Static and Dynamic Resource Quotas

Resource quota rules always define a maximum value of a resource that can be used. In most cases, these values are static and equal for all matching filter scopes. Although you could define several different rules to apply to different scopes, you would then have several rules that are nearly identical. Instead of duplicating rules, you can instead define a dynamic limit.

A dynamic limit uses an algebraic expression to derive the rule limit value. The algebraic formula can reference a complex attribute whose value is used to calculate the resulting limit.

Example 6–2 Dynamic Limit Example

The following example illustrates the use of dynamic limits. Users are allowed to use 5 slots per CPU on all Linux hosts.

limit hosts {@linux_hosts} to slots=$num_proc*5

The value of num_proc is the number of processors on the host. The limit is calculated by the formula $num_proc*5, and can be different on each host. Expanding the example above, you could have the following resulting limits:

• On a host that has two CPUs, users can use ten slots to run jobs.

• On a host that has one CPU, users can use only five slots to run jobs.

Instead of num_proc, you could use any other complex attribute known for a host as either a load value or a consumable resource.