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Subject: Re: Cassandra users survey
From: "B. Todd Burruss" <bburruss@real.com>
To: cassandra-user@incubator.apache.org
Cc: cassandra-dev@incubator.apache.org
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Date: Fri, 20 Nov 2009 14:10:32 -0800
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I am evaluating "NoSQL" alternatives to your typical hard to scale
RDBMS, specifically Key/Value stores.  I'm not looking for query
capabilities.  I want very very very high availability with very very
large amounts of data.

I have reduced down my list to Cassandra, Voldemort, Riak, and CouchDB.
Voldemort doesn't seem far enough along to properly evaluate so it is on
the back burner.  Couch is used in a lot of places, but without the
"lounge" it doesn't scale, nor have any sort of HA story (and the lounge
is difficult at best to get installed and working.)  I should mention
Oracle is in use today.

That leaves Riak and Cassandra.  I like Cassandra because of the Rack
and DC awareness hooks.  This is a nice feature for those wanting 5 9's
of availability.

I haven't gotten to performance testing yet.  Just trying to verify that
the products do what they are supposed to, and understand the nuances
with each one.

What I'd like to see in Cassandra:

- flexible conflict resolution mechanism.  Not just "last write wins".
Give the client the ability to "merge" conflicting values.
- A nice web interface to cluster statistics and management.  Something
an operations team could lean on to examine the entire cluster.

thx!


On Fri, 2009-11-20 at 15:17 -0600, Jonathan Ellis wrote:
> Hi all,
> 
> I'd love to get a better feel for who is using Cassandra and what kind
> of applications it is seeing.  If you are using Cassandra, could you
> share what you're using it for and what stage you are at with it
> (evaluation / testing / production)? Also, what alternatives you
> evaluated/are evaluating would be useful.  Finally, feel free to throw
> in "I'd love to use Cassandra if only it did X" wishes. :)
> 
> I can start: Rackspace is using Cassandra for stats collection
> (testing, almost production) and as a backend for the Mail & Apps
> division (early testing).  We evaluated HBase, Hypertable, dynomite,
> and Voldemort as well.
> 
> Thanks,
> 
> -Jonathan
> 
> (If you're in stealth mode or don't want to say anything in public,
> feel free to reply to me privately and I will keep it off the record.)