Selection string

A shared resource may be used in the resource requirement string of any LSF command. For example, when submitting an LSF job that requires a certain amount of shared scratch space, you might submit the job as follows:

bsub -R "avail_scratch > 200 && swap > 50" myjob

The above assumes that all hosts in the cluster have access to the shared scratch space. The job is only scheduled if the value of the "avail_scratch" resource is more than 200 MB and goes to a host with at least 50 MB of available swap space.

It is possible for a system to be configured so that only some hosts within the LSF cluster have access to the scratch space. To exclude hosts that cannot access a shared resource, the defined(resource_name) function must be specified in the resource requirement string.

For example:

bsub -R "defined(avail_scratch) && avail_scratch > 100 && swap > 100" myjob

would exclude any hosts that cannot access the scratch resource. The LSF administrator configures which hosts do and do not have access to a particular shared resource.

Supported resource names in the defined function

Only resource names configured in lsf.shared, except dynamic NUMERIC resource names with INTERVAL fields defined are accepted as the argument in the defined (resource_name) function.

An exclusive resource may be used in the resource requirement string of any placement or scheduling command, such as bsub, lsplace, lsrun, or lsgrun. An exclusive resource is a special resource that is assignable to a host. This host will not receive a job unless that job explicitly requests the host. For example, use the following command to submit a job requiring the exclusive resource bigmem:

bsub -R "bigmem" myjob

Jobs will not be submitted to the host with the bigmem resource unless the command uses the -R option to explicitly specify "bigmem".

To configure an exclusive resource, first define a static Boolean resource in lsf.shared. For example:

Begin Resource
...
bigmem Boolean () ()
End Resource

Assign the resource to a host in the Host section of lsf.cluster.cluster_name for static hosts or LSF_LOCAL_RESOURCES for dynamic hosts. Prefix the resource name with an exclamation mark (!) to indicate that the resource is exclusive to the host. For example:

Begin Host
HOSTNAME   model  type  server r1m pg tmp RESOURCES       RUNWINDOW
...
hostE      !      !     1      3.5 () ()  (linux !bigmem) ()
...
End Host
 
LSF_LOCAL_RESOURCES="[resource linux] [!bigmem]"

When LSF_STRICT_RESREQ=Y is configured in lsf.conf, resource requirement strings in select sections must conform to a more strict syntax. The strict resource requirement syntax only applies to the select section. It does not apply to the other resource requirement sections (order, rusage, same, span, or cu). When LSF_STRICT_RESREQ=Y in lsf.conf, LSF rejects resource requirement strings where an rusage section contains a non-consumable resource.

Strict select string syntax usage notes

The strict syntax is case-sensitive.

&& || !

= == != < > <= >=

defined(   mg   )

!!mg

!(!mg)

type==any rusage[mem=1024]
select[type==any] rusage[mem=1024]
select[type==any]rusage[mem=1024]

type==anyrusage[mem=1024]

select[mem>0] select[maxmem>0]

Escape characters (like '\n') are not supported in string literals.

A colon (:) is not allowed inside the select string. For example, select[mg:bigmem] is not correct.

inf and nan can be used as resource names or part of a resource name.

Single or double quotes are only supported around the whole resource requirement string, not within the square brackets containing the selection string. For example, in lsb.queues, RES_REQ='swp>100' and RES_REQ="swp>100" are correct. Neither RES_REQ=select['swp>100'] nor RES_REQ=select["swp>100"] are supported.

Explicit and implicit select sections

An explicit select section starts from the section keyword and ends at the begin of next section, for example: the select section is select[selection_string]. An implicit select section starts from the first letter of the resource requirement string and ends at the end of the string if there are no other resource requirement sections. If the resource requirement has other sections, the implicit select section ends before the first letter of the first section following the selection string.

All explicit sections must begin with a section keywords (select, order, span rusage, or same). The resource requirement content is contained by square brackets ([) and (]).

An implicit select section must be the first resource requirement string in the whole resource requirement specification. Explicit select sections can appear after other sections. A resource requirement string can have only one select section (either an explicit select section or an implicit select section). A section with an incorrect keyword name is not a valid section.

Examples

Check resource requirement syntax

Use the BSUB_CHK_RESREQ environment variable to check the compatibility of your existing resource requirement select strings against the stricter syntax enabled by LSF_STRICT_RESREQ=Y in lsf.conf.

Set the BSUB_CHK_RESREQ environment variable to any value enable bsub to check the syntax of the resource requirement selection string without actually submitting the job for scheduling and dispatch. LSF_STRICT_RESREQ does not need to be set to check the resource requirement selection string syntax.

bsub only checks the select section of the resource requirement. Other sections in the resource requirement string are not checked.

bsub -R "select[type==local] select[hname=abc]" sleep 10
Error near "select": duplicate section. Job not submitted.
echo $?
255

env | grep BSUB_CHK_RESREQ
BSUB_CHK_RESREQ=1
bsub -R "select[type==local]" sleep 10
Resource requirement string is valid.
echo $?
0

bsub sleep 120
Resource requirement string is valid.
echo $?
0

bsub -ar -app <appplicaion_file> -n "1,100" -R "rusage[swp=100,license=1]" myjob

Every time the job grows in slots, slots are requested on hosts of the specified type.