Koji,

There is no Java options specified other than -Xmx24g, what are some of the
recommended options for namenode?

Thanks,

Felix

On Wed, Jan 18, 2012 at 3:39 PM, Koji Noguchi <knogu...@yahoo-inc.com>wrote:

>  Hi Felix,
>
> Taking  jmap –histo:live <pid> would tell you what’s occupying the heap.
>
> Are you using  UseConcMarkSweepGC?
> If yes, and if you see bunch of
>   java.net.SocksSocketImpl
>   sun.nio.ch.SocketChannelImpl
> from jmap histo outputs, try passing    -XX:-CMSConcurrentMTEnabled .
>
> Background: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7113118
>
> Koji
>
>
>
>
> On 1/18/12 3:23 PM, "felix gao" <gre1...@gmail.com> wrote:
>
> Hi guys,
>
> we are running Hadoop 0.20.2+228, the namenode process's memory grows
> overtime to occupy over 18GB.  However, if I restart the namenode, it only
> occupies about 10GB after it is stable.  I am wondering if there is anyway
> to figure out what is going on with namenode that causes it to grow very
> rapidly and if there are any tools to make the namenode printout some
> useful information on what is holding onto that memory.
>
> Thanks,
>
> Felix
>
>

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