[Pacemaker] Andrew and Lars please confirm this.

[Romi Verma]

Thanks Andrew,



>
> Pacemaker has various options for how it behaves during a split-brain, but
> 1) Its more desirable to avoid them in the first place
> 2) None of the strategies are (yet) really suited to failing over from
> one physical location to another


i could not understand the second point.  i am new to openais-pacemaker ,
but as far as i know we have lots of stoniths . for example if we have
configured ilo properly then we can use riloe stonith and fence the node
residing in other partiton. what is stopping us and why we are saying that
we dont support cluster whose nodes spans over multiple site?? could you
please explain it bit more.

and when u say "None of the strategies are (yet) really suited to failing
over from
one physical location to another"
does it apply to nodes who sapns over adjancent rooms also.??

sorry for bugging you too much.
Thanks a lot again for clearing my concepts.


>
> >> That's why it is
> >> recommend to have a local cluster  ( nodes sharing same rack).
> >>
> >> am i right??
> >>
> >> Thanks & Regards,
> >>
> >> On Mon, Mar 2, 2009 at 12:47 PM, Andrew Beekhof <beekhof at gmail.com>
> wrote:
> >>>
> >>> On Mon, Mar 2, 2009 at 04:27, Romi Verma <romi3rdfeb at gmail.com> wrote:
> >>> > Thanks Andrew and Lars,
> >>> > I would like  to understand it bit more. , is there any distance
> >>> > parameter
> >>> > here? i mean to say suppose i have two nodes in one room and 1 node
> in
> >>> > adjacent room  , cant i form three nodes openais/pacemaker cluster
> >>> > here.
> >>>
> >>> of course.
> >>> i believe the point is that as the distance increases, so does the
> >>> number of switches/telcos involved and therefor the probability of a
> >>> comms failure is between the two sites is quite high.
> >>> as is the latency...
> >>>
> >>> >  i was under impression that as far as multicast ip works , nothing
> >>> > stops us
> >>> > in forming a cluster.
> >>> >
> >>> > Regrards,
> >>> >
> >>> >
> >>> > On Sat, Feb 28, 2009 at 12:04 AM, Lars Marowsky-Bree <lmb at suse.de>
> >>> > wrote:
> >>> >>
> >>> >> On 2009-02-27T13:38:02, Romi Verma <romi3rdfeb at gmail.com> wrote:
> >>> >>
> >>> >> > Thanks for reply Andrew,
> >>> >> > ok, then how openais-pacemaker cluster handles the cluster whose
> >>> >> > nodes
> >>> >> > span
> >>> >> > across multiple sites.
> >>> >>
> >>> >> This is not currently handled.
> >>> >>
> >>> >> But deploying a split-site setup with quorumd never worked either;
> it
> >>> >> is
> >>> >> not integrated with fencing, and it is impossible to build a working
> >>> >> split-site cluster with it. This was, I'm afraid to say, only a 40%
> >>> >> implementation of the solution even in heartbeat/CCM land.
> >>> >>
> >>> >>
> >>> >> Having proper split-site support is on the roadmap, as soon as the
> >>> >> openAIS integration stabilizes.
> >>> >>
> >>> >>
> >>> >> Regards,
> >>> >>    Lars
> >>> >>
> >>> >> --
> >>> >> Teamlead Kernel, SuSE Labs, Research and Development
> >>> >> SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nürnberg)
> >>> >> "Experience is the name everyone gives to their mistakes." -- Oscar
> >>> >> Wilde
> >>> >>
> >>> >>
> >>> >> _______________________________________________
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> >>> >> http://oss.clusterlabs.org/mailman/listinfo/pacemaker
> >>> >
> >>> >
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> >
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