Re: set ReplicationFactor and Token at Column Family/SuperColumn level.

[Gary Dusbabek <gd...@gmail.com>]

On Thu, Aug 5, 2010 at 14:59, Zhong Li <zl...@voxeo.com> wrote:
> All,
>
> Thanks for Apache Cassandra Project, it is great project.
>
> This is my first time to use it. We install it on 10 nodes and runs great.
> The 10 nodes cross all 5 datacenters around the world.
>
> The big thing bother me is initial ring token. We have some Column Families.
> It is very hard to choose one token suitable for all CFs. Also some Column
> Families need higher Consistent Level and some don't. If we set
> ReplicationFactor too high, it is too costy for crossing datacenter,
> especially in otherside the world.
>
> I know we can setup multiple rings, but it costs more hardware.
>
> if Cassandra can implement  Ring,Token and RF on the CF level, or even
> SuperColumn level, it will make design much easier and more efficiency.

You can get separate replication factors by putting your column
families in separate keyspaces.

Token per CF (or even token per KS) isn't on the roadmap though.  You
can mitigate this to some extent by choosing row keys that play nicely
with your ring though.

Gary

>
> Is it possible?
>
> Thanks,
>
> Zhong