[ClusterLabs] Colocation dependencies (dislikes)

[Andrei Borzenkov]

23.09.2018 13:07, Ian Underhill пишет:
> Im trying to design a resource layout that has different "dislikes"
> colocation scores between the various resources within the cluster.
> 
> 1) When I start to have multiple colocation dependencies from a single
> resource, strange behaviour starts to happen, in scenarios where resource
> have to bunch together
> 
> consider the example (2 node system) 3 resources
> C->B->A
> 
> constraints
> B->A -10
> C->B -INFINITY
> C->A -10
> 
> So on paper I would expect A and C to run together and B to run on its own.
> what you actually get is A and B running and C stopped?
> 
> crm_simulate -Ls says the score for C running on the same node as A is -10.
> so why doesnt it start it?
> 

Resource must have non-negative score on a node to be started on this
node. Pacemaker first selects node for A, then different node for B.
This leaves C with negative scores for both nodes.

To say anything more transaction snapshot would be helpful.