Platform LSF Administration Guide Version 6.2

Chapter 35
Interactive Jobs with bsub
Administering Platform LSF
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For short to medium-length jobs, the r1m index should be used. For longer jobs, you
might want to add an
r15m threshold. An exception to this are high priority queues,
where turnaround time is more important than total throughput. For high priority
queues, an
r1m scheduling threshold of 2.0 is appropriate.
CPU utilization
(ut)
The ut parameter measures the amount of CPU time being used. When all the CPU
time on a host is in use, there is little to gain from sending another job to that host unless
the host is much more powerful than others on the network. A
ut threshold of 90%
prevents jobs from going to a host where the CPU does not have spare processing
cycles.
If a host has very high
pg but low ut, then it may be desirable to suspend some jobs to
reduce the contention.
Some commands report
ut percentage as a number from 0-100, some report it as a
decimal number between 0-1. The configuration parameter in the
lsf.cluster.cluster_name file and the configuration files take a fraction in the range
from 0 to 1, while the
bsub -R resource requirement string takes an integer from 1-
100.
The command
bhist shows the execution history of batch jobs, including the time
spent waiting in queues or suspended because of system load.
The command
bjobs -p shows why a job is pending.
Scheduling conditions and resource thresholds
Three parameters, RES_REQ, STOP_COND and RESUME_COND, can be specified
in the definition of a queue. Scheduling conditions are a more general way for specifying
job dispatching conditions at the queue level. These parameters take resource
requirement strings as values which allows you to specify conditions in a more flexible
manner than using the
loadSched or loadStop thresholds.