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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">Hi Charlie,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">This is solaris OS and there is flag argv[46]: -XX:+UseLargePages which is enabled, do you recommend to disable it.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">Also per Thomas suggestion I am trying to figure out Java 1.8 compatible with our Apps and will use that in further testing.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">Thanks,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">Amit Mishra<o:p></o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> charlie hunt [mailto:charlie.hunt@oracle.com]
<br>
<b>Sent:</b> Saturday, February 4, 2017 00:12<br>
<b>To:</b> Thomas Schatzl <thomas.schatzl@oracle.com><br>
<b>Cc:</b> Amit Mishra <amit.mishra@redknee.com>; hotspot-gc-use@openjdk.java.net<br>
<b>Subject:</b> Re: Need help on G1 GC young gen Update RS and Scan RS pause reduction<o:p></o:p></span></p>
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<p class="MsoNormal">> “- from one gc to another, just for these four gcs, sys time is relatively high.â€<o:p></o:p></p>
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<p class="MsoNormal">Assuming this is on Linux … perhaps double check that THP (transparent huge pages) is disabled.<o:p></o:p></p>
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<p class="MsoNormal">charlie<o:p></o:p></p>
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<p class="MsoNormal">On Feb 3, 2017, at 7:01 AM, Thomas Schatzl <<a href="mailto:thomas.schatzl@oracle.com">thomas.schatzl@oracle.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif">Hi Amit,<br>
<br>
On Fri, 2017-02-03 at 11:09 +0000, Amit Mishra wrote:<br style="font-variant-caps: normal;orphans: auto;text-align:start;widows: auto;-webkit-text-stroke-width: 0px;word-spacing:0px">
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif">Hi Thomas/team,<br>
<br>
<br>
I have put all parameters as per your suggestion but somehow the<br>
minor gc pauses are still haunting.<br>
<br>
Attaching GC logs.<br>
<br>
<br>
bash-3.2$ grep -i young gcstats.log.10636|cut -d, -f2|awk -F" "<br>
'{print $1}'|awk '$1 > 1'<br>
1.1273134<br>
1.1683221<br>
3.5504848<br>
5.2693987<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif"><br>
looking at these log entries, there seems to be something going on<br>
that seems outside of VM control:<br>
<br>
- from one gc to another, just for these four gcs, sys time is<br>
relatively high.<br>
<br>
- for the last two occurrences, at least one thread is hanging in "Ext<br>
Root Scanning" for almost all of the gc time for no obvious reason.<br>
<br>
- there do not seem to be an unusually large amount of changes in the<br>
amount of work done in the particular phases that would raise immediate<br>
concerns to me.<br>
<br>
Please try to find out the source of the high sys time and maybe even<br>
what causes it. I can't help a lot in that area, but dtrace seems a<br>
good starting point as suggested earlier.<br>
<br>
I think we went through most obvious tunings now, but maybe somebody else has more ideas. I don't at this time.<br>
<br>
The jdk (7u45) you are using is also very old, so even if we find that<br>
there is something wrong with g1 in particular, I kind of doubt there<br>
are many more useful knobs to turn with that version (or even<br>
appropriate logging to find out about the actual issue). Since 7u45<br>
release, there have been hundreds of changes that in particular improve<br>
G1 performance, so please consider upgrading to something more recent<br>
(at least latest 8u, preferably to me some test runs with 9ea).<br>
Upgrading alone might already help.<br>
<br>
Thanks,<br>
Thomas<br>
<br>
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</span><a href="http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use"><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif">http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use</span></a><o:p></o:p></p>
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