[ClusterLabs] Why do clusters have a name?

[Jehan-Guillaume de Rorthais]

On Wed, 27 Mar 2019 10:20:21 +0100
Kristoffer Grönlund <kristoffer.gronlund at suse.com> wrote:

> 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

distinct cluster of Pacemaker/corosync daemons on the same servers or distinct
cluster of servers?

> and sharing the same configuration across all of
> them,

Same configuration like, the same file or the same content accross different
files?

Sorry for being bold...I just don't get it :/