On 6/17/2011 1:27 PM, Sasha Dolgy wrote:
Replication factor is defined per keyspace if i'm not mistaken. Can't
remember if NTS is per keyspace or per cluster ... if it's per
keyspace, that would be a way around it ... without having to maintain
multiple clusters .... just have multiple keyspaces ...
Hey! I think you're on to something Sasha! Placement strat and RF are
both defined per ks. I'll let that stew for a while in my brain.
Thanks!
On Fri, Jun 17, 2011 at 9:23 PM, AJ<a...@dude.podzone.net> wrote:
On 6/17/2011 12:32 PM, Jeremiah Jordan wrote:
Run two clusters, one which has {DC1:2, DC2:1} and one which is
{DC1:1,DC2:2}. You can't have both in the same cluster, otherwise it
isn't possible to tell where the data got written when you want to read
it. For a given key "XYZ" you must be able to compute which nodes it is
stored on just using "XYZ", so a strategy where it is on nodes
DC1_1,DC1_2, and DC2_1 when a node in DC1 is the coordinator, and to
DC1_1, DC2_1 and DC2_2 when a node in DC2 is the coordinator won't work.
Given just "XYZ" I don't know where to look for the data.
But, from the way you describe what you want to happen, clients
from DC1 aren't using data inserted by clients from DC2, so you should
just make two different Cassandra clusters. Once for the DC1 guys which
is {DC1:2, DC2:1} and one for the DC2 guys which is {DC1:1,DC2:2}.
Interesting. Thx.
