RandomPartitioner doubts

[Lucas Di Pentima <lu...@di-pentima.com.ar>]

Hello,

I'm using Cassandra 0.6.1 and ruby's library. I did some tests on my one-node development installation about using get_range method to scan the whole CF.

What I want to prove is if a CF with RandomPartitioner can be used with get_range getting a fixed number of keys at a time, until all are requested. I know the keys are saved in random order, but is that randomness fixed? or every time I ask for a range I'll get something different even if I pass the :start parameter?

As I said above, I did this test with a 1-node installation and I seem to get the same (random) order every call I do, but I don't know if this is a design feature or some collateral characteristic that is likely to change in the future, or even the behaviour is different with N-node clusters.

Thanks in advance!
--
Lucas Di Pentima - Santa Fe, Argentina
Jabber: lucas@di-pentima.com.ar
MSN: ldipenti75@hotmail.com

Re: RandomPartitioner doubts

[Jonathan Ellis <jb...@gmail.com>]

For each "page" of results, start with the key that was last in the
previous iteration, and you will get all the keys back.  The order is
random but consistent.

On Wed, Apr 21, 2010 at 7:55 PM, Lucas Di Pentima
<lu...@di-pentima.com.ar> wrote:
> Hello,
>
> I'm using Cassandra 0.6.1 and ruby's library. I did some tests on my one-node development installation about using get_range method to scan the whole CF.
>
> What I want to prove is if a CF with RandomPartitioner can be used with get_range getting a fixed number of keys at a time, until all are requested. I know the keys are saved in random order, but is that randomness fixed? or every time I ask for a range I'll get something different even if I pass the :start parameter?
>
> As I said above, I did this test with a 1-node installation and I seem to get the same (random) order every call I do, but I don't know if this is a design feature or some collateral characteristic that is likely to change in the future, or even the behaviour is different with N-node clusters.
>
> Thanks in advance!
> --
> Lucas Di Pentima - Santa Fe, Argentina
> Jabber: lucas@di-pentima.com.ar
> MSN: ldipenti75@hotmail.com
>
>
>
>
>