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MapReduce, mail # user - Re: Child JVM memory allocation / Usage


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Harsh J 2013-03-25, 04:56
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nagarjuna kanamarlapudi 2013-03-25, 05:02
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Hemanth Yamijala 2013-03-25, 06:31
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nagarjuna kanamarlapudi 2013-03-25, 08:44
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Hemanth Yamijala 2013-03-25, 13:09
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Re: Child JVM memory allocation / Usage
Ted 2013-03-25, 01:27
did you set the min heap size == your max head size? if you didn't,
free memory only shows you the difference between used and commit, not
used and max.

On 3/24/13, nagarjuna kanamarlapudi <[EMAIL PROTECTED]> wrote:
> Hi,
>
> I configured  my child jvm heap to 2 GB. So, I thought I could really read
> 1.5GB of data and store it in memory (mapper/reducer).
>
> I wanted to confirm the same and wrote the following piece of code in the
> configure method of mapper.
>
> @Override
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> public void configure(JobConf job) {
>
> System.out.println("FREE MEMORY -- "
>
> + Runtime.getRuntime().freeMemory());
>
> System.out.println("MAX MEMORY ---" + Runtime.getRuntime().maxMemory());
>
> }
>
>
> Surprisingly the output was
>
>
> FREE MEMORY -- 341854864  = 320 MB
> MAX MEMORY ---1908932608  = 1.9 GB
>
>
> I am just wondering what processes are taking up that extra 1.6GB of
> heap which I configured for the child jvm heap.
>
>
> Appreciate in helping me understand the scenario.
>
>
>
> Regards
>
> Nagarjuna K
>
--
Ted.
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nagarjuna kanamarlapudi 2013-03-25, 01:39
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Ted 2013-03-25, 03:27