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From graham sanderson <gra...@vast.com>
Subject Re: Consistency Level One Question
Date Fri, 21 Feb 2014 06:54:13 GMT
Note also; that reading at ONE there will be no read repair, since the coordinator does not
know that another replica has stale data (remember at ONE, basically only one node is asked
for the answer).

In practice for our use cases, we always write at LOCAL_QUORUM (failing the whole update if
that doesn’t work - stale data is OK if >1 node is down), and we read at LOCAL_QUORUM,
but (because stale data is better than no data), we will fall back per read request to LOCAL_ONE
if we detect that there were insufficient nodes - this lets us cope with 2 down nodes in a
3 replica environment (or more if the nodes are not consecutive in the ring).

On Feb 20, 2014, at 11:21 PM, Drew Kutcharian <drew@venarc.com> wrote:

> Hi Guys,
> 
> I wanted to get some clarification on what happens when you write and read at consistency
level 1. Say I have a keyspace with replication factor of 3 and a table which will contain
write-once/read-only wide rows. If I write at consistency level 1 and the write happens on
node A and I read back at consistency level 1 from another node other than A, say B, will
C* return “not found” or will it trigger a read-repair before responding? In addition,
what’s the best consistency level for reading/writing write-once/read-only wide rows?
> 
> Thanks,
> 
> Drew
> 


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