LSF Version 7.3 - Administering Platform LSF

Cluster Concepts
24 Administering Platform LSF
◆ bhosts -l—View load levels on a host
External load
indices
Defined and configured by the LSF administrator and collected by an External
Load Information Manager (ELIM) program. The ELIM also updates LIM when
new values are received.
Commands:
◆ lsinfo—View external load indices
Static resources Built-in resources that represent host information that does not change over time,
such as the maximum RAM available to user processes or the number of processors
in a machine. Most static resources are determined by the LIM at start-up time.
Static resources can be used to select appropriate hosts for particular jobs based on
binary architecture, relative CPU speed, and system configuration.
Load thresholds Two types of load thresholds can be configured by your LSF administrator to
schedule jobs in queues. Each load threshold specifies a load index value:
◆ loadSched determines the load condition for dispatching pending jobs. If a
host’s load is beyond any defined
loadSched, a job will not be started on the
host. This threshold is also used as the condition for resuming suspended jobs.
◆ loadStop determines when running jobs should be suspended.
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.hosts—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.