publish classads for the Grid resources you want to use. The remainder of this post provides basic instructions.

Condor-G uses Condor to act as a client to Globus services. Normally, Condor daemons collect information from the entire condor flock and automatically construct Classads that are used to matchmake your job request to a particular machine. Since Globus services are not part of the flock, you must manually add these to condor on your portal server.

Here is a sample classad for condor-g:

MyType = "Machine"
TargetType = "Job"
Name = "condorTest05"
Machine = "condorTest05"
gatekeeper_url = "login-co.ncsa.teragrid.org/jobmanager"
UpdatesSequenced = 9
CurMatches = 0
Requirements = TARGET.JobUniverse == 9
Rank = 0.000000
CurrentRank = 0.000000
OpSys = "LINUX"
Arch = "INTEL"
State = "Unclaimed"
Activity = "Idle"
LoadAvg = 0.000000
Memory = 2048
WantAdRevaluate = True
StartdIpAddr = "129.79.216.5"

Replace parameters above as appropriate. The StartdIpAddr should be the IP of your portal+condor-g host machine. All other parameters describe the Globus host machine, login-co.ncsa.teragrid.org. Place these values in a file, myCondorClassAd.txt, and then publish this using the command line

[shell-prompt> condor_advertise UPDATE_STARTD_AD myCondorClassAd.txt

This classad will expire in a few minutes, so you will need to execute the above command using a cron script. Rumor has it that better tools for supporting Globus-derived classads exist.

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