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From Jeff Zhang <zjf...@gmail.com>
Subject Re: mapreduce from cassandra to cassandra
Date Tue, 18 May 2010 09:30:54 GMT
reuse is not possible, but I think it won't hard for cassandra to
implement a ColumnFamilyOutputFormat. In my opinion, the
ColumnFamilyOutputFormat should be easier to implement than
ColumnFamilyInputFormat, because you don't need to think about split
in the implementation of OutputFormat.





On Tue, May 18, 2010 at 5:22 PM, Ran Tavory <rantav@gmail.com> wrote:
> hbase - yes. But is that reusable for cassandra?
>
> On Tue, May 18, 2010 at 12:17 PM, Jeff Zhang <zjffdu@gmail.com> wrote:
>>
>> I believe it is possible to write result back to cassandra. If I
>> remember correctly, HBase has both InputFormat and OutputFormat for
>> hadoop.
>>
>>
>>
>>
>> On Tue, May 18, 2010 at 5:08 PM, Ran Tavory <rantav@gmail.com> wrote:
>> > In the wordcount example the process reads from cassandra and the result
>> > is
>> > written to a local file at /tmp/word_count*
>> > Is it possible to read from cassandra and write the result back to
>> > cassandra
>> > to a specified cf/row/column?
>> > I see that there exists a ColumnFamilyInputFormat but not
>> > ColumnFamilyOutputFormat or something like that
>> >
>> > (in http://svn.apache.org/repos/asf/cassandra/trunk/src/java/org/apache/cassandra/hadoop/)
>> > My knowledge about hadoop and mr is pretty basic so maybe I'm missing
>> > something simple, lmk, thanks!
>>
>>
>>
>> --
>> Best Regards
>>
>> Jeff Zhang
>
>



-- 
Best Regards

Jeff Zhang

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