You are viewing a plain text version of this content. The canonical link for it is here.

Posted to user@cassandra.apache.org by Ramzi Rabah <rr...@playdom.com> on 2009/11/16 18:59:36 UTC

How even distributed is MD5 Hash in RandomPartitioner

Hi everyone,

Since Cassandra uses MD5 hash internally to hash the keys to place on
the ring in a RandomPartitioner, how evenly distributed are the hashes
across the hash space?

Does it make sense to divide the hash space equally by the number of
machines available using InitialToken(ie, If there are 10 machines,
each will handle 1/10th of maximum hash value) and expect that the
machines will get a reasonably equal load?

Thanks
Ray

Re: How even distributed is MD5 Hash in RandomPartitioner

Posted by Jonathan Ellis <jb...@gmail.com>.

Yes.  That is what most people using RP do.

On Mon, Nov 16, 2009 at 11:59 AM, Ramzi Rabah <rr...@playdom.com> wrote:
> Hi everyone,
>
> Since Cassandra uses MD5 hash internally to hash the keys to place on
> the ring in a RandomPartitioner, how evenly distributed are the hashes
> across the hash space?
>
> Does it make sense to divide the hash space equally by the number of
> machines available using InitialToken(ie, If there are 10 machines,
> each will handle 1/10th of maximum hash value) and expect that the
> machines will get a reasonably equal load?
>
> Thanks
> Ray
>