LSF Version 7.3 - Platform LSF Configuration Reference

Feature: External load indices
External load indices report the values of dynamic external resources. A dynamic external
resource is a customer-defined resource with a numeric value that changes over time, such as
the space available in a directory. Use the external load indices feature to make the values of
dynamic external resources available to LSF, or to override the values reported for an LSF
built-in load index.
About external load indices
LSF bases job scheduling and host selection decisions on the resources available within your cluster. A resource is a
characteristic of a host (such as available memory) or a cluster (such as the number of shared software licenses) that
LSF uses to make job scheduling and host selection decisions.
A static resource has a value that does not change, such as a host’s maximum swap space. A dynamic resource has a
numeric value that changes over time, such as a host’s currently available swap space. Load indices supply the values
of dynamic resources to a host’s load information manager (LIM), which periodically collects those values.
LSF has a number of built-in load indices that measure the values of dynamic, host-based resources (resources that exist
on a single host)—for example, CPU, memory, disk space, and I/O. You can also define shared resources (resources
that hosts in your cluster share, such as floating software licenses) and make these values available to LSF to use for job
scheduling decisions.
If you have specific workload or resource requirements at your site, the LSF administrator can define external
resources. You can use both built-in and external resources for LSF job scheduling and host selection.
To supply the LIM with the values of dynamic external resources, either host-based or shared, the LSF administrator
writes a site-specific executable called an external load information manager (elim) executable. The LSF administrator
programs the elim to define external load indices, populate those indices with the values of dynamic external resources,
and return the indices and their values to stdout. An elim can be as simple as a small script, or as complicated as a
sophisticated C program.
Note:
LSF does not include a default elim; you should write your own executable to meet
the requirements of your site.
The following illustrations show the benefits of using the external load indices feature. In these examples, jobs require
the use of floating software licenses.
Feature: External load indices
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