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MapReduce >> mail # user >> why multiple checkpoint nodes?


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Thanh Do 2013-04-18, 16:05
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shashwat shriparv 2013-04-18, 17:07
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Thanh Do 2013-04-18, 17:20
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Bertrand Dechoux 2013-04-18, 19:45
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Mohammad Tariq 2013-04-18, 20:07
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Thanh Do 2013-04-19, 02:54
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Re: why multiple checkpoint nodes?
For more information : https://issues.apache.org/jira/browse/HADOOP-7297

It has been corrected but the stable documentation is still the 1.0.4
(previous to correction).

See
* http://hadoop.apache.org/docs/r1.0.4/hdfs_user_guide.html
* http://hadoop.apache.org/docs/r1.1.1/hdfs_user_guide.html
* http://hadoop.apache.org/docs/r1.1.2/hdfs_user_guide.html

Regards

Bertrand
On Thu, Apr 18, 2013 at 9:45 PM, Bertrand Dechoux <[EMAIL PROTECTED]>wrote:

> It would be important to point the document (which I believe is
> http://hadoop.apache.org/docs/stable/hdfs_user_guide.html) and the
> version of Hadoop you are interested in. At one time, the documentation was
> misleading. The 1.x version didn't have checkpoint/backup nodes only the
> secondary namenode. I don't believe it has changed but I might be wrong (or
> the documentation still hasn't been fixed). The 2.x version will have
> namenode HA which will be the final solution.
>
> Regards
>
> Bertrand
>
>
> On Thu, Apr 18, 2013 at 7:20 PM, Thanh Do <[EMAIL PROTECTED]> wrote:
>
>> so reliability (to prevent metadata loss) is the main motivation for
>> multiple checkpoint nodes?
>>
>> Does anybody use multiple checkpoint nodes in real life?
>>
>> Thanks
>>
>>
>> On Thu, Apr 18, 2013 at 12:07 PM, shashwat shriparv <
>> [EMAIL PROTECTED]> wrote:
>>
>>> more checkpoint nodes means more backup of the metadata :)
>>>
>>> *Thanks & Regards    *
>>>
>>> ∞
>>> Shashwat Shriparv
>>>
>>>
>>>
>>> On Thu, Apr 18, 2013 at 9:35 PM, Thanh Do <[EMAIL PROTECTED]> wrote:
>>>
>>>> Hi all,
>>>>
>>>> The document says "Multiple checkpoint nodes may be specified in the
>>>> cluster configuration file".
>>>>
>>>> Can some one clarify me that why we really need to run multiple
>>>> checkpoint nodes anyway? Is it possible that while checkpoint node A is
>>>> doing checkpoint, and check point node B kicks in and does another
>>>> checkpoint?
>>>>
>>>> Thanks,
>>>> Thanh
>>>>
>>>
>>>
>>
>
>
> --
> Bertrand Dechoux
>

--
Bertrand Dechoux