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Hadoop, mail # user - NN Memory Jumps every 1 1/2 hours


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Edward Capriolo 2012-12-22, 04:24
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Adam Faris 2012-12-22, 04:59
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Edward Capriolo 2012-12-22, 12:54
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Michael Segel 2012-12-22, 15:42
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Joep Rottinghuis 2012-12-22, 17:17
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Edward Capriolo 2012-12-22, 17:51
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Suresh Srinivas 2012-12-22, 18:32
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Edward Capriolo 2012-12-23, 00:03
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Edward Capriolo 2012-12-23, 01:59
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Suresh Srinivas 2012-12-23, 03:23
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Edward Capriolo 2012-12-23, 18:34
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Joep Rottinghuis 2012-12-23, 19:00
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Suresh Srinivas 2012-12-24, 02:40
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Edward Capriolo 2012-12-27, 21:48
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Suresh Srinivas 2012-12-27, 22:08
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Re: NN Memory Jumps every 1 1/2 hours
Edward Capriolo 2012-12-27, 22:22
I am not sure GC had a factor. Even when I forced a GC it cleared 0%
memory. One would think that since the entire NameNode image is stored in
memory that the heap would not need to grow beyond that, but that sure does
not seem to be the case. a 5GB image starts off using 10GB of memory and
after "burn in" it seems to use about 15GB memory.

So really we say "the name node data has to fit in memory" but what we
really mean is "the name node data must fit in memory 3x"

On Thu, Dec 27, 2012 at 5:08 PM, Suresh Srinivas <[EMAIL PROTECTED]>wrote:

> You did free up lot of old generation with reducing young generation,
> right? The extra 5G of RAM for the old generation should have helped.
>
> Based on my calculation, for the current number of objects you have, you
> need roughly:
> 12G of total heap with young generation size of 1G. This assumes the
> average file name size is 32 bytes.
>
> In later releases (>= 0.20.204), several memory optimization and startup
> optimizations have been done. It should help you as well.
>
>
>
> On Thu, Dec 27, 2012 at 1:48 PM, Edward Capriolo <[EMAIL PROTECTED]
> >wrote:
>
> > So it turns out the issue was just the size of the filesystem.
> > 2012-12-27 16:37:22,390 WARN
> > org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode: Checkpoint
> done.
> > New Image Size: 4,354,340,042
> >
> > Basically if the NN image size hits ~ 5,000,000,000 you get f'ed. So you
> > need about 3x ram as your FSImage size. If you do not have enough you
> die a
> > slow death.
> >
> > On Sun, Dec 23, 2012 at 9:40 PM, Suresh Srinivas <[EMAIL PROTECTED]
> > >wrote:
> >
> > > Do not have access to my computer. Based on reading the previous
> email, I
> > > do not see any thing suspicious on the list of objects in the histo
> live
> > > dump.
> > >
> > > I would like to hear from you about if it continued to grow. One
> instance
> > > of this I had seen in the past was related to weak reference related to
> > > socket objects.  I do not see that happening here though.
> > >
> > > Sent from phone
> > >
> > > On Dec 23, 2012, at 10:34 AM, Edward Capriolo <[EMAIL PROTECTED]>
> > > wrote:
> > >
> > > > Tried this..
> > > >
> > > > NameNode is still Ruining my Xmas on its slow death march to OOM.
> > > >
> > > > http://imagebin.org/240453
> > > >
> > > >
> > > > On Sat, Dec 22, 2012 at 10:23 PM, Suresh Srinivas <
> > > [EMAIL PROTECTED]>wrote:
> > > >
> > > >> -XX:NewSize=1G -XX:MaxNewSize=1G
> > >
> >
>
>
>
> --
> http://hortonworks.com/download/
>
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Suresh Srinivas 2012-12-27, 22:41
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Edward Capriolo 2012-12-27, 22:58
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Suresh Srinivas 2012-12-27, 23:12