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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Doug<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I thank you for your feedback.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I use the ParNewGC, which according to Jon’s blog (<a
href="http://blogs.sun.com/jonthecollector/"><font color=black><span
style='color:windowtext'>http://blogs.sun.com/jonthecollector/</span></font></a>)
is the combination of "ParNew" + "Serial Old".<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Therefore, I do not use the UseConcMarkSweepGC.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I am using JDK 1.5.0_14.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I would not expect the young generation to be applied. The
logs seem to indicate that it is.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Alex A<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Jones, Doug H
[mailto:doug.jones@eds.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Monday, March 10, 2008 12:15
PM<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName w:st="on">Alex
Aisinzon</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: Avoiding the Young
Generation Guarantee</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=blue face=Verdana><span style='font-size:
10.0pt;font-family:Verdana;color:blue'>Hi Alex,</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=blue face=Verdana><span style='font-size:
10.0pt;font-family:Verdana;color:blue'>It is not supposed to be the case under
JVM version 5.0 on, it definitely was under JVM 1.4.2. I'm assuming you are
using ConcMarkSweepGC of the tenured area.</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=blue face=Verdana><span style='font-size:
10.0pt;font-family:Verdana;color:blue'>Doug. </span></font><o:p></o:p></p>
<blockquote style='margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p class=MsoNormal style='margin-bottom:12.0pt'><b><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma;font-weight:bold'>From:</span></font></b><font
size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
hotspot-gc-use-bounces@openjdk.java.net [mailto:hotspot-gc-use-bounces@openjdk.java.net]
<b><span style='font-weight:bold'>On Behalf Of </span></b><st1:PersonName
w:st="on">Alex Aisinzon</st1:PersonName><br>
<b><span style='font-weight:bold'>Sent:</span></b> Tuesday, 11 March 2008 7:50
a.m.<br>
<b><span style='font-weight:bold'>To:</span></b>
hotspot-gc-use@openjdk.java.net<br>
<b><span style='font-weight:bold'>Subject:</span></b> Avoiding the Young
Generation Guarantee</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>All<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Our application scales very well when more memory is allocated
to it.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>The Young Generation Guarantee limits that scalability as it
forces Full GC while plenty of space is still available in the tenured space.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>That guarantee forces us to use relatively smaller
nurseries.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> <a
href="http://java.sun.com/docs/hotspot/gc5.0/gc_tuning_5.html#0.0.0.0.%20Young%20Generation%20Guarantee%7Coutline">http://java.sun.com/docs/hotspot/gc5.0/gc_tuning_5.html#0.0.0.0.%20Young%20Generation%20Guarantee%7Coutline</a>
infers that this guarantee only applies to the serial collector but I see it
too with the parallel new collector.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Maybe I am confused in the collector terminology.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Could someone tell me how I can disable the young generation
guarantee?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Thanks in advance<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Alex A<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I have enclosed a snippet of the GC logs for analysis purposes.<o:p></o:p></span></font></p>
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