LSF Version 7.3 - Platform LSF Configuration Reference

lsb.applications) of both submission cluster and execution cluster. LSF uses the directory
specified in the execution cluster.
To make a MultiCluster job checkpointable, both submission and execution queues must
enable checkpointing, and the application profile or queue setting on the execution cluster
determines the checkpoint directory. Checkpointing is not supported if a job runs on a leased
host.
Default
Not defined
CHUNK_JOB_SIZE
Syntax
CHUNK_JOB_SIZE=integer
Description
Chunk jobs only. Enables job chunking and specifies the maximum number of jobs allowed
to be dispatched together in a chunk. Specify a positive integer greater than 1.
The ideal candidates for job chunking are jobs that have the same host and resource
requirements and typically take 1 to 2 minutes to run.
Job chunking can have the following advantages:
•
Reduces communication between sbatchd and mbatchd and reduces scheduling overhead
in mbschd.
•
Increases job throughput in mbatchd and CPU utilization on the execution hosts.
However, throughput can deteriorate if the chunk job size is too big. Performance may decrease
on queues with CHUNK_JOB_SIZE greater than 30. You should evaluate the chunk job size
on your own systems for best performance.
With MultiCluster job forwarding model, this parameter does not affect MultiCluster jobs
that are forwarded to a remote cluster.
Compatibility
This parameter is ignored in the following kinds of queues and applications:
•
Interactive (INTERACTIVE=ONLY parameter)
•
CPU limit greater than 30 minutes (CPULIMIT parameter)
•
Run limit greater than 30 minutes (RUNLIMIT parameter)
•
Runtime estimate greater than 30 minutes (RUNTIME parameter in
lsb.applications only)
If CHUNK_JOB_DURATION is set in lsb.params, chunk jobs are accepted regardless of
the value of CPULIMIT, RUNLIMIT or RUNTIME.
Example
The following configures a queue named chunk, which dispatches up to 4 jobs in a chunk:
Begin Queue
QUEUE_NAME = chunk
PRIORITY = 50
lsb.queues
284 Platform LSF Configuration Reference