try tools/stress in the source distribution. 

Cheers

-----------------
Aaron Morton
Freelance Developer
@aaronmorton

On 3/03/2012, at 6:01 AM, A J wrote:

What is the best way to create millions of test data in Cassandra ?

I would like to have some script where I first insert say 100 rows in
a CF. Then reinsert the same data on 'server side' with new unique
key. That will make it 200 rows. Then continue the exercise a few
times till I get lot of records.
I don't care if the column names and values are identical between the
different rows. Just a lot of records generated for a few seed
records.

The rows are very fat. So I don't want to use any client side
scripting that would push individual or batched rows to cassandra.

Thanks for any tips.