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


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Re: Child JVM memory allocation / Usage
nagarjuna kanamarlapudi 2013-03-25, 08:44
Hi Hemanth,

I tried out your suggestion loading 420 MB file into memory. It threw java
heap space error.

I am not sure where this 1.6 GB of configured heap went to ?
On Mon, Mar 25, 2013 at 12:01 PM, Hemanth Yamijala <
[EMAIL PROTECTED]> wrote:

> Hi,
>
> The free memory might be low, just because GC hasn't reclaimed what it
> can. Can you just try reading in the data you want to read and see if that
> works ?
>
> Thanks
> Hemanth
>
>
> On Mon, Mar 25, 2013 at 10:32 AM, nagarjuna kanamarlapudi <
> [EMAIL PROTECTED]> wrote:
>
>> io.sort.mb = 256 MB
>>
>>
>> On Monday, March 25, 2013, Harsh J wrote:
>>
>>> The MapTask may consume some memory of its own as well. What is your
>>> io.sort.mb (MR1) or mapreduce.task.io.sort.mb (MR2) set to?
>>>
>>> On Sun, Mar 24, 2013 at 3:40 PM, 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
>>> >
>>> > 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
>>> >
>>> >
>>> >
>>>
>>>
>>>
>>> --
>>> Harsh J
>>>
>>
>>
>> --
>> Sent from iPhone
>>
>
>