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From Flavio Junqueira <...@yahoo-inc.com>
Subject Re: Zookeeper WAN Configuration
Date Fri, 24 Jul 2009 23:41:51 GMT
Servers in a quorum need to be able to talk to each other to elect a  
leader. Once a leader is elected, followers only talk to the leader.  
Of course, if the leader fails, servers in some quorum will need to  
talk to each other again. If no quorum can be formed, the system is  
stalled.

-Flavio

On Jul 24, 2009, at 4:37 PM, Ted Dunning wrote:

> Each member needs a connection to a quorum.  The quorum is ceiling((N 
> +1) /
> 2) members of the cluster.
>
> This guarantees that network partition does not allow two leaders to  
> go on
> stamping out revisions independent of each other.
>
> On Fri, Jul 24, 2009 at 4:23 PM, Todd Greenwood
> <toddg@audiencescience.com>wrote:
>
>> Ted, could you elaborate a bit more on this? I was under the (mis)
>> impression that each ZK server in an ensemble only needed  
>> connectivity
>> to another member in the ensemble, not to each member in the  
>> ensemble.
>> It sounds like you are saying the latter is true.
>>
>
>
>
> -- 
> Ted Dunning, CTO
> DeepDyve


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