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Posted to user@cassandra.apache.org by Sanjay Acharya <sa...@yahoo.com> on 2010/12/03 21:33:50 UTC

Cassandra Map-Reduce

We are in the process of evaluating Cassandra for our needs and we expect to use 
parallelism for analytics on collected data. The following BLOG mentions that 

Cassandra's Map-Reduce support does not support multiple column families 
http://allthingshadoop.com/2010/04/24/running-hadoop-mapreduce-with-cassandra-nosql/


Has the same proven to be a challenge or blockers for those using the Map-Reduce 
functionality? Please share your experience. Also are there plans to support 
multiple column family map-reduce functionality?

Re: Cassandra Map-Reduce

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

It doesn't make sense at the RecordReader layer to consume multiple
CFs.  Chaining them together is usually best left to a higher level
like Pig, although you could do it manually if you wanted to badly
enough.

On Fri, Dec 3, 2010 at 2:33 PM, Sanjay Acharya <sa...@yahoo.com> wrote:
> We are in the process of evaluating Cassandra for our needs and we expect to
> use parallelism for analytics on collected data. The following BLOG mentions
> that
> Cassandra's Map-Reduce support does not support multiple column families
> http://allthingshadoop.com/2010/04/24/running-hadoop-mapreduce-with-cassandra-nosql/
>
> Has the same proven to be a challenge or blockers for those using the
> Map-Reduce functionality? Please share your experience. Also are there plans
> to support multiple column family map-reduce functionality?
>
>
>



-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com

Re: Cassandra Map-Reduce

Posted by Jeremy Hanna <je...@gmail.com>.

I created to explore doing that - it would seem like a reasonable thing to do with a batch/analytic/MR operation.  You might chime in to explain your use case on the ticket.

https://issues.apache.org/jira/browse/CASSANDRA-1821

On Dec 3, 2010, at 2:33 PM, Sanjay Acharya wrote:

> We are in the process of evaluating Cassandra for our needs and we expect to use parallelism for analytics on collected data. The following BLOG mentions that 
> Cassandra's Map-Reduce support does not support multiple column families http://allthingshadoop.com/2010/04/24/running-hadoop-mapreduce-with-cassandra-nosql/
> 
> Has the same proven to be a challenge or blockers for those using the Map-Reduce functionality? Please share your experience. Also are there plans to support multiple column family map-reduce functionality?
> 
> 
>