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From Héctor Izquierdo Seliva <izquie...@strands.com>
Subject Re: Replicate changes from DC1 to DC2, but not from DC2 to DC1
Date Tue, 22 Feb 2011 07:43:29 GMT
El mar, 22-02-2011 a las 08:46 +1300, Aaron Morton escribió:
> Take a look at the NetworkTopologyStrategy and/or the RackInferringSnitch together they
 decide where to place replicas. It's probably not a great idea to muck around with this stuff
though.
> 
> How about a hadoop job to pull out the data you want? It would be a full scan but in
parallel.

I looked at that, but correct me If i'm wrong, schema changes are
distributed to all nodes, and they all have to agree on a version, so I
can't have a keyspace A in DC1 with NetworkTopologyStrategy with options
= [{DC1:1,DC2:1}] and the same keyspace in DC2 with options [{DC2:1,
DC1:0}]. Is that correct?

> Aaron
> 
> On 22/02/2011, at 3:10 AM, Héctor Izquierdo Seliva <izquierdo@strands.com> wrote:
> 
> > 
> > Hi all.
> > 
> > Is there a way (besides changing the code) to replicate data from a Data
> > center 1 to a Data center 2, but not the other way around? I need to
> > have a preproduction environment with production data, and ideally with
> > only a fraction of the data (for example, by key preffixes). I have
> > poked around StorageProxy and I can make writes in DC2 not replicate to
> > DC1, and as long as I use DC_QUORUM it stays that way, but it
> > looks...dangerous. I could do a full key scan but it would take too
> > long.
> > 
> > Have anybody done something similar?
> > 
> > Thanks!
> > 
> > 



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