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From Per Olesen <>
Subject Is ReplicationFactor values number of replicas or number of copies of data?
Date Mon, 07 Jun 2010 11:16:11 GMT

I am unclear about what the ReplicationFactor value means.

Does RF=1 mean that there is only one single node that has the data in the cluster (actually
no replication), or, does it mean, that there are two copies of the data - one "actual" and
one "replica" (as in "replicated one time")?

I noticed, that I CAN start a node with RF=0, but I get UnavailableException when trying to
insert, so I assume RF=0 is wrong then?

Put another way: If I want my data to always live on exactly 2 nodes in the cluster, do I
set RF=2 or RF=1? :-)

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