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From "Stu Hood" <stu.h...@rackspace.com>
Subject Re: mapreduce from cassandra to cassandra
Date Tue, 18 May 2010 17:52:33 GMT
A Cassandra OutputFormat was recently contributed, but I haven't had a chance to review it.
Any feedback you can give would be awesome:
https://issues.apache.org/jira/browse/CASSANDRA-1101

Thanks,
Stu

-----Original Message-----
From: "Jeff Zhang" <zjffdu@gmail.com>
Sent: Tuesday, May 18, 2010 4:39am
To: user@cassandra.apache.org
Subject: Re: mapreduce from cassandra to cassandra

BTW, maybe we should create an issue on jira for this problem if the
Cassandra committee think it is necessary.



On Tue, May 18, 2010 at 5:30 PM, Jeff Zhang <zjffdu@gmail.com> wrote:
> 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
>



-- 
Best Regards

Jeff Zhang



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