Platform LSF Administration Guide Version 6.2

Chapter 1
About Platform LSF
Administering Platform LSF
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To schedule a job on a host, the load levels on that host must satisfy both the thresholds
configured for that host and the thresholds for the queue from which the job is being
dispatched.
The value of a load index may either increase or decrease with load, depending on the
meaning of the specific load index. Therefore, when comparing the host load conditions
with the threshold values, you need to use either greater than (>) or less than (<),
depending on the load index.
Commands
◆ bhosts-l—View suspending conditions for hosts
◆ bqueues -l—View suspending conditions for queues
◆ bjobs -l—View suspending conditions for a particular job and the scheduling
thresholds that control when a job is resumed
Configuration
◆ lsb.bhosts—Configure thresholds for hosts
◆ lsb.queues—Configure thresholds for queues
Runtime resource
usage limits
Limit the use of resources while a job is running. Jobs that consume more than the
specified amount of a resource are signalled or have their priority lowered.
Configuration
◆ lsb.queues—Configure resource usage limits for queues
Hard and soft
limits
Resource limits specified at the queue level are hard limits while those specified with job
submission are soft limits. See
setrlimit(2) man page for concepts of hard and soft
limits.
Resource
allocation limits
Restrict the amount of a given resource that must be available during job scheduling for
different classes of jobs to start, and which resource consumers the limits apply to. If all
of the resource has been consumed, no more jobs can be started until some of the
resource is released.
Configuration
◆ lsb.resources—Configure queue-level resource allocation limits for hosts,
users, queues, and projects
Resource
requirements
(bsub -R)
Restrict which hosts the job can run on. Hosts that match the resource requirements are
the candidate hosts. When LSF schedules a job, it collects the load index values of all the
candidate hosts and compares them to the scheduling conditions. Jobs are only
dispatched to a host if all load values are within the scheduling thresholds.
Commands
◆ bsub-R—Specify resource requirement string for a job
Configuration
◆ lsb.queues—Configure resource requirements for queues