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From Lee Mighdoll <>
Subject Re: Long GC due to promotion failures
Date Wed, 22 Jan 2014 22:03:45 GMT
On Wed, Jan 22, 2014 at 11:35 AM, John Watson <> wrote:

> I thought PrintFLSStatistics was necessary for determining heap
> fragmentation? Or is it possible to see that without it as well?

I've found that easier parsing is more important than tracking indicators
of fragmentation.

Perm-Gen stays steady, but I'll enable it anyway to see if it has any
> affect.

I know CMSClassUnloadingEnabled is talked about in the context of permgen,
but it has an effect on the main heap as well.  In our case we saw DSE
nodes lock up for 10 minutes at a time trying to clear old gen; cured when
we added the flag.  It's a shot in the dark without more analysis, but just
turning on the flag is easy enough.


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