The University of Arizona


Condor On CSc Computing Facilities

Condor is developed by the Condor Team at the University of Wisconsin-Madison (UW-Madison), and was first installed as a production system in the UW-Madison Computer Sciences department nearly 10 years ago.

Condor is a specialized batch system for managing compute-intensive jobs. Like most batch systems, Condor provides a queueing mechanism, scheduling policy, priority scheme, and resource classifications. Users submit their compute jobs to Condor, Condor puts the jobs in a queue, runs them, and then informs the user as to the result.

Batch systems normally operate only with dedicated machines. Often termed compute servers, these dedicated machines are typically owned by one organization and dedicated to the sole purpose of running compute jobs. Condor can schedule jobs on dedicated machines. But unlike traditional batch systems, Condor is also designed to effectively utilize non-dedicated machines to run jobs. By being told to only run compute jobs on machines which are currently not being used (no keyboard activity, no load average, no active telnet users, etc), Condor can effectively harness otherwise idle machines throughout a pool of machines. This is important because often times the amount of compute power represented by the aggregate total of all the non-dedicated desktop workstations sitting on people's desks throughout the organization is far greater than the compute power of a dedicated central resource.

Condor has several unique capabilities at its disposal which are geared towards effectively utilizing non-dedicated resources that are not owned or managed by a centralized resource. These include transparent process checkpoint and migration, remote system calls, and ClassAds. Documentation on Condor can be found at

The cy machines (cy01 -- cy05), the Ubuntu machines in GS228 (ub228-01 -- ub228-31), and the RA and TA desktop machines are now running Condor.

To use it, put /opt/condor/bin in your search path. This directory contains the executables that are used to compile and submit programs to Condor.

The directory '/opt/condor/examples' contains example programs written in C, C++, Fortran, and sh. A 'README' file in that directory indicates how to compile and run them. A shell script in that directory called 'submit' will submit these programs so as to be run by Condor.

Not that Condor jobs will *stop* if you open a terminal window and type something into it.

Condor's main function is to make unused computing cycles available to department users. It should be noted that the owner (primary user) of a workstation has priority on its use. For administrative purposes additional people may be given accounts on the workstation, if you're going to do heavy work on someone else's personal workstation without scheduling it through Condor, you should coordinate with them first.

Last updated September 4, 2013, by Tom Lowry
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