cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jonathan Ellis <>
Subject Re: Scaling from 1 to x (was: one server or more servers?)
Date Fri, 17 Jul 2009 20:36:56 GMT
HH is a mechanism to reduce inconsistency, but a node holding a HH row
while waiting for the "right" node to recover won't be part of the
group that is queried for it (since it could be anywhere).  So if you
set block_for to M and less than M of the actual replica destinations
are up, Cassandra will fail the write.

If you set block_for to zero, then writes will indeed never fail
(unless the node the client is talking to dies mid-action, of course).


On Fri, Jul 17, 2009 at 3:01 PM, Vijay<> wrote:
> "since the write will fail if one of the target nodes is down"
> I thought Hinted handoff will take care of this Right? Write will never fail
> insted it will write to another node right?
> correct me if i am wrong.
> Thanks and Regards,
> </VJ>
> On Tue, Jul 14, 2009 at 7:26 AM, Jonathan Ellis <> wrote:
>> N: guarantees consistent reads without having to wait for a quorum, so
>> you trade write latency and availability (since the write will fail if
>> one of the target nodes is down) for 100% consistency and reduced read
>> latency

View raw message