Hi all, A recurring request we've seen from Pacemaker users is a feature called "non-critical resources" in a proprietary product and "independent subtrees" in the old rgmanager project.
An example is a large database with an occasionally used reporting tool. The reporting tool is colocated or grouped with the database. If the reporting tool fails enough times to meet its migration-threshold, Pacemaker would traditionally move both resources to another node, to be able to keep them both running. However, the database may be essential, and take a long time to stop and start, whereas the reporting tool may not be that important. So, the user would rather stop the reporting tool in the failure scenario, rather than cause a database outage to move both. With the upcoming Pacemaker 2.1.0, this can be controlled with two new options. Colocation constraints may take a new "influence" option that determines whether the dependent resource influences the location of the main resource, if the main resource is already active. The default of true preserves the previous behavior. Setting it to false makes the dependent resource stop rather than move the main resource. Resources may take a new "critical" meta-attribute that serves as a default for "influence" in all colocation constraints involving the resource as the dependent, as well as all groups involving the resource. In our above example, either the colocation constraint could be marked with influence=false, or the reporting tool resource could be give the meta-attribute critical=false, to achieve the desired effect. A big list of all changes for 2.1.0 can be found at: https://wiki.clusterlabs.org/wiki/Pacemaker_2.1_Changes -- Ken Gaillot <[email protected]> _______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
