Check out http://www.datastax.com/documentation/cassandra/2.0/cassandra/dml/dml_tunable_consistency_c.html
> Cassandra 2.0 uses the Paxos consensus protocol, which resembles 2-phase commit, to support linearizable consistency. All operations are quorum-based ... This kicks in whenever you do CAS operations (eg, IF NOT EXISTS). Otherwise a cluster which became network partitioned would end up being able to have two separate CAS statements which both succeeded, but which disagreed with each other. On Sun, Jan 18, 2015 at 8:02 AM, Kevin Burton <bur...@spinn3r.com> wrote: > I’m really confused here. > > I”m calling: > > acquireInsert.setConsistencyLevel( ConsistencyLevel.ONE ); > > but I”m still getting the exception: > > com.datastax.driver.core.exceptions.UnavailableException: Not enough > replica available for query at consistency SERIAL (2 required but only 1 > alive) > > Does it matter that I’m using: > > ifNotExists(); > > and that maybe cassandra needs two because it’s using a coordinator ? > > If so then an exception should probably be thrown when I try to set a > wrong consistency level. > > which would be weird because I *do* have at least two replicas online. I > have 4 nodes in my cluster right now... > > -- > > Founder/CEO Spinn3r.com > Location: *San Francisco, CA* > blog: http://burtonator.wordpress.com > … or check out my Google+ profile > <https://plus.google.com/102718274791889610666/posts> > <http://spinn3r.com> > >
