On Thu, Apr 3, 2014 at 8:38 AM, Alain RODRIGUEZ <arodrime@gmail.com> wrote:
I read that we can use different A-Z to be more "crash tolerant". Basically, using a RF=3 and placing servers into different zones like node1-zoneA node2-zoneB node3-zoneC node4-zoneA... As replicas are placed to the next server in the ring we can manage to have a replica in each zone and for each replica. So all the data is present in the 3 zones (A, B and C).

Is there a way to achieve this exact same result using vnodes ? Would it be possible, using EC2Snitch (or EC2MultiRegionSnitch) and vnodes, to make sure to spread replicas among available A-Z automatically ?

https://issues.apache.org/jira/browse/CASSANDRA-4658
https://issues.apache.org/jira/browse/CASSANDRA-4123

And especially...

https://issues.apache.org/jira/browse/CASSANDRA-3810

tl;dr - status quo NTS is probably fine and does more or less what you need it to do, caveated by 3810. But in theory far future versions of cassandra might have slightly improved functionality.

=Rob