occasional ParNew times of 15+ seconds

Fri Oct 28 22:43:01 UTC 2016

While typical ParNew GC times are 50ms, our application is occasionally
hitting ParNew times that are over 15 seconds for one of our customers, and
we have no idea why. Looking at the full GC log file:

382250 ParNew GCs are < 1 second
9303 are 100ms to 1 second
1267 are 1 second to 2 seconds
99 are 2 seconds to 10 seconds
24 are > 10 seconds, 48 seconds being the max

The long ones are somewhat bursty as you can see from looking at the line
numbers in the GC log:

$ egrep -n  '(ParNew.*real=[1-9][0-9]\)' gc.log.0

12300:2016-10-21T01:03:20.380+0000: 20278.069:
[GC2016-10-21T01:03:20.380+0000: 20278.070: [ParNew:
1697741K->10024K(1887488K), 16.9913450 secs]
33979542K->32817239K(84724992K), 16.9921050 secs] [Times: user=541.32
sys=14.37, real=16.99 secs]
43730:2016-10-21T14:12:25.050+0000: 67622.740:
[GC2016-10-21T14:12:25.051+0000: 67622.740: [ParNew:
1728194K->33817K(1887488K), 12.7508470 secs]
49737924K->48320707K(84724992K), 12.7517840 secs] [Times: user=405.89
sys=11.05, real=12.75 secs]
44079:2016-10-21T14:18:55.172+0000: 68012.862:
[GC2016-10-21T14:18:55.173+0000: 68012.862: [ParNew:
1698371K->26958K(1887488K), 12.7384460 secs]
50339815K->48930730K(84724992K), 12.7392360 secs] [Times: user=406.58
sys=11.29, real=12.73 secs]
50151:2016-10-21T17:10:14.471+0000: 78292.160:
[GC2016-10-21T17:10:14.471+0000: 78292.161: [ParNew:
1713813K->40968K(1887488K), 18.6593320 secs]
49366906K->47959129K(84724992K), 18.6602550 secs] [Times: user=590.03
sys=17.45, real=18.66 secs]
56073:2016-10-21T19:59:36.847+0000: 88454.536:
[GC2016-10-21T19:59:36.847+0000: 88454.537: [ParNew:
1685720K->20763K(1887488K), 16.0840200 secs]
50704025K->49302131K(84724992K), 16.0848810 secs] [Times: user=487.00
sys=16.84, real=16.09 secs]
78987:2016-10-22T05:49:25.623+0000: 123843.312:
[GC2016-10-22T05:49:25.623+0000: 123843.313: [ParNew:
1709771K->22678K(1887488K), 10.9933380 secs]
43323834K->41914203K(84724992K), 10.9943060 secs] [Times: user=349.67
sys=9.84, real=10.99 secs]
79104:2016-10-22T05:59:26.382+0000: 124444.071:
[GC2016-10-22T05:59:26.382+0000: 124444.072: [ParNew:
1697024K->22260K(1887488K), 11.5490390 secs]
44558499K->43145880K(84724992K), 11.5499650 secs] [Times: user=367.73
sys=10.01, real=11.55 secs]
79504:2016-10-22T06:09:36.983+0000: 125054.672:
[GC2016-10-22T06:09:36.984+0000: 125054.673: [ParNew:
1688112K->4769K(1887488K), 14.1528810 secs]
46684947K->45263748K(84724992K), 14.1539860 secs] [Times: user=452.28
sys=12.71, real=14.15 secs]
79772:2016-10-22T06:30:36.130+0000: 126313.819:
[GC2016-10-22T06:30:36.130+0000: 126313.820: [ParNew:
1725520K->35893K(1887488K), 14.4479670 secs]
48989739K->47563879K(84724992K), 14.4488810 secs] [Times: user=461.60
sys=13.04, real=14.45 secs]
80087:2016-10-22T06:37:07.202+0000: 126704.891:
[GC2016-10-22T06:37:07.202+0000: 126704.892: [ParNew:
1698021K->23440K(1887488K), 15.7039920 secs]
50517163K->49105987K(84724992K), 15.7050040 secs] [Times: user=497.65
sys=14.75, real=15.70 secs]
89969:2016-10-22T13:54:27.978+0000: 152945.667:
[GC2016-10-22T13:54:27.978+0000: 152945.668: [ParNew:
1834914K->15978K(1887488K), 11.5637150 secs]
48716340K->47307673K(84724992K), 11.5645440 secs] [Times: user=367.77
sys=10.01, real=11.57 secs]
90200:2016-10-22T14:05:02.717+0000: 153580.407:
[GC2016-10-22T14:05:02.718+0000: 153580.407: [ParNew:
1684626K->7078K(1887488K), 17.3424650 secs]
50361539K->48947648K(84724992K), 17.3433490 secs] [Times: user=554.39
sys=15.81, real=17.34 secs]
90299:2016-10-22T14:14:30.521+0000: 154148.210:
[GC2016-10-22T14:14:30.521+0000: 154148.211: [ParNew:
1690850K->6078K(1887488K), 13.1699350 secs]
51455784K->50033156K(84724992K), 13.1708900 secs] [Times: user=419.55
sys=11.54, real=13.17 secs]
261329:2016-10-26T00:06:44.499+0000: 448882.189:
[GC2016-10-26T00:06:44.500+0000: 448882.189: [ParNew:
1705614K->22224K(1887488K), 17.5831730 secs]
40683698K->39525817K(84724992K), 17.5843270 secs] [Times: user=561.85
sys=14.79, real=17.58 secs]
261935:2016-10-26T00:13:34.277+0000: 449291.967:
[GC2016-10-26T00:13:34.278+0000: 449291.967: [ParNew:
1690085K->26707K(1887488K), 13.9331790 secs]
43792178K->42655000K(84724992K), 13.9340780 secs] [Times: user=446.36
sys=11.45, real=13.93 secs]
262143:2016-10-26T00:20:09.397+0000: 449687.087:
[GC2016-10-26T00:20:09.398+0000: 449687.087: [ParNew:
1696593K->27078K(1887488K), 40.3344500 secs]
45588644K->44444949K(84724992K), 40.3355430 secs] [Times: user=1248.15
sys=43.07, real=40.33 secs]
262275:2016-10-26T00:27:02.196+0000: 450099.886:
[GC2016-10-26T00:27:02.197+0000: 450099.886: [ParNew:
1683406K->17853K(1887488K), 17.7472360 secs]
46908499K->45506131K(84724992K), 17.7482260 secs] [Times: user=567.03
sys=16.10, real=17.75 secs]
262282:2016-10-26T00:27:29.448+0000: 450127.138:
[GC2016-10-26T00:27:29.449+0000: 450127.138: [ParNew:
1687737K->10499K(1887488K), 35.4934000 secs]
47195678K->46044477K(84724992K), 35.4943230 secs] [Times: user=1131.34
sys=31.87, real=35.49 secs]
262631:2016-10-26T00:34:17.632+0000: 450535.321:
[GC2016-10-26T00:34:17.632+0000: 450535.321: [ParNew:
1687590K->10226K(1887488K), 21.4043600 secs]
49431427K->48018504K(84724992K), 21.4052230 secs] [Times: user=682.50
sys=19.46, real=21.41 secs]
262844:2016-10-26T00:41:08.118+0000: 450945.808:
[GC2016-10-26T00:41:08.119+0000: 450945.808: [ParNew:
1692928K->11302K(1887488K), 48.2899260 secs]
51073216K->49915878K(84724992K), 48.2909550 secs] [Times: user=1493.17
sys=53.55, real=48.28 secs]
345421:2016-10-27T04:17:59.617+0000: 550357.306:
[GC2016-10-27T04:17:59.618+0000: 550357.307: [ParNew:
1695052K->22991K(1887488K), 33.8707510 secs]
46334738K->45187822K(84724992K), 33.8718980 secs] [Times: user=1081.31
sys=30.59, real=33.86 secs]
345510:2016-10-27T04:24:11.721+0000: 550729.411:
[GC2016-10-27T04:24:11.722+0000: 550729.411: [ParNew:
1705080K->20401K(1887488K), 18.9795540 secs]
47388073K->45965537K(84724992K), 18.9805410 secs] [Times: user=606.94
sys=17.25, real=18.98 secs]
345514:2016-10-27T04:24:36.695+0000: 550754.385:
[GC2016-10-27T04:24:36.696+0000: 550754.385: [ParNew:
1707810K->32640K(1887488K), 30.9728200 secs]
47656489K->46506725K(84724992K), 30.9737300 secs] [Times: user=917.67
sys=33.07, real=30.97 secs]
345777:2016-10-27T04:31:30.102+0000: 551167.791:
[GC2016-10-27T04:31:30.102+0000: 551167.791: [ParNew:
1704518K->30860K(1887488K), 38.0976720 secs]
49570144K->48422333K(84724992K), 38.0984950 secs] [Times: user=1215.89
sys=34.79, real=38.09 secs]

Context around a single instance is fairly normal:

345773-2016-10-27T04:31:28.032+0000: 551165.721:
[GC2016-10-27T04:31:28.033+0000: 551165.722: [ParNew:
1685858K->8851K(1887488K), 0.0480250 secs] 49545909K->47870050K(84724992K),
0.0490200 secs] [Times: user=1.47 sys=0.02, real=0.05 secs]
345774-2016-10-27T04:31:28.635+0000: 551166.324:
[GC2016-10-27T04:31:28.636+0000: 551166.325: [ParNew:
1686675K->10456K(1887488K), 0.0463570 secs]
49547874K->47872545K(84724992K), 0.0473410 secs] [Times: user=1.41
sys=0.04, real=0.05 secs]
345775-2016-10-27T04:31:29.205+0000: 551166.894:
[GC2016-10-27T04:31:29.205+0000: 551166.894: [ParNew:
1688280K->12733K(1887488K), 0.0487100 secs]
49550369K->47876404K(84724992K), 0.0496310 secs] [Times: user=1.47
sys=0.04, real=0.05 secs]
345776-2016-10-27T04:31:29.798+0000: 551167.487:
[GC2016-10-27T04:31:29.798+0000: 551167.488: [ParNew:
1690557K->26694K(1887488K), 0.0471170 secs]
49554228K->47892320K(84724992K), 0.0481180 secs] [Times: user=1.40
sys=0.02, real=0.05 secs]
345777:2016-10-27T04:31:30.102+0000: 551167.791:
[GC2016-10-27T04:31:30.102+0000: 551167.791: [ParNew:
1704518K->30860K(1887488K), 38.0976720 secs]
49570144K->48422333K(84724992K), 38.0984950 secs] [Times: user=1215.89
sys=34.79, real=38.09 secs]
345778-2016-10-27T04:32:08.449+0000: 551206.139:
[GC2016-10-27T04:32:08.450+0000: 551206.139: [ParNew:
1708684K->122033K(1887488K), 0.0664280 secs]
50100157K->48528020K(84724992K), 0.0672860 secs] [Times: user=1.60
sys=0.05, real=0.07 secs]
345779-2016-10-27T04:32:09.090+0000: 551206.779:
[GC2016-10-27T04:32:09.091+0000: 551206.780: [ParNew:
1799857K->42169K(1887488K), 0.0688910 secs]
50205844K->48541030K(84724992K), 0.0696110 secs] [Times: user=1.70
sys=0.03, real=0.07 secs]
345780-2016-10-27T04:32:09.802+0000: 551207.491:
[GC2016-10-27T04:32:09.802+0000: 551207.491: [ParNew:
1719993K->43790K(1887488K), 0.0508540 secs]
50218854K->48542651K(84724992K), 0.0516000 secs] [Times: user=1.54
sys=0.03, real=0.05 secs]
345781-2016-10-27T04:32:10.536+0000: 551208.226:
[GC2016-10-27T04:32:10.537+0000: 551208.226: [ParNew:
1721614K->30389K(1887488K), 0.0668100 secs]
50220475K->48545932K(84724992K), 0.0675470 secs] [Times: user=1.81
sys=0.03, real=0.06 secs]
345782-2016-10-27T04:32:11.137+0000: 551208.826:
[GC2016-10-27T04:32:11.137+0000: 551208.826: [ParNew:
1708213K->18631K(1887488K), 0.0632570 secs]
50223756K->48540797K(84724992K), 0.0639650 secs] [Times: user=1.95
sys=0.01, real=0.06 secs]
345783-2016-10-27T04:32:11.642+0000: 551209.332:
[GC2016-10-27T04:32:11.643+0000: 551209.332: [ParNew:
1696455K->19415K(1887488K), 0.0509260 secs]
50218621K->48545033K(84724992K), 0.0516780 secs] [Times: user=1.55
sys=0.03, real=0.05 secs]

Since the user times are high as well, I don't think this could be swapping.

Here are the hard-earned set of JVM arguments that we're using:

-d64 -server -Xmx81g -Xms81g -XX:MaxNewSize=2g \
  -XX:NewSize=2g -XX:+UseConcMarkSweepGC -XX:+CMSConcurrentMTEnabled \
  -XX:+CMSParallelRemarkEnabled -XX:+CMSParallelSurvivorRemarkEnabled \
  -XX:+CMSScavengeBeforeRemark -XX:RefDiscoveryPolicy=1 \
  -XX:ParallelCMSThreads=12 -XX:CMSMaxAbortablePrecleanTime=3600000 \
  -XX:CMSInitiatingOccupancyFraction=60 -XX:+UseParNewGC
-XX:+UseBiasedLocking \
  -XX:MaxTenuringThreshold=2 -XX:+UseCompressedOops -XX:PermSize=256M \
  -XX:MaxPermSize=256M -XX:+HeapDumpOnOutOfMemoryError \
  -XX:+UseCMSInitiatingOccupancyOnly -XX:+UseMembar -XX:+UseLargePages \
  -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintCommandLineFlags \
  -XX:+UseGCLogFileRotation \
  -XX:NumberOfGCLogFiles=3 -XX:GCLogFileSize=100m \
  -Xloggc:${INSTANCE_ROOT}/logs/jvm/gc.log

This is on Linux with Java 1.7.0_72.

Does this look familiar to anyone? Alternatively, are there some more JVM
options that we could include to get more information?

One of the first things that we'll try is to move to a later JVM, but it
will be easier to get the customer to do that if we can point to a specific
issue that has been addressed.

Thanks for your help.

David
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.openjdk.java.net/pipermail/hotspot-gc-use/attachments/20161028/63b8764c/attachment.html>