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From Jeremy Hanna <>
Subject Re: hadoop cassandra
Date Thu, 17 Mar 2011 14:04:09 GMT
You can start with a word count example that's only for hdfs.  Then you can replace the reducer
in that with the ReducerToCassandra that's in the cassandra word_count example.  You need
to match up your Mapper's output to the Reducer's input and set a couple of configuration
variables to tell it how to hook up to cassandra, but that should be it - a working word count
example that takes input from hdfs and outputs to cassandra.

We kind of figured that plenty of documentation was out there for hadoop with hdfs.  The word
count example just demonstrates something specific to cassandra.  However hadoop is so pluggable
that as long as the input and output types line up, you can mix and match most anything with
the inputformat and outputformat (like in word count you can output to cassandra or to the
local filesystem - there are two different inner classes).

Does that help?


On Mar 17, 2011, at 3:28 AM, Sagar Kohli wrote:

> hi all,
> is there any example of hadoop and cassandra integration where input is from hdfs and
out put to cassandra
> NOTE: i have gone through word count example provided with the source code, but it does
not have above case..
> regards
> Sagar
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