About external host and user groups

LSF provides you with the option to configure host groups, user groups, or both. When the membership of a host or user group changes frequently, or when the group contains a large number of members, you can use an external executable called egroup to retrieve a list of members rather than having to configure the group membership manually. You can write a site-specific egroup executable that retrieves host or user group names and the hosts or users that belong to each group.

You can write your egroup executable to retrieve group members for:

One or more host groups
One or more user groups
Any combination of host and user groups

LSF does not include a default egroup; you should write your own executable to meet the requirements of your site.

Default behavior (feature not enabled)

The following illustrations show the benefits of using the external host and user groups feature.

With external host and user groups enabled

Scope

Applicability	Details
Operating system	UNIX Windows A mix of UNIX and Windows hosts
Dependencies	UNIX and Windows user accounts must be valid on all hosts in the cluster and must have the correct permissions to successfully run jobs. The cluster must be reconfigured if you want to run the egroup executable to retrieve host or user group members. With a time interval specified in EGROUP_UPDATE_INTERVAL, egroup members can be updated automatically.
Limitations	The egroup executable works with static hosts only; you cannot use an egroup executable to add a dynamically added host to a host group.
Not used with	Host groups when you have configured EGO-enabled service-level agreement (SLA) scheduling because EGO resource groups replace LSF host groups.