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From Pinak Pani <nishant.has.a.quest...@gmail.com>
Subject Re: In a multiple data center setup, do all the data centers have complete data irrespective of RF?
Date Mon, 20 May 2013 17:01:30 GMT
Assume NetworkTopologyStrategy. So, I wanted to know whether a data-center
will contain all the keys?

This is the case:

CREATE KEYSPACE appKS
  WITH placement_strategy = 'NetworkTopologyStrategy'
  AND strategy_options={DC1:3, DC2:3};

Does DC1 and DC2 each contain complete database corpus? That is, if DC1
blows, will I get all the data from DC2? Assume RF = 1.

Sorry, for the very elementary question. This is the post that made me ask
this question:
http://www.onsip.com/blog/2011/07/15/intro-to-cassandra-and-networktopologystrategy

It says,

"NTS creates an iterator for EACH datacenter and places writes discretely
for each. The result is that NTS basically breaks each datacenter into it's
own logical ring when it places writes."

That seems to mean that each data-center behaves as an independent ring
with initial_token. So, If I have 2 data centers and NTS, I am basically
mirroring the database. Right?

Thanks,
PP

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