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" <[email protected]> Sent: Tuesday, May 18, 2010 4:39am To: [email protected] 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 <[email protected]> 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 <[email protected]> wrote: >> hbase - yes. But is that reusable for cassandra? >> >> On Tue, May 18, 2010 at 12:17 PM, Jeff Zhang <[email protected]> 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 <[email protected]> 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
