Download Moab Cluster Manager User's Guide - E

Chapter 4. Organization
Fairness
Fairshare Policy
Optional
Fairshare is a method of
enforcing cluster sharing
between credentials. A
credential is a user, group,
account, class, or quality of
service (QoS). Fairshare tracks
each credential’s usage for a
desired amount of time and
decreases a job’s start priority if
the fairshare policy is violated.
By decreasing a job’s start
priority, the job will wait longer
in the queue before it starts,
allowing other jobs to execute
first.
• Fairshare Floor Policy - If
the class’s cluster usage is
below the fairshare target,
then the class’s start priority
for the job will increase. The
class’s cluster usage is
measured as the total
percentage amount of the
cluster used by the class.
Fairshare Target Policy- If
the class’s cluster usage is
above or below the fairshare
target, then the class’s start
priority for the job will
increase or decrease
accordingly. The class’s
cluster usage is measured as
the total percentage amount
of the cluster used by the
class.
•
Fairshare Cap Policy - If
the class’s cluster usage is
above the fairshare target,
then the class’s start priority
for the job will decrease. The
class’s cluster usage is
measured as the total
percentage amount of the
cluster used by the class.
•
Absolute Fairshare Policy If a class’s cluster usage
exceeds the fairshare target,
125
then the class’s start priority
for the job will decrease. The
class’s cluster usage is
measured as the total number
•