Administering Platform LSF - SAS

Chapter 14
Fairshare Scheduling
Hierarchical Fairshare
About hierarchical fairshare
For both queue and host partitions, hierarchical fairshare lets you allocate
resources to users in a hierarchical manner.
By default, when shares are assigned to a group, group members compete for
resources according to FCFS policy. If you use hierarchical fairshare, you
control the way shares that are assigned collectively are divided among group
members.
If groups have subgroups, you can configure additional levels of share
assignments, resulting in a multi-level share tree that becomes part of the
fairshare policy.
How hierarchical fairshare affects dynamic share priority
When you use hierarchical fairshare, the dynamic share priority formula does
not change, but LSF measures the resource consumption for all levels of the
share tree. To calculate the dynamic priority of a group, LSF uses the resource
consumption of all the jobs in the queue or host partition that belong to users
in the group and all its subgroups, recursively.
How hierarchical fairshare affects job dispatch order
LSF uses the dynamic share priority of a user or group to find out which user's
job to run next. If you use hierarchical fairshare, LSF works through the share
tree from the top level down, and compares the dynamic priority of users and
groups at each level, until the user with the highest dynamic priority is a single
user, or a group that has no subgroups.
Viewing hierarchical share information for a group
Use bugroup -l to find out if you belong to a group, and what the share
distribution is.
This command displays all the share trees that are configured, even if they are
not used in any fairshare policy.
Example % bugroup -l
GROUP_NAME: group1
USERS: group2/ group3/
SHARES: [group2,20] [group3,10]
GROUP_NAME: group2
USERS: user1 user2 user3
SHARES: [others,10] [user3,4]
GROUP_NAME: group3
USERS: all
SHARES: [user2,10] [default,5]
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