To me, CL.TWO and CL.THREE are more like work around of the problem, for example, they do not work if the number of replicas go to 8, which does possible in our environment (2 replicas in each of 4 DCs).
What people want from quorum is strong consistency guarantee, as long as R+W > N, there are three options: a) R=W=(n/2+1); b) R=(n/2), W=(n/2+1); c) R=(n/2+1), W=(n/2). What Cassandra doing right now, is the option a), which is the most expensive option. I can not think of a reason, that people want the quorum read, not for strong consistency reason, but just to read from (n/2+1) nodes. If they want strong consistency, then the read just needs (n/2) nodes, we are purely waste the one extra request, and hurts read latency as well. Thanks Dikang. On Thu, Jun 8, 2017 at 8:20 PM, Nate McCall <n...@thelastpickle.com> wrote: > > We have CL.TWO. >> >> >> > This was actually the original motivation for CL.TWO and CL.THREE if > memory serves: > https://issues.apache.org/jira/browse/CASSANDRA-2013 > -- Dikang
