Just to play devils advocate... when was the last time someone benchmarked Cassandra? There's been a lot of changes and a couple releases since the last version I saw benchmarks for.

On Sun, Dec 6, 2009 at 12:34 AM, Matt Revelle <mrevelle@gmail.com> wrote:
Cassandra performance likely still beats HBase, but according to the "Powered By" page on the HBase wiki it is being used to handle realtime requests by StumbleUpon, Meetup, and Streamy (http://wiki.apache.org/hadoop/Hbase/PoweredBy).

These two documents contain some performance numbers:
http://static.last.fm/johan/nosql-20090611/hbase_nosql.pdf  (skip to page 22)
http://www.slideshare.net/schubertzhang/hbase-0200-performance-evaluation

Both Cassandra and HBase are useful tech, I just wanted to point out that HBase performance has improved over the past year and it can handle realtime requests.

On Dec 5, 2009, at 11:08 PM, Tim Estes wrote:

> Can you link/reference those? I haven't seen random read or write performance numbers published around V0.20 Hbase that are within 5x of Cassandra. I'm very curious about this...
>
> Sent from my iPhone
>
> On Dec 5, 2009, at 11:05 PM, "Matt Revelle" <mrevelle@gmail.com> wrote:
>
>> On Dec 5, 2009, at 21:45, Joe Stump <joe@joestump.net> wrote:
>>
>>>
>>> On Dec 5, 2009, at 7:41 PM, Bill Hastings wrote:
>>>
>>>> [Is] HBase used for real timish applications and if so any ideas what the largest deployment is.
>>>
>>> I don't know of anyone off the top of my head who's using anything built on top of Hadoop for a real-time environment. Hadoop just wasn't built for that. It was built, like MapReduce, for crunching absurd amounts of data across hundreds of nodes in a "reasonable" amount of time.
>>>
>>> Just my $0.02.
>>>
>>> --Joe
>>>
>>
>> While Hadoop MapReduce isn't meant for realtime use, HBase can handle it.
>>
>> Over last summer there were some benchmarks included in HBase/Hadoop presentations that showed, IIRC, performance comparable to Cassandra.
>>