Red Hat SummitChapter 9. Pacemaker Rules
Rules can be used to make your configuration more dynamic. One common example is to set one value for
resource-stickiness during working hours, to prevent resources from being moved back to their most preferred location, and another on weekends when no one is around to notice an outage.
Another use of rules might be to assign machines to different processing groups (using a node attribute) based on time and to then use that attribute when creating location constraints.
Each rule can contain a number of expressions, date-expressions and even other rules. The results of the expressions are combined based on the rule's
boolean-op field to determine if the rule ultimately evaluates to true or false. What happens next depends on the context in which the rule is being used.
| Field | Description |
|---|---|
role
| |
score
| |
score-attribute
| |
boolean-op
|
9.1. Node Attribute Expressions
Node attribute expressions are used to control a resource based on the attributes defined by a node or nodes.
| Field | Description |
|---|---|
value
| |
attribute
| |
type
| |
operation
|
The comparison to perform. Allowed values:
*
lt - True if the node attribute’s value is less than value
*
gt - True if the node attribute’s value is greater than value
*
lte - True if the node attribute’s value is less than or equal to value
*
gte - True if the node attribute’s value is greater than or equal to value
*
eq - True if the node attribute’s value is equal to value
*
ne - True if the node attribute’s value is not equal to value
*
defined - True if the node has the named attribute
|
