<div dir="ltr"><div><br></div>Thanks for the quick reply. We are trying to optimize for throughput.<div><br></div><div><br><div>PS: Putting these logs through <a href="https://github.com/chewiebug/GCViewer" target="_blank">GCViewer</a> put the throughput at 95.5 % <br></div><div>which we want to improve </div><div><br></div><div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Aug 20, 2015 at 5:33 PM, Tao Mao <span dir="ltr"><<a href="mailto:yiyeguhu@gmail.com" target="_blank">yiyeguhu@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi,<div><br></div><div>Do you mainly optimize for throughtput or latency? What are the requirements?</div><div><br></div><div>Thanks.</div><span><font color="#888888"><div>Tao Mao</div><div><br></div><div><br></div><div><br></div></font></span></div><div class="gmail_extra"><br><div class="gmail_quote"><div><div>On Thu, Aug 20, 2015 at 5:27 PM, D vd Reddy <span dir="ltr"><<a href="mailto:dvdeepankar.reddy@gmail.com" target="_blank">dvdeepankar.reddy@gmail.com</a>></span> wrote:<br></div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div><div dir="ltr">Hi, <div><br></div><div>We are running G1 GC with heap size of around 140 - 150 GB, we are observing high object copy times during young gc (> 80 % of the total GC time). </div><div>Is this expected or is there anything we are doing wrong. I am not able to find any documentation of optimizing high object copy times, </div><div>any help would be appreciated </div><div><br></div><div><br></div><div><font face="monospace, monospace">CommandLine flags: -XX:+AggressiveOpts -XX:InitialHeapSize=154618822656 -XX:+ManagementServer </font></div><div><font face="monospace, monospace">-XX:MaxGCPauseMillis=1000 </font><span style="font-family:monospace,monospace">-XX:MaxHeapSize=154618822656 -XX:MaxMetaspaceSize=268435456 </span></div><div><span style="font-family:monospace,monospace">-XX:MetaspaceSize=268435456 -XX:ObjectAlignmentInBytes=16 </span></div><div><font face="monospace, monospace">-XX:+PrintGC -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+UnlockExperimentalVMOptions </font></div><div><font face="monospace, monospace">-XX:-UseCompressedOops -XX:+UseG1GC </font><br></div><div><br></div><div><br></div><div>Sample young GC snippet </div><div><br></div><div><table style="border-collapse:collapse;border-spacing:0px;color:rgb(51,51,51);font-family:Helvetica,arial,nimbussansl,liberationsans,freesans,clean,sans-serif,'Segoe UI Emoji','Segoe UI Symbol';font-size:13px;line-height:18.2px"><tbody><tr></tr><tr><td style="padding:0px 10px;vertical-align:top;font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace;font-size:12px;white-space:pre-wrap;overflow:visible;word-wrap:normal"><br></td></tr></tbody></table><br></div><div><br></div><div><div><font face="monospace, monospace">4416.985: [GC pause (G1 Evacuation Pause) (young), 0.3180932 secs]</font></div><div><font face="monospace, monospace">  [Parallel Time: 291.1 ms, GC Workers: 23]</font></div><div><font face="monospace, monospace">   [GC Worker Start (ms): Min: 4416985.5, Avg: 4416985.9, Max: 4416986.2, Diff: 0.7]</font></div><div><font face="monospace, monospace">   [Ext Root Scanning (ms): Min: 1.2, Avg: 1.7, Max: 4.4, Diff: 3.2, Sum: 38.5]</font></div><div><font face="monospace, monospace">   [Update RS (ms): Min: 36.3, Avg: 39.4, Max: 40.0, Diff: 3.8, Sum: 906.0]</font></div><div><font face="monospace, monospace">     [Processed Buffers: Min: 47, Avg: 80.9, Max: 124, Diff: 77, Sum: 1861]</font></div><div><font face="monospace, monospace">   [Scan RS (ms): Min: 0.5, Avg: 1.0, Max: 1.1, Diff: 0.6, Sum: 22.5]</font></div><div><font face="monospace, monospace">   [Code Root Scanning (ms): Min: 0.0, Avg: 0.0, Max: 0.0, Diff: 0.0, Sum: 0.6]</font></div><div><font face="monospace, monospace">   [Object Copy (ms): Min: 247.1, Avg: 247.2, Max: 247.5, Diff: 0.4, Sum: 5686.4]</font></div><div><font face="monospace, monospace">   [Termination (ms): Min: 0.0, Avg: 0.3, Max: 0.4, Diff: 0.4, Sum: 7.5]</font></div><div><font face="monospace, monospace">   [GC Worker Other (ms): Min: 0.0, Avg: 0.3, Max: 0.7, Diff: 0.7, Sum: 7.6]</font></div><div><font face="monospace, monospace">   [GC Worker Total (ms): Min: 289.4, Avg: 290.0, Max: 290.4, Diff: 1.0, Sum: 6669.3]</font></div><div><font face="monospace, monospace">   [GC Worker End (ms): Min: 4417275.5, Avg: 4417275.8, Max: 4417276.2, Diff: 0.7]</font></div><div><font face="monospace, monospace">  [Code Root Fixup: 0.4 ms]</font></div><div><font face="monospace, monospace">  [Code Root Migration: 0.5 ms]</font></div><div><font face="monospace, monospace">  [Clear CT: 9.3 ms]</font></div><div><font face="monospace, monospace">  [Other: 16.8 ms]</font></div><div><font face="monospace, monospace">   [Choose CSet: 0.0 ms]</font></div><div><font face="monospace, monospace">   [Ref Proc: 3.7 ms]</font></div><div><font face="monospace, monospace">   [Ref Enq: 0.1 ms]</font></div><div><font face="monospace, monospace">   [Free CSet: 6.0 ms]</font></div><div><font face="monospace, monospace">  [Eden: 80.3G(80.3G)->0.0B(81.7G) Survivors: 2944.0M->2176.0M Heap: 126.4G(144.0G)->45.4G(144.0G)]</font></div><div><font face="monospace, monospace"> [Times: user=6.84 sys=0.01, real=0.32 secs] </font></div><div><font face="monospace, monospace"><br></font></div><div><font face="arial, helvetica, sans-serif">Full GC Log for a period of run : <a href="https://gist.github.com/dvdreddy/5ecf9a58a3f309e8bb60" target="_blank">https://gist.github.com/dvdreddy/5ecf9a58a3f309e8bb60</a></font></div><div><font face="arial, helvetica, sans-serif"><br></font></div><div><font face="arial, helvetica, sans-serif"><br></font></div><div><font face="arial, helvetica, sans-serif">Thanks in advance</font></div><div><font face="arial, helvetica, sans-serif"><br></font></div><div><font face="monospace, monospace"><br></font></div><div><br></div></div></div>
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