Administering Platform LSF - SAS

Chapter 14
Fairshare Scheduling
Configuring a share tree
Example
Group membership is already defined in the UserGroup section of
lsb.users. To configure a share tree, use the USER_SHARES column to
describe how the shares are distributed in a hierachical manner. Use the
following format.
Begin UserGroup
GROUP_NAME GROUP_MEMBER USER_SHARES
GroupB (User1 User2) ()
GroupC (User3 User4) ([User3, 3] [User4, 4])
GroupA (GroupB GroupC User5) ([User5, 1] [default, 10])
End UserGroup
◆ User groups must be defined before they can be used (in the
GROUP_MEMBER column) to define other groups.
◆ Enclose the share assignment list in parentheses, as shown, even if you do
not specify any user share assignments.
An Engineering queue or host partition organizes users hierarchically, and
divides the shares as shown. It does not matter what the actual number of
shares assigned at each level is.
Engineering
25% 50% 25%
Technical
Support
Development Research
50% 35% 15% 80% 20%
Test Application Systems Chip X Chip Y
50% 50% 80% 20%
User 1 User 2 User 3 User 4
The Development group will get the largest share (50%) of the resources in the
event of contention. Shares assigned to the Development group can be further
divided among the Systems, Application and Test groups which receive 15%,
35%, and 50%, respectively. At the lowest level, individual users compete for
these shares as usual.
One way to measure a user’s importance is to multiply their percentage of the
resources at every level of the share tree. For example, User1 is entitled to 10%
of the available resources (.50 x .80 x .25 = .10) and User3 is entitled to 4%
(.80 x .20 x .25 = .04). However, if Research has the highest dynamic share
priority among the 3 groups at the top level, and ChipY has a higher dynamic
priority than ChipX, the next comparison is between User3 and User4, so the
importance of User1 is not relevant. The dynamic priority of User1 is not even
calculated at this point.
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