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From Daniel Curry <daniel.cu...@arrayent.com>
Subject Re: replication_factor: ?
Date Fri, 07 Mar 2014 15:41:13 GMT
Thank you.  Your answer makes sense, Is this documented any where

On 03/07/2014 07:37 AM, John Pyeatt wrote:
> You really don't want to set your RF to the same value as the number 
> of nodes in your cluster for a variety of reasons. The biggest one 
> being that if you have a node go down, your entire database is 
> essentially down because you will be unable to fulfil any requests 
> because the RF can never be met.
>
> The number of nodes in the cluster is essentially independent from 
> your replication factor.
>
> The more important relationship is between your RF value, latency, and 
> what consistency level you want to use for your reads and writes.
>
> If you are going to use QUORUM consistency level it makes a little 
> more sense to have your RF set to an odd number.
>
> So for example if you have a 12 node cluster with an RF=3 and you are 
> using QUORUM consistency that means that 2 nodes ((RF+1)/2) have to be 
> able to fulfil the request.
>
>
>
> On Fri, Mar 7, 2014 at 9:26 AM, Daniel Curry 
> <daniel.curry@arrayent.com <mailto:daniel.curry@arrayent.com>> wrote:
>
>       I would like to know on what is the rule of thumb for
>     "replication_factor:" number?
>     I think the answer is depends on how many nodes one has? IE: three
>     nodes will be the
>     number 3.  What would happen it I put the number 2 for a three
>     node cluster?
>        We are using both 3.2.4 and 3.1.3 ( that will be upgraded to
>     3.2.4).
>
>     Thank you.
>
>     -- 
>     Daniel Curry
>
>     Sr. Linux System Administrator, Network Operations
>
>     PGP : AD5A 96DC 7556 A020 B8E7 0E4D 5D5E 9BA5 C83E 8C92
>
>     Arrayent, Inc.
>     2317 Broadway Street, Suite 20
>     Redwood City, CA 94063
>     daniel@arrayent.com <mailto:daniel@arrayent.com>
>     650-260-4520 <tel:650-260-4520>
>
>
>
>
> -- 
> John Pyeatt
> Singlewire Software, LLC
> www.singlewire.com <http://www.singlewire.com/>
> ------------------
> 608.661.1184
> john.pyeatt@singlewire.com <mailto:john.pyeatt@singlewire.com>

-- 
Daniel Curry

Sr. Linux System Administrator, Network Operations

PGP : AD5A 96DC 7556 A020 B8E7 0E4D 5D5E 9BA5 C83E 8C92

Arrayent, Inc.
2317 Broadway Street, Suite 20
Redwood City, CA 94063
daniel@arrayent.com
650-260-4520


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