[ClusterLabs] Why do clusters have a name?

[Kristoffer Grönlund]

On Wed, 2019-03-27 at 10:13 +0100, Jehan-Guillaume de Rorthais wrote:
> On Wed, 27 Mar 2019 09:59:16 +0100
> Kristoffer Grönlund <kristoffer.gronlund at suse.com> wrote:
> 
> > On Wed, 2019-03-27 at 08:27 +0100, Ivan Devát  wrote:
> > > On 26. 03. 19 21:12, Brian Reichert wrote:  
> > > > This will sound like a dumb question:
> > > > 
> > > > The manpage for pcs(8) implies that to set up a cluster, one
> > > > needs
> > > > to provide a name.
> > > > 
> > > > Why do clusters have names?
> > > > 
> > > > Is there a use case wherein there would be multiple clusters
> > > > visible
> > > > in an administrative UI, such that they'd need to be
> > > > differentiated?
> > > >   
> > > 
> > > For example in a web UI of pcs is a page with multiple clusters.
> > >   
> > 
> > We use cluster names and rules to apply the same exact CIB to
> > multiple
> > clusters, particularly when configuring geo clusters.
> 
> I'm not sure to understand. Is it possible to have multiple Pacemaker
> daemon instances on the same serveurs?
> 
> Or do you mean it is possible to have multiple namespace where
> resources are
> isolated in and one Pacemaker daemon to manage them?
> 

I am not sure what you mean by the second, but I am fairly sure I don't
mean either of those :) I'm talking about having multiple actual,
distinct clusters and sharing the same configuration across all of
them, using rules to separate the cases where the configurations
differ.

Cheers,
Kristoffer