[Pacemaker] Enable remote monitoring

[Lars Marowsky-Bree]

On 2012-12-03T16:32:14, David Vossel <dvossel at redhat.com> wrote:

> > +      <optional>
> > +	<attribute name="restart-origin"><data type="boolean"/></attribute>
> > +      </optional>
> 
> I don't feel strongly about this. Here's what comes to mind for me.
> 
> force-recover - force recovery of both sides of the constraint if either side fails

We actually have a precedent here - grep for restart_type. ;-)

"force-recover" doesn't quite fit for me; because for the first->then
distinction, we already have the 0 versus inf score differentiation.
What would force-recover do for score=0?

(Ohhh. Did we just find a use for a negative score here? ;-) Just
throwing that out there. It'd fit the model we have so far, is all I'm
saying.)

But - I think restarting alone doesn't suffice. Do we want to have the
restarts count towards the migration-threshold of the parent resource
too? I think we may want that.

If we want to stick with the terminology, "restart-first" (but -origin
sounds better, so I don't feel that strongly either) as a tri-state (no
(default), yes, treat-as-failure (anyone got a snappy idea for that
one?) might make be advisable.


> Here's a thought.  Add the new constraint flag as well as a new option on the primitive that escalates failures to the parent resource (pretty sure this idea isn't mine, maybe Andrew threw it at me a few weeks ago)
> 
> Then you could do something like this.
> 
> primitive vm
> group vm-resources
>     primitive nagios-monitor-foo
>     primitive nagios-monitor-bar
> 
> order vm then vm-resources reset-origin
> colocation vm vm-resources.
> 
> 
> It isn't as simple (configuration wise, not implementation wise) as the container concept, but at least this way you don't have to build relationships between the vm and every resource in it explicitly.  It seems like leveraging groups here would be a good idea.

One the one hand, this makes a lot of sense.

But when we're going this far, why not directly:

group vm-with-resources vm nagios-monitor-foo nagios-monitor-bar \
	meta restart-origin="true"

? All we'd be doing is flip the restart-origin bit on the orders
implicit in the group.


Regards,
    Lars

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