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From Ted Yu <yuzhih...@gmail.com>
Subject Re: Memory Manager in Hadoop MR
Date Thu, 09 Dec 2010 18:17:26 GMT
For 1, TMMT uses ProcessTree to check for task that is running beyond
memory-limits and kills it.

On Thu, Dec 9, 2010 at 3:05 AM, Pedro Costa <psdc1978@gmail.com> wrote:

> Hi,
>
> 1 - Hadoop MR contains a TaskMemoryManagerThread class that is used to
> manage memory usage of tasks running under a TaskTracker. Why Hadoop
> MR needs a class to manage memory? Why it couldn't rely on the JVM, or
> this class is here for another purpose?
>
> 2 - How the JT knows that a Map or Reduce Task finished? Is through
> the heartbeat?
>
> Thanks
>
> --
> Pedro
>

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