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From <Milind.Bhandar...@emc.com>
Subject Re: Very strange Java Collection behavior in Hadoop
Date Wed, 21 Mar 2012 22:14:13 GMT
Owen,

Is there interest in reverting hadoop-2399 in 0.23.x ?

- Milind

---
Milind Bhandarkar
Greenplum Labs, EMC
(Disclaimer: Opinions expressed in this email are those of the author, and
do not necessarily represent the views of any organization, past or
present, the author might be affiliated with.)



On 3/19/12 11:20 PM, "Owen O'Malley" <omalley@apache.org> wrote:

>On Mon, Mar 19, 2012 at 11:05 PM, madhu phatak <phatak.dev@gmail.com>
>wrote:
>
>> Hi Owen O'Malley,
>>  Thank you for that Instant reply. It's working now. Can you explain me
>> what you mean by "input to reducer is reused" in little detail?
>
>
>Each time the statement "Text value = values.next();" is executed it
>always
>returns the same Text object with the contents of that object changed.
>When
>you add the Text to the list, you are adding a pointer to the same Text
>object. At the end you have 6 copies of the same pointer instead of 6
>different Text objects.
>
>The reason that I said it is my fault, is because I added the optimization
>that causes it. If you are interested in Hadoop archeology, it was
>HADOOP-2399 that made the change. I also did HADOOP-3522 to improve the
>documentation in the area.
>
>-- Owen


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