[ClusterLabs] Reusing resource set in multiple constraints

[Andrei Borzenkov]

27.07.2019 11:04, Andrei Borzenkov пишет:
> Is it possible to have single definition of resource set that is later
> references in order and location constraints? All syntax in
> documentation or crmsh presumes inline set definition in location or
> order statement.
> 
> In this particular case there will be set of filesystems that need to be
> colocated and ordered against other resources; these filesystems will be
> extended over time and I would like to add new definition in just one place.
> 

I tried to play with id-refs, but it is not really usable.

1. It is impossible to define "standalone" resource set - set definition
is accepted only as part of constraint definition.

2. It is impossible to change set attributes (like sequential) when
using id-ref. Because attributes in order and colocation constraints
have different semantic, it is quite possible that for the same set of
resources different "sequential" value is needed in both.

3. crmsh does not support id-refs at all. It neither allows defining set
id (it auto-generates names), nor understand id-ref at all. Because
auto-generated names are position dependent, any change in configured
sets would invalidate any reference to them.

Need to make changes in several places obviously does not facilitate
fool proof management (or requires building some additional layer on top).