Administering Platform LSF - SAS

Memory Reservation for Pending Jobs
Memory Reservation for Pending Jobs
About memory reservation for pending jobs
By default, the rusage string reserves resources for running jobs. Because
resources are not reserved for pending jobs, some memory-intensive jobs
could be pending indefinitely because smaller jobs take the resources
immediately before the larger jobs can start running. The more memory a job
requires, the worse the problem is.
Memory reservation for pending jobs solves this problem by reserving memory
as it becomes available, until the total required memory specified on the
rusage string is accumulated and the job can start. Use memory reservation
for pending jobs if memory-intensive jobs often compete for memory with
smaller jobs in your cluster.
Configuring memory reservation for pending jobs
RESOURCE_RESERVE parameter
Use the RESOURCE_RESERVE parameter in lsb.queues to reserve host
memory for pending jobs.
The amount of memory reserved is based on the currently available memory
when the job is pending. Reserved memory expires at the end of the time
period represented by the number of dispatch cycles specified by the value of
MAX_RESERVE_TIME set on the RESOURCE_RESERVE parameter.
Configure
lsb.modules
Configure
lsb.queues
Example queues
To enable memory reservation for sequential jobs, add the LSF scheduler
plugin module name for resource reservation (schmod_reserve) to the
lsb.modules file:
Begin PluginModule
SCH_PLUGIN
RB_PLUGIN
SCH_DISABLE_PHASES
schmod_default () ()
schmod_reserve () ()
schmod_preemption () ()
End PluginModule
Set the RESOURCE_RESERVE parameter in a queue defined in lsb.queues.
If both RESOURCE_RESERVE and SLOT_RESERVE are defined in the same
queue, job slot reservation and memory reservation are both enabled and an
error is displayed when the cluster is reconfigured. SLOT_RESERVE is ignored.
The following queue enables memory reservation for pending jobs:
Begin Queue
QUEUE_NAME = reservation
DESCRIPTION = For resource reservation
PRIORITY=40
RESOURCE_RESERVE = MAX_RESERVE_TIME[20]
End Queue
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Administering Platform LSF