April 18, 2019

Supercharge Your LAN With Condor, part 2 - page 3

Submitting a Basic Condor Job

  • September 25, 2008
  • By Juliet Kemp

Classified Advertisements (ClassAds) are what Condor passes between processes to schedule jobs. There's a ClassAd language, which you can use to specify Requirements and Rank in your job submission file. It's pretty intuitive, especially if you have any experience with C.

Requirements allow you to state what sort of machine attributes you want for your job. So, for example:

requirements = arch == "INTEL" && 
               cpus == "2" &&
               disk == "35000"

specifies an Intel processor machine, with 2 CPUs, and 35,000kB (35 MB) of disk space available for the job. You can specify a number of other things, as well. Note that while the attribute names (arch etc) are case-insensitive, like everything else in the job submit file, the strings (e.g INTEL) are case-sensitive.

Rank allows you to specify which, of the machines that meet your requirements, is the preferred one. You can specify a particular machine or machines:

rank = machine == "client1.example.com"
or just that you want the machine with the best integer performance:
rank = mips

You can check before you specify this how machines are ranked, with the command condor_status -constraint mips - it's worth doing this to check firstly that this information is defined, and secondly that you'll get the machines you expect!

Next steps

The Condor documentation is well worth a read to help you make the most of Condor. You can make your job files much more complicated, and you can experiment with the config settings to get the best options for your setup. The best thing to do is simply to experiment!

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