Administering Platform LSF - SAS

Chapter 13
Specifying Resource Requirements
Same String
You must have the parallel batch job scheduler plugin installed in order to use the
same string.
Syntax
Examples
Parallel jobs run on multiple hosts. If your cluster has heterogeneous hosts,
some processes from a parallel job may for example, run on Solaris and some
on SGI IRIX. However, for performance reasons you may want all processes of
a job to run on the same type of host instead of having some processes run on
one type of host and others on another type of host.
The same string specifies that all processes of a parallel job must run on hosts
with the same resource.
You can specify the same string:
◆ At the job level in the resource requirement string of:
❖ bsub
❖ bmod
◆ At the queue-level in lsb.queues in the RES_REQ parameter.
When both queue-level and job-level same sections are defined, LSF combines
both requirements to allocate processors.
resource_name[:resource_name]...
You can specify any static resource.
When you specify for example, resource1:resource2, if hosts always have
both resources, the string is interpreted as:
◆ Allocate processors only on hosts that have the same value for resource1
and the same value for resource2
If hosts do not always have both resources, it is interpreted as:
◆ Allocate processors either on hosts that have the same value for
resource1, or on hosts that have the same value for resource2, or on
hosts that have the same value for both resource1 and resource2
% bsub -n 4 -R"select[type==SGI6 || type==SOL7] same[type]"
myjob
Run all parallel processes on the same host type. Allocate 4 processors on the
same host type—either SGI IRIX, or Solaris 7, but not both.
% bsub -n 6 -R"select[type==any] same[type:model]" myjob
Run all parallel processes on the same host type and model. Allocate 6
processors on any host type or model as long as all the processors are on the
same host type and model.
Administering Platform LSF 199