occasional ParNew times of 15+ seconds

Sat Oct 29 13:40:02 UTC 2016

Thank you for the response. Yes. meminfo (see full output below) shows
~80GB of AnonHugePages, which is pretty close to the size of the JVM (full
output below). Looking back through previous information that we have from
this customer, transparent huge pages have been turned on for years. We've
asked them for anything else that might have changed in this environment.

Are there any other JVM options that we could enable that would shed light
on what's going on within the ParNew? Would -XX:+PrintTLAB
-XX:+PrintPLAB -XX:PrintFLSStatistics=1
show anything useful?

David

MemTotal:       264396572 kB
MemFree:         2401576 kB
Buffers:          381564 kB
Cached:         172673120 kB
SwapCached:            0 kB
Active:         163439836 kB
Inactive:       90737452 kB
Active(anon):   76910848 kB
Inactive(anon):  4212580 kB
Active(file):   86528988 kB
Inactive(file): 86524872 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:      16236540 kB
SwapFree:       16236540 kB
Dirty:             14552 kB
Writeback:             0 kB
AnonPages:      81111768 kB
Mapped:            31312 kB
Shmem:               212 kB
Slab:            6078732 kB
SReclaimable:    5956052 kB
SUnreclaim:       122680 kB
KernelStack:       41296 kB
PageTables:       171324 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:    148434824 kB
Committed_AS:   93124984 kB
VmallocTotal:   34359738367 kB
VmallocUsed:      686780 kB
VmallocChunk:   34225639420 kB
HardwareCorrupted:     0 kB
*AnonHugePages:  80519168 kB*
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
DirectMap4k:        5132 kB
DirectMap2M:     1957888 kB
DirectMap1G:    266338304 kB

On Fri, Oct 28, 2016 at 8:04 PM, Vitaly Davidovich <vitalyd at gmail.com>
wrote:

>
>
> On Friday, October 28, 2016, David Ely <david.ely at unboundid.com> wrote:
>
>> 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.
>>
> Can you ask the customer if they're using transparent hugepages (THP)?
>
>>
>> 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
>>
>
>
> --
> Sent from my phone
>
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