Priorities and Preemption

Job priorities enable you to assign a priority level to each submitted Condor job. Job priorities, however, do not impact user priorities.

User priorities are linked to the allocation of Condor resources based upon a user's priority. A lower numerical value for user priority means higher priority, so a user with priority 5 is allocated more resources than a user with priority 50. You can view user priorities by using the condor_userprio command. For example:

> condor_userprio -allusers

Condor continuously calculates the share of available machines. For example, a user with a priority of 10 is allocated twice as many machines as a user with a priority of 20. New users begin with a priority of 0.5 and, based upon increased usage, their priority rating rises proportionately in relation to other users. Condor enforces this function such that each user gets a fair share of machines according to user priority and historical volume. For example, if a low-priority user is using all available machines and a higher-priority user submits a job, Condor immediately performs a checkpoint and vacates the jobs that belong to the lower-priority user, except for that user's last job.

User priority rating decreases over time and returns to a baseline of 0.5 as jobs are completed and idle time is realized relative to other users.