Usage & Fair-Share

• Understanding Your Fair-Share Score

Understanding Your Fair-Share Score

Fair-share is Slurm's mechanism for balancing cluster access across all users and groups. Your fair-share score determines your job priority in the queue relative to other users.

How fair-share works

Every user and account is allocated a target share of the cluster — a fraction of the total resources they are expected to use over time. Slurm tracks actual usage and compares it to the target:

• If you have used less than your share, your priority is higher — your jobs start sooner.
• If you have used more than your share, your priority is lower — other users' jobs take precedence.

Usage decays over time, so a period of heavy use does not permanently lower your priority. The decay window on this cluster is set by HPC staff.

Viewing your fair-share

1. Click Usage in the navbar.
2. The page shows your current fair-share score, your account's usage, and how you compare to other users in your group.

Improving your priority

• Wait — priority increases naturally as past usage decays.
• Use less — avoid requesting more CPUs, memory, or time than your job actually needs. Over-requesting counts as usage even if the resources sit idle.
• Request accurate time limits — a job that requests 24 hours but finishes in 2 hours still accrues 2 hours of usage, but an accurate time limit helps the scheduler backfill other jobs around yours, which benefits everyone.

Checking from the command line

sshare -u $USER

The FairShare column shows your current score. A value close to 1.0 means you are under your target share (high priority); close to 0.0 means you are over it (low priority).