On Fri, Jul 3, 2009 at 7:14 PM, Evan Weaver <eweaver@gmail.com> wrote:
You can (once the API is fixed) make a client request the data from
every replica on read.  Which ever replica has the most recent value
will be the value that's returned. That makes sure that reads and
writes are consistently serialized from the server's perspective, at
some performance cost.

Weak reads request from one node. Strong reads let you tune the number
of nodes to check from 1 up to the replica count.

Cassandra, though, is not transactional. You need some kind of lock
server to guarantee that there aren't read/modify/write races from the
client's perspective. Zookeeper would probably work.

Thanks Evan, that makes sense.