On 8/10/20 6:47 PM, Ken Gaillot wrote: > Hi all, > > Looking ahead to the Pacemaker 2.0.5 release expected at the end of > this year, here is a new feature already in the master branch. > > When configuring resource operations, Pacemaker lets you set an "on- > fail" policy to specify whether to restart the resource, fence the > node, etc., if the operation fails. With 2.0.5, a new possible value > will be "demote", which will mean "demote this resource but do not > fully restart it". > > "Demote" will be a valid value only for promote actions, and for > recurring monitors with "role" set to "Master". > > Once the resource is demoted, it will be eligible for promotion again, > so if the promotion scores have not changed, a promote on the same node > may be attempted. If this is not desired, the agent can change the > promotion scores either in the failed monitor or the demote. > > The intended use case is an application where a successful demote > assures a well-functioning service, and a full restart would be > unnecessarily heavyweight. A large database might be an example. > > Similarly, Pacemaker offers the cluster-wide "no-quorum-policy" option > to specify what happens to resources when quorum is lost (the default > being to stop them). With 2.0.5, "demote" will be a possible value here > as well, and will mean "demote all promotable resources and stop all > other resources". When using the new "no-quorum-policy" together with SBD please be sure to use an SBD version that has https://github.com/ClusterLabs/sbd/pull/111.
Klaus > > The intended use case is an application that cannot cause any harm > after being demoted, and may be useful in a demoted role even if there > is no quorum. A database that operates read-only when demoted and > doesn't depend on any non-promotable resources might be an example. > > Happy clustering :) _______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
