11.4. Configuring a resource to prefer its current node

Resources have a resource-stickiness value that you can set as a meta attribute when you create the resource, as described in Configuring resource meta options. The resource-stickiness value determines how much a resource wants to remain on the node where it is currently running. Pacemaker considers the resource-stickiness value in conjunction with other settings (for example, the score values of location constraints) to determine whether to move a resource to another node or to leave it in place.

With a resource-stickiness value of 0, a cluster may move resources as needed to balance resources across nodes. This may result in resources moving when unrelated resources start or stop. With a positive stickiness, resources have a preference to stay where they are, and move only if other circumstances outweigh the stickiness. This may result in newly-added nodes not getting any resources assigned to them without administrator intervention.

Newly-created clusters set the default value for resource-stickiness to 1. This small value can easily be overridden by other constraints that you create, but it is enough to prevent Pacemaker from needlessly moving healthy resources around the cluster. If you prefer cluster behavior that results from a resource-stickiness value of 0, you can change the resource-stickiness default value to 0 with the following command:

# pcs resource defaults update resource-stickiness=0

With a positive resource-stickiness value, no resources will move to a newly-added node. If resource balancing is desired at that point, you can temporarily set the resource-stickiness value to 0.

Note that if a location constraint score is higher than the resource-stickiness value, the cluster may still move a healthy resource to the node where the location constraint points.

For further information about how Pacemaker determines where to place a resource, see Configuring a node placement strategy.