On Thu, 2024-10-17 at 16:34 +0200, Jochen wrote: > Thanks for the help! > > Before I break out my editor and start writing custom resource > agents, one question: Is there a way to use a cloned > ocf:pacemaker:attribute resource to set a clone-specific attribute on > a node? I.e. attribute "started-0=1" and "started-1=1", depending on > the clone ID? For this I would need e.g. a rule to configure a clone > specific resource parameter, or is there something like variable > substitution in resource parameters?
No, ocf:pacemaker:attribute won't work properly as a unique clone. If one instance is started and another stopped, it will get the status of one of them wrong. I noticed that yesterday and came up with an idea for a general solution if you feel like tackling it: https://projects.clusterlabs.org/T899 > > > On 16. Oct 2024, at 16:22, Ken Gaillot <kgail...@redhat.com> wrote: > > > > On Mon, 2024-10-14 at 18:49 +0200, Jochen wrote: > > > Hi, I have two cloned resources in my cluster that have the > > > following > > > properties: > > > > > > * There are a maximum of two instances of R1 in the cluster, with > > > a > > > maximum of two per node > > > * When any instance of R1 is started on a node, exactly one > > > instance > > > of R2 should run on that node > > > > > > When I configure this, and verify the configuration with > > > "crm_verify > > > -LV", I get the following error: > > > > > > clone_rsc_colocation_rh) error: Cannot interleave R2-clone and > > > R1-clone because they do not support the same number of instances > > > per > > > node > > > > > > How can I make this work? Any help would be greatly appreciated. > > > > Hi, > > > > I believe the number of instances has to be the same because each > > instance pair on a single node is interleaved. > > > > There's no direct way to configure what you want, but it might be > > possible with a custom OCF agent for R1 and attribute-based rules. > > > > On start, the R1 agent could set a custom node attribute to some > > value. > > On stop, it could check whether any other instances are active > > (assuming that's possible), and if not, clear the attribute. Then, > > R2 > > could have a location rule enabling it only on nodes where the > > attribute has the desired value. > > > > R2 wouldn't stop until *after* the last instance of R1 stops, which > > could be a problem depending on the particulars of the service. > > There > > might also be a race condition if two instances are stopping at the > > same time, so it might be worthwhile to set ordered=true on the > > clone. > > > > > > > > Current configuration is as follows: > > > > > > <resources> > > > <clone id="R1-clone"> > > > <meta_attributes id="R1-clone-meta_attributes"> > > > <nvpair name="interleave" value="true" id="R1-clone- > > > meta_attributes-interleave"/> > > > <nvpair name="resource-stickiness" value="0" id="R1-clone- > > > meta_attributes-resource-stickiness"/> > > > <nvpair name="clone-max" value="2" id="R1-clone- > > > meta_attributes-clone-max"/> > > > <nvpair name="clone-node-max" value="2" id="R1-clone- > > > meta_attributes-clone-node-max"/> > > > <nvpair name="globally-unique" value="true" id="R1-clone- > > > meta_attributes-globally-unique"/> > > > <nvpair name="failure-timeout" value="300" id="R1-clone- > > > meta_attributes-failure-timeout"/> > > > <nvpair name="migration-threshold" value="0" id="R1-clone- > > > meta_attributes-migration-threshold"/> > > > <nvpair id="R1-clone-meta_attributes-target-role" > > > name="target- > > > role" value="Stopped"/> > > > </meta_attributes> > > > </clone> > > > <clone id="R2-clone"> > > > <meta_attributes id="R2-clone-meta_attributes"> > > > <nvpair name="interleave" value="true" id="R2-clone- > > > meta_attributes-interleave"/> > > > <nvpair name="resource-stickiness" value="0" id="R2-clone- > > > meta_attributes-resource-stickiness"/> > > > <nvpair name="failure-timeout" value="300" id="R2-clone- > > > meta_attributes-failure-timeout"/> > > > <nvpair name="migration-threshold" value="0" id="R2-clone- > > > meta_attributes-migration-threshold"/> > > > <nvpair id="R2-clone-meta_attributes-target-role" > > > name="target- > > > role" value="Stopped"/> > > > </meta_attributes> > > > </clone> > > > </resources> > > > > > > <constraints> > > > <rsc_order id="R1-order" kind="Mandatory" first="R1-clone" > > > then="R2-clone"/> > > > <rsc_colocation id="R2-clone-colocation" score="INFINITY" > > > rsc="R2- > > > clone" with-rsc="R1-clone"/> > > > </constraints> > > > > > > > > -- > > Ken Gaillot <kgail...@redhat.com> > > > > _______________________________________________ > > Manage your subscription: > > https://lists.clusterlabs.org/mailman/listinfo/users > > > > ClusterLabs home: https://www.clusterlabs.org/ > > _______________________________________________ > Manage your subscription: > https://lists.clusterlabs.org/mailman/listinfo/users > > ClusterLabs home: https://www.clusterlabs.org/ -- Ken Gaillot <kgail...@redhat.com> _______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
