LSF Version 7.3 - Administering Platform LSF

Administering Platform LSF 33
How the System Works
Automatic queue selection
Typically, a cluster has multiple queues. When you submit a job to LSF you might
define which queue the job will enter. If you submit a job without specifying a queue
name, LSF considers the requirements of the job and automatically chooses a
suitable queue from a list of candidate default queues. If you did not define any
candidate default queues, LSF will create a new queue using all the default settings,
and submit the job to that queue.
Viewing default
queues
Use bparams to display default queues:
bparams
Default Queues: normal
...
The user can override this list by defining the environment variable
LSB_DEFAULTQUEUE.
How automatic
queue selection
works
LSF selects a suitable queue according to:
◆ User access restriction—Queues that do not allow this user to submit jobs are
not considered.
◆ Host restriction—If the job explicitly specifies a list of hosts on which the job
can be run, then the selected queue must be configured to send jobs to all hosts
in the list.
◆ Queue status—Closed queues are not considered.
◆ Exclusive execution restriction—If the job requires exclusive execution, then
queues that are not configured to accept exclusive jobs are not considered.
◆ Job’s requested resources—These must be within the resource allocation limits
of the selected queue.
If multiple queues satisfy the above requirements, then the first queue listed in the
candidate queues (as defined by the DEFAULT_QUEUE parameter or the
LSB_DEFAULTQUEUE environment variable) that satisfies the requirements is
selected.
Job files
When a batch job is submitted to a queue, LSF Batch holds it in a job file until
conditions are right for it to be executed. Then the job file is used to execute the job.
UNIX The job file is a Bourne shell script run at execution time.
Windows The job file is a batch file processed at execution time.