On Thu, Apr 8, 2010 at 7:16 AM, Gary Dusbabek <gdusba...@gmail.com> wrote: > On Thu, Apr 8, 2010 at 02:55, Paul Prescod <p...@ayogo.com> wrote: >> In this¹ debate, there seemed to be consensus on the following fact: >> >> "In Cassandra, say you use N=3, W=3 & R=1. Let’s say you managed to >> only write to replicas A & B, but not C. In this case Cassandra will >> return an error to the application saying the write failed- which is >> acceptable given than W=3. But Cassandra does not cleanup/rollback the >> writes that happened to A & B." >> > > correct: no rolling back. Cassandra does go out of its way to make > sure the cluster is healthy enough to begin the write though.
I think the general answer here is don't use R=1 if you can't tolerate inconsistency? Still the point of confusion -- if W=3 and the write succeeds on 2 nodes but fails the 3rd, the write fails (to the updating client), but is the data on the two successful nodes still readable (i.e. reading from what was actually a failed write)?
