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From Gianny Damour <gianny.dam...@optusnet.com.au>
Subject Re: gcache implementation ideas[long]
Date Thu, 14 Sep 2006 13:30:05 GMT

On 14/09/2006, at 10:58 PM, Jacek Laskowski wrote:

> On 9/14/06, Jeff Genender <jgenender@apache.org> wrote:
>> David Jencks wrote:
>
>> > - slave 1 (or any intermediate slave) goes down.
>> > - slave 1 (or any intermediate slave) comes back up
>> > - slave n (last slave) goes down.
>>
>> All great questions.  I would like feedback here.
>
> See above. The next slave will act as a master until all are gone and
> the cluster is deemed to have failed. The way 'the next' is computed
> depends on the magical strategy that's in use (it could be the next in
> the sense of a list concept or computed randomly).
I agree. I think that the way this could be achieved is by the mean  
of an  ActiveCluster or WADI like API. Basically, each node executes  
locally an election strategy, when a failure is detected. If the  
election strategy implementation has a determistic outcome, i.e. each  
node uses the same list of nodes and each of them elects the same  
one, then you have your next master. For instance, the WADI  
implementation is to use the oldest node of the cluster.

I think that if each node picks a node at random, then each one will  
have to broadcast their selection to the other nodes. I believe that  
if one of them has quorum, then each node does know now which of them  
is master.

Thanks,
Gianny


>
> Jacek
>
> -- 
> Jacek Laskowski
> http://www.laskowski.net.pl


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