HP XC System Software Administration Guide Version 2.1

12.11 Enhancing LSF-HPC
You can set environment v ariables to influence the operation o f L SF-HPC in the HP XC system.
These environment variables affect the operation directly and set t hresholds for LSF-HPC
and SLURM interplay.
12.11.1 LSF-HPC Enhancement Settings
Table 12-2 describes the environment variablesthatmaybeusedtoenhanceLSF-HPC.
Table 12-2: Environment Variables for LSF-HPC Enhancement
Environment Variable Description
LSB_SLURM_NONLSF_USE=Y
LSF-HPC is configured to kill unrecognized jobs
in the SLURM lsf partition periodically.
This entry in the lsf.conf file stops LSF-HPC
from periodically killing unrecognized jobs in the
SLURM lsf partition.
LSF_NON_PRIVILEGED_PORTS=Y
Some LSF-HPC communication can occur
through privileged ports. This setting in the
lsf.conf file ensures that no communication
occurs through privileged ports, which helps to
ensure system security.
LSB_SLURM_BESTFIT=Y
This setting in the lsf.conf file provides for
either of two system-wide scheduling modes:
first-fit Under this mode, the scheduler
chooses the first-met free nodes
to allocate.
By default, HPC SLURM
integration works under first-fit
mode.
best-fit Under this mode, the scheduler
applies a set of criteria to choose
nodes with minimal capacities
that satisfy the job request.
You can set
LSB_SLURM_BESTFIT=Y to
switch the scheduler to work
under best-fit mode.
12.11.2 Thresholds in LSF-HPC-SLURM Interplay
When the HP XC system starts, some computer nodes may take a while before they are up. If
LSF-HPC starts to report the current number of CPUs before the system stabilizes, t he smaller
jobs th at are alread y queued are sched uled . It may be b etter to run a larger job requesting
more CPUs.
There are four parame ter s to control when LSF-HP C starts to report total usable C PUs on
HP XC system.
Environment Variable Description
LSF_HPC_NCPU_THRESHOLD=threshold
The threshold parameter is the percentage of
total usable CPUs in LSF partition. The default
value is 80.
LSF-HPC Administration 12-13