[Pacemaker] spilit brain situation

[Andrew Beekhof]

On Feb 6, 2009, at 9:53 AM, Romi Verma wrote:

> Thanks Dominic,
> i have two questions now.
>
> 1) what does no-quorum-policy= suicide means then??  does it remove  
> the resource completely.

no, the node kills itself and any other node in the partition
this makes no sense in a 2 node cluster because both nodes will do this

>
>
> 2) why each node is thinking itsef as DC as Andrew said after spilit  
> brain election happens and one node is selected as DC.

no, i said after the split-brain is _repaired_ an election occurs.
clearly this can't happen during a split-brian because by definition  
they can't communicate.

> This is not happening in my case.
> i dont have any stonith configured in my cluster . do i need stonith  
> to handle spilit brain situation.
>
>
>
> On Fri, Feb 6, 2009 at 1:59 PM, Dominik Klein <dk at in-telegence.net>  
> wrote:
> Romi Verma wrote:
> > Thanks for fast reply ,
> > Ok, Let me explain the situation. i have two nodes cluster . i  
> pulled out
> > the network cable of one
> > node which produced spilit brain situation. this time both nodes are
> > thinking that other one is dead.  each node is thinking itself as  
> DC and on
> > each node cluster is up and running without quorum.
> >
> > i am new to openais/pacemaker so dont know much but according to  
> some
> > documents it seems by default no-quorum-policy is  to "stop" the  
> cluster. i
> > have not specified any no-quorum-policy that's why i expect that  
> my cluster
> > should stop if it looses quorum somehow.
>
> The "stop" refers to the resources. policy=stop on a node with no  
> quorum
> means: do not run any resources.
>
> "ignore" would mean: run resources even though we don't have quorum
> (like the old heartbeat behaviour would be)
>
> "freeze" would mean: run and manage what you did run up to this point,
> but don't aquire any other resources.
>
> Regards
> Dominik
>
> > But in present spilit brain situation , on each node cluster is up  
> and
> > running without quorum.   could you please explain why this is  
> happening.
> >
> > Romi
> >
> >
> > On Fri, Feb 6, 2009 at 12:52 PM, Andrew Beekhof  
> <beekhof at gmail.com> wrote:
> >
> >> Well the no-quorum-policy option applies during the split and an  
> election
> >> is held to determine the DC when the partitions reform.
> >> Can you be more specific please?
> >> On Feb 6, 2009, at 4:54 AM, Romi Verma wrote:
> >>
> >>
> >>
> >> hi all,
> >>> how does openais + pacemaker (suse 11) cluster handles spilit  
> brain
> >>> situation .  can any one explain.
> >>>
> >>> Thanks,
> >>> Romi.
> >>>
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