[Pacemaker] Shouldn't colocation -inf: be mandatory?

[Dejan Muhamedagic]

On Tue, Jun 15, 2010 at 03:41:17PM -0400, Vadym Chepkov wrote:
> 
> On Jun 15, 2010, at 3:36 PM, Dejan Muhamedagic wrote:
> 
> > Hi,
> > 
> > On Tue, Jun 15, 2010 at 08:45:37AM -0400, Vadym Chepkov wrote:
> >> 
> >> On Jun 15, 2010, at 6:14 AM, Dejan Muhamedagic wrote:
> >> 
> >>> Hi,
> >>> 
> >>> On Tue, Jun 15, 2010 at 10:57:47AM +0200, Andrew Beekhof wrote:
> >>>> On Tue, Jun 15, 2010 at 10:23 AM, Andreas Kurz <andreas.kurz at linbit.com> wrote:
> >>>>> On Tuesday 15 June 2010 08:40:58 Andrew Beekhof wrote:
> >>>>>> On Mon, Jun 14, 2010 at 4:22 PM, Vadym Chepkov <vchepkov at gmail.com> wrote:
> >>>>>>> On Jun 7, 2010, at 8:04 AM, Vadym Chepkov wrote:
> >>>>>>>> I filed bug 2435, glad to hear "it's not me"
> >>>>>>> 
> >>>>>>> Andrew closed this bug
> >>>>>>> (http://developerbugs.linux-foundation.org/show_bug.cgi?id=2435) as
> >>>>>>> resolved, but I respectfully disagree.
> >>>>>>> 
> >>>>>>> I will try to explain a problem again in this list.
> >>>>>>> 
> >>>>>>> lets assume you want to have several resources running on the same node.
> >>>>>>> They are independent, so if one is going down, others shouldn't be
> >>>>>>> stopped. You would do this by using a resource set, like this:
> >>>>>>> 
> >>>>>>> primitive dummy1 ocf:pacemaker:Dummy
> >>>>>>> primitive dummy2 ocf:pacemaker:Dummy
> >>>>>>> primitive dummy3 ocf:pacemaker:Dummy
> >>>>>>> colocation together inf: ( dummy1 dummy2 dummy3 )
> >>>>>>> 
> >>>>>>> and I expect them to run on the same host, but they are not and I
> >>>>>>> attached hb_report to the case to prove it.
> >>>>>>> 
> >>>>>>> Andrew closed it with the comment "Thats because you have
> >>>>>>> sequential="false" for the colocation set." But sequential="false" means
> >>>>>>> doesn't matter what order do they start.
> >>>>>> 
> >>>>>> No.  Thats not what it means.
> >>>>>> And I believe I should know.
> >>>>>> 
> >>>>>> It means that the members of the set are NOT collocated with each
> >>>>>> other, only with any preceding set.
> >>>>> 
> >>>>> Just for clarification:
> >>>>> 
> >>>>> colocation together inf: ( dummy1 dummy2 dummy3 ) dummy4
> >>>>> 
> >>>>> .... is a shortcut for:
> >>>>> 
> >>>>> colocation together1 inf: dummy4 dummy1
> >>>>> colocation together1 inf: dummy4 dummy2
> >>>>> colocation together1 inf: dummy4 dummy3
> >>>>> 
> >>>>> ... is that correct?
> >>>> 
> >>>> Only if sequential != false.
> >>> 
> >>> You wanted to say "sequential == false"?
> >>> 
> >>>> For some reason the shell appears to be setting that by default.
> >>> 
> >>> This is sequential == false:
> >>> 
> >>> colocation together inf: ( dummy1 dummy2 dummy3 ) dummy4
> >>> 
> >>> This is sequential == true:
> >>> 
> >>> colocation together inf: dummy1 dummy2 dummy3 dummy4
> >>> 
> >>> Thanks,
> >>> 
> >>> Dejan
> >> 
> >> 
> >> I guess colocation syntax needs to be expanded to allow something like this
> >> 
> >> colocation only-one -inf: (dummy1 dummy2 sequential="true")
> >> 
> >> colocation together 5000: (dummy1 dummy2 sequential="true")
> > 
> > How's this different from a regular constraint?
> > 
> 
> 
> Because it does not create a resource set with two resources
> and if you put it in parentheses, it creates set with sequential="false"

What I meant was what is the difference between these two:

<rsc_colocation id="c1" rsc="p1" score="500" with-rsc="p2"/>

<rsc_colocation id="c1" score="500">
<resource_set id="c1-0">
  <resource_ref id="p1"/>
  <resource_ref id="p2"/>
</resource_set>
</rsc_colocation>

Thanks,

Dejan

> Vadym
>  
> 
> 
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