In your options, you have configured 2 replicas for each data center: Options: [DC2:2, DC1:2]
If one of those replicas is down, then LOCAL_QUORUM will fail as there is only one replica left 'locally.' On Fri, Sep 2, 2011 at 3:35 PM, Oleg Tsvinev <oleg.tsvi...@gmail.com> wrote: > from http://www.datastax.com/docs/0.8/consistency/index: > > <A “quorum” of replicas is essentially a majority of replicas, or RF / > 2 + 1 with any resulting fractions rounded down.> > > I have RF=2, so majority of replicas is 2/2+1=2 which I have after 3rd > node goes down? > > On Fri, Sep 2, 2011 at 1:22 PM, Nate McCall <n...@datastax.com> wrote: >> It looks like you only have 2 replicas configured in each data center? >> >> If so, LOCAL_QUORUM cannot be achieved with a host down same as with >> QUORUM on RF=2 in a single DC cluster. >> >> On Fri, Sep 2, 2011 at 1:40 PM, Oleg Tsvinev <oleg.tsvi...@gmail.com> wrote: >>> I believe I don't quite understand semantics of this exception: >>> >>> me.prettyprint.hector.api.exceptions.HUnavailableException: : May not >>> be enough replicas present to handle consistency level. >>> >>> Does it mean there *might be* enough? >>> Does it mean there *is not* enough? >>> >>> My case is as following - I have 3 nodes with keyspaces configured as >>> following: >>> >>> Replication Strategy: org.apache.cassandra.locator.NetworkTopologyStrategy >>> Durable Writes: true >>> Options: [DC2:2, DC1:2] >>> >>> Hector can only connect to nodes in DC1 and configured to neither see >>> nor connect to nodes in DC2. This is for replication by Cassandra >>> means, asynchronously between datacenters DC1 and DC2. Each of 6 total >>> nodes can see any of the remaining 5. >>> >>> and inserts with LOCAL_QUORUM CL work fine when all 3 nodes are up. >>> However, this morning one node went down and I started seeing the >>> HUnavailableException: : May not be enough replicas present to handle >>> consistency level. >>> >>> I believed if I have 3 nodes and one goes down, two remaining nodes >>> are sufficient for my configuration. >>> >>> Please help me to understand what's going on. >>> >> >
