On 04/05/2018 06:45 AM, Andrei Borzenkov wrote: > 04.04.2018 01:35, Ken Gaillot пишет: >> On Tue, 2018-04-03 at 21:46 +0200, Klaus Wenninger wrote: > ... >>>>> -inf constraints like that should effectively prevent >>>>> stonith-actions from being executed on that nodes. >>>> It shouldn't ... >>>> >>>> Pacemaker respects target-role=Started/Stopped for controlling >>>> execution of fence devices, but location (or even whether the >>>> device is >>>> "running" at all) only affects monitors, not execution. >>>> >>>>> Though there are a few issues with location constraints >>>>> and stonith-devices. >>>>> >>>>> When stonithd brings up the devices from the cib it >>>>> runs the parts of pengine that fully evaluate these >>>>> constraints and it would disable the stonith-device >>>>> if the resource is unrunable on that node. >>>> That should be true only for target-role, not everything that >>>> affects >>>> runnability >>> cib_device_update bails out via a removal of the device if >>> - role == stopped >>> - node not in allowed_nodes-list of stonith-resource >>> - weight is negative >>> >>> Wouldn't that include a -inf rule for a node? >> Well, I'll be ... I thought I understood what was going on there. :-) >> You're right. >> >> I've frequently seen it recommended to ban fence devices from their >> target when using one device per target. Perhaps it would be better to >> give a lower (but positive) score on the target compared to the other >> node(s), so it can be used when no other nodes are available. >> > Oh! So I must have misunderstood comments on this in earlier discussions. > > So ability to place stonith resource on node does impact ability to > perform stonith using this resource, right? OTOH decision which node is > eligible to use stonith resource for stonith may not match decision > which node is eligible to start stonith resource? Even more confusing ...
Something like that, yes ... and sorry for the confusion ... Maybe easier to grab: "Has to be able to run there but doesn't actually have to be started there right at the moment" Regards, Klaus >>> It is of course clear that no pengine-decision to start >>> a stonith-resource is required for it to be used for >>> fencing. >>> > This means that there is only subset of usual (co-)locating restrictions > that is taken into account? Is it all documented somewhere? iirc there are restrictions mentioned in the documentation. But what is written there didn't ring the right bells for me- at least not immediately without having a look to the code ;-) So we are working on something easier to grab there. Guess for now the crucial rule is not to use anything that might alter location-rule results over time (attributes, rules with time in them, ...). > _______________________________________________ > Users mailing list: Users@clusterlabs.org > https://lists.clusterlabs.org/mailman/listinfo/users > > Project Home: http://www.clusterlabs.org > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf > Bugs: http://bugs.clusterlabs.org _______________________________________________ Users mailing list: Users@clusterlabs.org https://lists.clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
