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From Kaushal Shriyan <kaushalshri...@gmail.com>
Subject Meaning of quorum and ensemble
Date Fri, 29 May 2015 17:08:01 GMT
Hi,

I have a question regarding quorum in context to
http://stackoverflow.com/questions/13022244/zookeeper-reliability-three-versus-five-nodes

Zookeeper requires that you have a quorum of servers up, where quorum is
ceil(N/2). For a 3 server ensemble, that means 2 servers must be up at any
time, for a 5 server ensemble, 3 servers need to be up at any time.

   1. what does quorum mean?
   2. so does ceil(N/2) mean 3+1/2 = 4/2 which is 2 servers in context to 3
   server ensemble and 5+1/2 = 6/2 which is 3 servers in context to 5 server
   ensemble if the ceil(N/2) is a ceiling function?
   3. what does ensemble mean in context to Apache zookeeper?

I would appreciate your help.

Regards,

Kaushal

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