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MapReduce >> mail # user >> Does mapred.local.dir is important factor in reducer side?

Majid Azimi 2012-12-31, 16:14
Harsh J 2012-12-31, 19:25
Ted Dunning 2012-12-31, 19:17
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Re: Does mapred.local.dir is important factor in reducer side?

Do note that the local directory configs accept URIs in 2.x releases,
allowing users to plug alternative filesystems if they wanted to.

On Tue, Jan 1, 2013 at 12:47 AM, Ted Dunning <[EMAIL PROTECTED]> wrote:
> Hadoop, The Definitive Guide is only talking about Apache, CDH and
> Hortonworks here.
> The MapR distribution does not have this limitation and thus is one solution
> for this problem.
> Another solution is to do partial aggregates such as with a combiner.
> On Mon, Dec 31, 2012 at 8:14 AM, Majid Azimi <[EMAIL PROTECTED]>
> wrote:
>> Hadoop the definitive guide says:
>> intermediate results on the mapper side is written to local disk at
>> mapred.local.dir location so if this location does not have enough space the
>> map will fail.
>> I want to know if this is true on the reducer side. Output of all mappers
>> will merge at reducer side. In which location this merge happens? If that
>> location does not have enough space does reducer fail? What is the solution
>> for MapReduce jobs if intermediat results for some keys is more than local
>> disk of reducer?

Harsh J