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Hive >> mail # user >> map tasks are taking ever when running job on 24 TB


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Srinivas Surasani 2013-04-25, 21:33
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Sanjay Subramanian 2013-04-25, 22:10
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Re: map tasks are taking ever when running job on 24 TB
How about running it via sub-queries where each query runs over a subset of
the data and has a better chance of finishing. I fear that the amount of
data to shuffle might be too big and you might be running out of
scratch/temp space. Did you verify that the job does not fail due to out of
disk space before the shuffle/reduce can kick in ?

-Viral
On Thu, Apr 25, 2013 at 3:10 PM, Sanjay Subramanian <
[EMAIL PROTECTED]> wrote:

>  That’s a lot of partitions for one Hive Job ! Not sure if that itself is
> the root of the issues….There have been quite a few discussions on max
> 1000-ish number of partitions as good…
> Is your use case conducive too using Combiners (though they cannot be
> guaranteed to be called)
> Thanks
> sanjay
>
>   From: Srinivas Surasani <[EMAIL PROTECTED]>
> Reply-To: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
> Date: Thursday, April 25, 2013 2:33 PM
> To: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
> Subject: map tasks are taking ever when running job on 24 TB
>
>
> Hi,
>
> I'm running hive job on 24TB dataset (on 34560 partitions ). here about
> 500 to 1000 mappers are getting succeded (total of 80000) and rest mappaers
> are taking for ever ( their status stays at 0% all times ).  Is there any
> limitations on number of partitions/dataset ? are there any paraemeters to
> set  here?
>
> Same job  is suceeding on 18TB (25920 partitions ).
>
> I already set below in my hive query.
> set mapreduce.jobtracker.split.metainfo.maxsize=-1;
>
>
> Regards,
> Srinivas
>
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Srinivas Surasani 2013-04-25, 23:29