8.7. Ensuring Time-Based Rules Take Effect
A Pacemaker cluster is an event-driven system. As such, it won’t recalculate the best place for resources to run unless something (like a resource failure or configuration change) happens. This can mean that a location constraint that only allows resource X to run between 9am and 5pm is not enforced.
If you rely on time-based rules, the cluster-recheck-interval
cluster option (which defaults to 15 minutes) is essential. This tells the cluster to periodically recalculate the ideal state of the cluster.
For example, if you set cluster-recheck-interval="5m"
, then sometime between 09:00 and 09:05 the cluster would notice that it needs to start resource X, and between 17:00 and 17:05 it would realize that X needed to be stopped. The timing of the actual start and stop actions depends on what other actions the cluster may need to perform first.