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Couple of quick observations and questions - <br>
<ol>
<li>G1 is officially supported in 7u4. (There are numerous
performance improvements that I recommend updating to the latest
jdk7 update, if possible)</li>
<li>What do you mean by old gen collection? Are you talking about
MixedGCs?</li>
<li>Instead of setting InitiatingHeapOccupancyPercent to zero,
have you tried resizing your young generation?</li>
<ol>
<li>I see the NewRatio, but that fixes the nursery to 640,
instead have you tried with a lower (than the min default) of
nursery using the NewSize option?</li>
</ol>
</ol>
<p>-Monica<br>
</p>
<br>
<br>
On 10/19/2012 12:13 AM, csewhiz wrote:
<blockquote
cite="mid:13a7770622f.3368361147554026191.2919233442948217281@zoho.com"
type="cite">
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<div
style="font-size:10pt;font-family:Verdana,Arial,Helvetica,sans-serif;">
<div>Hello All,</div>
<div> Sorry for posting this question in this mailing list. I
am unable to find any answer for this. I am trying to tune our
application for G1GC as we need very small pauses Below
500msec. </div>
<div> But the problem is when we are runing with G1GC (under
jdk 6_u37) Old generation of garbage collection only
happening when it is reaching the Max GC size I noticed on jdk
6U 37 if max heap size is 1GB then it is close to 1sec 2GB
close to 2 sec pauses. </div>
<div> </div>
<div> Is there any parameter to force the old gc happening
regularly. </div>
<div> </div>
<div>I am trying following setting, </div>
<div> </div>
<div>-Xms1280M -Xmx1280M -XX:+UseG1GC
-XX:MaxTenuringThreshold=15 -XX:SurvivorRatio=8 -XX:NewRatio=1
-XX:GCPauseIntervalMillis=7500 -XX:MaxGCPauseMillis=500
-XX:InitiatingHeapOccupancyPercent=0 -XX:ParallelGCThreads=7
-XX:ConcGCThreads=7 </div>
<div> </div>
<div>If anyone can give insight on how full GC is triggred
internals will be of great help.</div>
<div> </div>
<div>PS: I have tried without any option for G1 but not of much
help hence .. this one trying to be agressive ? but of not
much help.</div>
<div> </div>
<div> </div>
<div>Regards,</div>
<div>Soumit<br>
<br>
</div>
</div>
</blockquote>
<br>
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