[Pacemaker] [pacemaker][patch 3/4] Simple changes for "Pacemaker Explained", Chapter 6 CH_Constraints.xml

[Andrew Beekhof]

On Thu, May 5, 2011 at 11:37 AM, Dejan Muhamedagic <dejanmm at fastmail.fm> wrote:
> On Thu, May 05, 2011 at 09:07:05AM +0200, Andrew Beekhof wrote:
>> On Wed, May 4, 2011 at 7:15 PM, Dejan Muhamedagic <dejanmm at fastmail.fm> wrote:
>> > Hi,
>> >
>> > On Wed, May 04, 2011 at 12:49:03PM +0200, Andrew Beekhof wrote:
>> >> Tick tock.  I'm going to push this soon unless someone raises an objection RSN.
>> >>
>> >> On Fri, Apr 15, 2011 at 4:55 PM, Andrew Beekhof <andrew at beekhof.net> wrote:
>> >> > On Fri, Apr 15, 2011 at 3:00 PM, Lars Marowsky-Bree <lmb at novell.com> wrote:
>> >> >> On 2011-04-13T08:37:12, Andrew Beekhof <andrew at beekhof.net> wrote:
>> >> >>
>> >> >>> >> Before:
>> >> >>> >>
>> >> >>> >>       <rsc_colocation id="coloc-set" score="INFINITY">
>> >> >>> >>         <resource_set id="coloc-set-0">
>> >> >>> >>           <resource_ref id="dummy2"/>
>> >> >>> >>           <resource_ref id="dummy3"/>
>> >> >>> >>         </resource_set>
>> >> >>> >>         <resource_set id="coloc-set-1" sequential="false" role="Master">
>> >> >>> >>           <resource_ref id="dummy0"/>
>> >> >>> >>           <resource_ref id="dummy1"/>
>> >> >>> >>         </resource_set>
>> >> >>> >>       </rsc_colocation>
>> >> >>> >>       <rsc_order id="order-set" score="INFINITY">
>> >> >>> >>         <resource_set id="order-set-0" role="Master">
>> >> >>> >>           <resource_ref id="dummy0"/>
>> >> >>> >>           <resource_ref id="dummy1"/>
>> >> >>> >>         </resource_set>
>> >> >>> >>         <resource_set id="order-set-1" sequential="false">
>> >> >>> >>           <resource_ref id="dummy2"/>
>> >> >>> >>           <resource_ref id="dummy3"/>
>> >> >>> >>         </resource_set>
>> >> >>> >>       </rsc_order>
>> >> >>> >>
>> >> >>> >>
>> >> >>> >>
>> >> >>> >> After:
>> >> >>
>> >> >> So I am understanding this properly - we're getting rid of the
>> >> >> "sequential" attribute, yes?
>> >> >
>> >> > Absolutely.
>> >
>> > So, the internal-collocation replaces the sequential attribute?
>>
>> Yes.
>>
>> > What are the possible and/or meaningfull values for
>> > internal-collocation? It looks like that would be 0 or INFINITY
>> > only, which would translate to old sequential false and true,
>> > right?
>>
>> No.
>>
>>               <choice>
>>                 <data type="integer"/>
>>                 <value>INFINITY</value>
>>                 <value>+INFINITY</value>
>>                 <value>-INFINITY</value>
>>               </choice>
>
> I saw that, but wonder what makes sense in this context. What's
> the difference between values 0, INF, 50, -50, 100? Are all those
> necessary?

Just as necessary as for colocation constraints not involving sets.
You're setting up the colocation score between elements of the set.

>
>> > Looking at the schema, the ordering constraint lost score
>>
>> Score was being mapped to "kind" inside the PE anyway.
>>
>> > and is
>> > using only the kind attribute which can have one of:
>> >
>> >      <value>None</value>
>> >      <value>Optional</value>
>> >      <value>Mandatory</value>
>> >      <value>Serialize</value>
>> >
>> > But then, the "kind" attribute is optional. If missing, how's
>> > that different from value None?
>>
>> If its missing you get the default.  Which IIRC is Mandatory not None.
>>
>> > What does Serialize mean? (in orders)
>>
>> Same as it did before, this is not new.
>>
>> > What does score-attribute-mangle mean? (in collocations)
>>
>> As above.  Not new.
>
> Where are these two documented? Couldn't find anything in the
> docs.

Looks to be just an alias for XML_RULE_ATTR_SCORE_ATTRIBUTE dating back to 2005.
So there is probably a reason I didn't document it.

Serialize is newer.  Its like optional but for a set - no member will
start or stop at the same time as another.

>
>> > It's good that finally the role/action got next to the resource.
>>
>> Agreed.
>>
>> > I think that it'd be good to clarify the shell syntax before
>> > applying these changes.
>>
>> Yes, but I'm not going to wait forever.
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>
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