[Pacemaker] RFC: cluster-wide attributes

[Lars Marowsky-Bree]

Hi,

another idea that goes along with the previous post are cluster-wide
attributes. Similar to per-node attributes, but basically a special
section in <configuration>:

	<optional>
        <element name="cluster_attributes">
          <zeroOrMore>
            <element name="attributes">
              <externalRef href="nvset.rng"/>
            </element>
          </zeroOrMore>
        </element>
	</optional>

These then would also be referencable in the various dependencies like
node attributes, just globally.

Question -

1. Do we want to treat them like true node attributes, i.e., per-node
attributes would override the cluster-wide settings - or as indeed a
completely separate class? I lean towards the latter, but would solicit
some more opinions.

2. Is this a collocation or an order constraint? It comes out
approximately the same - if the attribute isn't present, the resource
can't be collocated with the cluster; and so it has to be acquired first
(implying ordering). I'm not sure we want to indeed make this accessible
for all constraint types; maybe best to pick one?


Regards,
    Lars

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