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
|