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Hadoop >> mail # user >> Re: Is the input values for reduce method sorted in any order?


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Re: Is the input values for reduce method sorted in any order?
MR will partition and sort inputs by keys by the key comparator, and
then group them together when reading back via a grouping comparator
(which is usually the same as the key comparator). It will not re-sort
the values nor look at any of the value's fields during this process.

If you want your values to be sorted, implementing secondary sort
would need to happen wherein you extract the value-sort attributes
onto your keys and have them grouped differently.

On Tue, Mar 26, 2013 at 10:55 AM, jingguo yao <[EMAIL PROTECTED]> wrote:
> Is the Iterable values associated with a key sorted in any order?  Are
> there are any configuration options controlling how the input values are
> sorted?
>
> I know that the secondary sort way can be used to achieve the same
> effect. I am not asking for a workaround.
>
> --
> Jingguo

--
Harsh J
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB