[Pacemaker] RFC: cluster-wide attributes

[Tim Serong]

On 7/5/2010 at 04:54 PM, Andrew Beekhof <andrew at beekhof.net> wrote: 
> On Mon, Jul 5, 2010 at 6:21 AM, Tim Serong <tserong at novell.com> wrote: 
> > On 6/30/2010 at 09:42 PM, Andrew Beekhof <andrew at beekhof.net> wrote: 
> >> On Thu, Jun 24, 2010 at 5:41 PM, Lars Marowsky-Bree <lmb at novell.com> wrote: 
> >> > 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> 
> >> 
> >> Do we need a new section? Or can they go in with cluster-infrastructure etc? 
> >> 
> >> > 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. 
> >> 
> >> Not sure it really gives you anything by making them a separate class. does 
> >> it? 
> >> Just means you have to look twice right? 
> > 
> > Just for the record, a use case of this came up on IRC last week: 
> > you could specify cluster-wide standby="on", so new nodes joining the 
> > cluster would automatically join in standby mode, with the admin 
> > activating them later (per-node standby="off" thus overriding cluster- 
> > wide attribute). 
>  
> That doesn't necessarily mean they need to be a separate class though. 

No, not at all.  I'm just adding to the conversation in an unnecessarily
confusing fashion :)

Tim


-- 
Tim Serong <tserong at novell.com>
Senior Clustering Engineer, OPS Engineering, Novell Inc.