[Linux-HA] Handling colocation constraints with more than 2 entries

RaSca rasca at miamammausalinux.org
Wed Oct 6 04:50:03 MDT 2010


Il giorno Mer 06 Ott 2010 12:34:22 CET, Dejan Muhamedagic ha scritto:
[...]
> There's also role change which forces a break in the set. There
> was posted an example like this to the list:
> (a) collocation c1 inf: ms-r0:Master fs jboss
> or, expressed as a chain of two-resource collocations:
> collocation c1_1 inf: jboss fs
> collocation c1_2 inf: fs ms-r0:Master
> Now, the resource set would have to be split in two because of
> the role change, but that would also force us to move stuff
> around to preserve semantics:
> (b) collocation c1 inf: [ fs jboss ] [ ms-r0:Master ]
> Because adjacent resource sets have the same semantics as
> two-resource collocations, right?
> The case when the role change is in the middle:
> (a) collocation c1 inf: A B:Master C
> becomes
> (b) collocation c1 inf: [ C ] [ B:Master ] [ A ]
> All this strikes me as suboptimal, but I'm not sure what is to be
> done about it.
> Basically, users should be able to type the (a) versions and let
> the software handle the rest.
> Opinions?
> Cheers,
> Dejan

I totally agree with you Dej. Note that for making things work and keep 
things compatible an automated management of the sets like this one is 
IMHO the best way.

Glad to see that my problems created such a discussion!

-- 
RaSca
Mia Mamma Usa Linux: Niente è impossibile da capire, se lo spieghi bene!
rasca at miamammausalinux.org
http://www.miamammausalinux.org



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