Hello Shawn. Thank you very much for the comment.
On 24 June 2017 at 16:14, Shawn Heisey <apa...@elyograg.org> wrote: > On 6/24/2017 2:14 AM, Arcadius Ahouansou wrote: > > Interpretation 1: > > ZooKeeper doesn't *need* an odd number of servers, but there's no > benefit to an even number. If you have 5 servers, two can go down. If > you have 6 servers, you can still only lose two, so you might as well > just run 5. You'd have fewer possible points of failure, less power > usage, and less bandwidth usage. > > About Slide 8 and the odd/even number of nodes... what I meant is that on Slide 8, if you loose DC1, then your cluster will not be able to recover after DC1 comes back as there will be no clear majority and you will have: - 3 ZK nodes with up-to-date data (that is DC2+DC3) and - 3 ZK nodes with out-of-date data (DC1). But, if you had only 2 ZK nodes in DC1, then you could afford to loose one of either DC1, or DC2 or DC3 and the cluster will be able to recover and be OK Thank you very much. Arcadius -- Arcadius Ahouansou Menelic Ltd | Applied Knowledge Is Power Office : +441444702101 Mobile: +447908761999 Web: www.menelic.com ---
