Administering Platform LSF - SAS

Submitting and Controlling Chunk Jobs
WAIT status
Chapter 24
Chunk Job Dispatch
When a job is submitted to a queue configured with the CHUNK_JOB_SIZE
parameter, LSF attempts to place the job in an existing chunk. A job is added
to an existing chunk if it has the same characteristics as the first job in the
chunk:
◆ Submitting user
◆ Resource requirements
◆ Host requirements
◆ Queue
If a suitable host is found to run the job, but there is no chunk available with
the same characteristics, LSF creates a new chunk.
Resources reserved for any member of the chunk are reserved at the time the
chunk is dispatched and held until the whole chunk finishes running. Other
jobs requiring the same resources are not dispatched until the chunk job is
done.
For example, if all jobs in the chunk require a software license, the license is
checked out and each chunk job member uses it in turn. The license is not
released until the last chunk job member is finished running.
When sbatchd receives a chunk job, it will not start all member jobs at once.
A chunk job occupies a single job slot. Even if other slots are available, the
chunk job members must run one at a time in the job slot they occupy. The
remaining jobs in the chunk that are waiting to run are displayed as WAIT by
bjobs. Any jobs in WAIT status are included in the count of pending jobs by
bqueues and busers. The bhosts command shows the single job slot
occupied by the entire chunk job in the number of jobs shown in the NJOBS
column.
The bhist -l command shows jobs in WAIT status as Waiting ...
The bjobs -l command does not display a WAIT reason in the list of pending
jobs.
Administering Platform LSF 327