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From Alain RODRIGUEZ <arodr...@gmail.com>
Subject Re: Read consistency
Date Thu, 17 Mar 2016 10:37:55 GMT
Hi Arko,

Never used that consistency level so far, but here is some information:
http://docs.datastax.com/en/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* and updates will incur a performance hit, effectively a
> degradation to one-third of normal. For in-depth information about this new
> consistency level, see the article,*Lightweight transactions in Cassandra*
> <http://www.datastax.com/dev/blog/lightweight-transactions-in-cassandra-2-0>
> .


 So it appears that a read using quorum should be fine (remember to use
local consistency level on a multi-DC environment if this is what you want
to do).

Never checked that on my own, just read that, fwiw.

C*heers,
-----------------------
Alain Rodriguez - alain@thelastpickle.com
France

The Last Pickle - Apache Cassandra Consulting
http://www.thelastpickle.com

2016-03-16 2:43 GMT+01:00 Arko Provo Mukherjee <arkoprovomukherjee@gmail.com
>:

> Hello,
>
> I am designing a system where for a situation, I need to have SERIAL
> consistency during writes.
>
> I understand that if the write was with QUORUM, a Read with QUORUM would
> have fetched me the correct (most recent) data.
>
> My question is what is the minimum consistency level required for read,
> when my write consistency is SERIAL.
>
> Any pointers would be much appreciated.
>
> Thanks & regards
> Arko
>
>

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