For that matter, RF=1 and QUORUM are incompatible (if you want to be able to
take a node down).
In other words, if you use QUORUM, you need RF>=3.
On Sun, Nov 28, 2010 at 8:04 PM, Jake Luciani wrote:
> Right.
>
>
> On Sun, Nov 28, 2010 at 1:03 PM, David Boxenhorn wrote:
>
>> OK. To sum up: RF=2
Put another way, "for RF=2, QUORUM is equivalent to ALL."
On Sun, Nov 28, 2010 at 12:03 PM, David Boxenhorn wrote:
> OK. To sum up: RF=2 and QUORUM are incompatible (if you want to be able to
> take a node down).
>
> Right?
--
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano
Right.
On Sun, Nov 28, 2010 at 1:03 PM, David Boxenhorn wrote:
> OK. To sum up: RF=2 and QUORUM are incompatible (if you want to be able to
> take a node down).
>
> Right?
>
> On Sun, Nov 28, 2010 at 7:59 PM, Jake Luciani wrote:
>
>> I was wrong on this scenario and I'll explain where I was inc
OK. To sum up: RF=2 and QUORUM are incompatible (if you want to be able to
take a node down).
Right?
On Sun, Nov 28, 2010 at 7:59 PM, Jake Luciani wrote:
> I was wrong on this scenario and I'll explain where I was incorrect.
>
> Hints are stored for a downed node but they don't count towards me
I was wrong on this scenario and I'll explain where I was incorrect.
Hints are stored for a downed node but they don't count towards meeting a
consistency level.
Let's take 2 scenarios:
RF=6, Nodes=10
If you READ/WRITE with CL.QUORUM you will need 4 alive nodes if one is down
it will still have
On Sun, Nov 28, 2010 at 6:26 PM, David Boxenhorn wrote:
> Hints only happen when a node is unavailable and you are writing with CL.ANY
>
> If you never write with CL.ANY then you can turn off hinted handoff.
Hints happens at any consistency level. But they never helps to
reach the consistency lev
Thank you, Jake. It does... except that in another context you told me:
Hints only happen when a node is unavailable and you are writing with CL.ANY
If you never write with CL.ANY then you can turn off hinted handoff.
How do I reconcile this?
On Sun, Nov 28, 2010 at 7:11 PM, Jake Luciani wrote
Actually you can't. As explained in the wiki page linked:
"A hinted write does NOT count towards ConsistencyLevel requirements
of ONE, QUORUM, or ALL"
For CL.QUORUM, you do need QUORUM *replicas* to be alive to answer
the query. At RF=2, QUORUM=2 so no, you cannot take down any node
down or (some)
If you read/write data with quorum then you can safely take a node down in
this scenario. Subsequent writes will use hinted handoff to be passed to
the node when it comes back up.
More info is here: http://wiki.apache.org/cassandra/HintedHandoff
Does that answer your question?
-Jake
On Sun, N
to me it makes sense that if hinted handoff is off then cassandra cannot
satisfy 2 out of every 3rd writes writes when one of the nodes is down since
this node is the designated node of 2/3 writes.
But I don't remember reading this somewhere. Does hinted handoff affect
David's situation?
(David, di
For the vast majority of my data usage eventual consistency is fine (i.e.
CL=ONE) but I have a small amount of critical data for which I read and
write using CL=QUORUM.
If I have a cluster with 3 nodes and RF=2, and CL=QUORUM does that mean that
a value can be read from or written to any 2 nodes,
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