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From Pedro Costa <psdc1...@gmail.com>
Subject Memory Manager in Hadoop MR
Date Thu, 09 Dec 2010 11:05:55 GMT
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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