Avoiding the Young Generation Guarantee
Y Srinivas Ramakrishna
Y.S.Ramakrishna at Sun.COM
Mon Mar 10 19:42:45 UTC 2008
Relatedly, you might also want to (separately) try the +UseParallelGC collector
-- in later versions of 5 (5u8 and later, AFAIR) it provides a
parallel old collector as well: -XX:+UseParallelOldGC.
Even otherwise, +UseParallelGC provides adaptive/dynamic
sizing of the generations, which might provide you with better
throughput than the static hand-tuning you would typically do
The GC tuning guide provides further details (see "Ergonomics"
and "Parallel Compaction").
----- Original Message -----
From: Alex Aisinzon <aaisinzon at guidewire.com>
Date: Monday, March 10, 2008 12:36 pm
Subject: RE: Avoiding the Young Generation Guarantee
To: Y Srinivas Ramakrishna <Y.S.Ramakrishna at Sun.COM>
Cc: hotspot-gc-use at openjdk.java.net
> I thank you for the pointer. I will try that option very soon and report
> on it.
> Alex Aisinzon
> -----Original Message-----
> From: Y Srinivas Ramakrishna [mailto:Y.S.Ramakrishna at Sun.COM]
> Sent: Monday, March 10, 2008 12:24 PM
> To: Alex Aisinzon
> Cc: hotspot-gc-use at openjdk.java.net
> Subject: Re: Avoiding the Young Generation Guarantee
> -XX:+HandlePromotionFailure should allow you to circumvent the pessimal
> (AFAIR, that was made the default behaviour in 6.0, but was not in 5.0,
> you also used the CMS collector; but the history is a bit vague in my
> so you should of course check this rather than take my word for it.)
> -- ramki
> ----- Original Message -----
> From: Alex Aisinzon <aaisinzon at guidewire.com>
> Date: Monday, March 10, 2008 11:50 am
> Subject: Avoiding the Young Generation Guarantee
> To: hotspot-gc-use at openjdk.java.net
> > All
> > Our application scales very well when more memory is allocated to it.
> > The Young Generation Guarantee limits that scalability as it forces
> > GC while plenty of space is still available in the tenured space.
> > That guarantee forces us to use relatively smaller nurseries.
> > %20Generation%20Guarantee%7Coutline infers that this guarantee only
> > applies to the serial collector but I see it too with the parallel new
> > collector.
> > Maybe I am confused in the collector terminology.
> > Could someone tell me how I can disable the young generation
> > Thanks in advance
> > Alex A
> > I have enclosed a snippet of the GC logs for analysis purposes.
> > _______________________________________________
> > hotspot-gc-use mailing list
> > hotspot-gc-use at openjdk.java.net
> > http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use
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