On Mon, Jan 17, 2011 at 2:10 PM, Samuel Benz <samuel.b...@switch.ch> wrote: >>> Case1: >>> If 'TEST' was previous stored on Node1, Node2, Node3 -> The update will >>> succeed. >>> >>> Case2: >>> If 'TEST' was previous stored on Node2, Node3, Node4 -> The update will >>> not work. >> >> If you have RF=2 then it will be stored on 2 nodes, not 3. I think >> this is the source of the confusion. >> > > I checked the existence of the row on the different serverver with > sstablekeys after flushing. So I saw three copies of every key in the > cluster.
If you want to be guaranteed to be able to read with two nodes down and RF=3, you have to read at CL.ONE, since if the two nodes that are down are replicas of the data you are reading (as in the 2nd case here) Cassandra will be unable to achieve quorum (quorum of 3 is 2 live nodes). -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of Riptano, the source for professional Cassandra support http://riptano.com
