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From Yonik Seeley <>
Subject Re: FW: Solr and Garbage Collection
Date Fri, 25 Sep 2009 20:09:03 GMT
On Fri, Sep 25, 2009 at 2:52 PM, Fuad Efendi <> wrote:
> Lowering heap helps GC?

Yes.  In general, lowering the heap can help or hurt.

Hurt: if one is running very low on memory, GC will be working harder
all of the time trying to find more memory and the % of time that GC
takes can go up.

Help: if one has massive heaps, full GCs may not happen as frequently,
but when they do they can be larger and cause more of a problem.  For
many apps, a .2 second pause every minute is preferable to a 10 second
pause every hour.

And of course the other reason to lower the heap size *if* you don't
need it that big is to leave more memory for other stuff, and for the
OS itself to cache the index files.


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