Почему между двумя второстепенными сборщиками мусора ведется несколько журналов «Общее время, в течение которого потоки приложения были остановлены»

Я запускаю Java-приложение со следующими параметрами:

-Xms1G -Xmx2G -Xdebug -Xloggc: /usr/local/resin/log/gc.log -XX: + PrintGCDetails - XX: PermSize = 150M -XX: + PrintGCTimeStamps -XX: + PrintTenuringDistribution -XX: + PrintGCApplicationStoppedTime -XX: + PrintGCApplicationConcurrentTime -XX: + PrintHeapAtGC -XX: + UseConcMarkSweepGC

Я думал, что включение -XX: + PrintGCApplicationStoppedTime приведет к выводу, сколько времени приложение останавливается каждый раз, когда происходит сборщик мусора, но было несколько строк журналов, показывающих, сколько времени приложение останавливается между двумя второстепенными сборщиками мусора, например, в следующих журналах:

Total time for which application threads were stopped: 0.0043330 seconds
Application time: 1410.4236260 seconds
{Heap before GC invocations=636 (full 2):
 par new generation   total 38336K, used 34123K [0x00002aaab1a60000, 0x00002aaab43f0000, 0x00002aaab43f0000)
  eden space 34112K, 100% used [0x00002aaab1a60000, 0x00002aaab3bb0000, 0x00002aaab3bb0000)
  from space 4224K,   0% used [0x00002aaab3bb0000, 0x00002aaab3bb2de0, 0x00002aaab3fd0000)
  to   space 4224K,   0% used [0x00002aaab3fd0000, 0x00002aaab3fd0000, 0x00002aaab43f0000)
 concurrent mark-sweep generation total 1006016K, used 208278K [0x00002aaab43f0000, 0x00002aaaf1a60000, 0x00002aab31a60000)
 concurrent-mark-sweep perm gen total 153600K, used 90763K [0x00002aab31a60000, 0x00002aab3b060000, 0x00002aab3b060000)
122682.024: [GC 122682.024: [ParNew
Desired survivor size 2162688 bytes, new threshold 4 (max 4)
- age   1:       4896 bytes,       4896 total
- age   2:       2272 bytes,       7168 total
: 34123K->10K(38336K), 0.0037720 secs] 242402K->208291K(1044352K), 0.0038540 secs] [Times: user=0.00 sys=0.00, real=0.00 secs] 
Heap after GC invocations=637 (full 2):
 par new generation   total 38336K, used 10K [0x00002aaab1a60000, 0x00002aaab43f0000, 0x00002aaab43f0000)
  eden space 34112K,   0% used [0x00002aaab1a60000, 0x00002aaab1a60000, 0x00002aaab3bb0000)
  from space 4224K,   0% used [0x00002aaab3fd0000, 0x00002aaab3fd2bf8, 0x00002aaab43f0000)
  to   space 4224K,   0% used [0x00002aaab3bb0000, 0x00002aaab3bb0000, 0x00002aaab3fd0000)
 concurrent mark-sweep generation total 1006016K, used 208280K [0x00002aaab43f0000, 0x00002aaaf1a60000, 0x00002aab31a60000)
 concurrent-mark-sweep perm gen total 153600K, used 90763K [0x00002aab31a60000, 0x00002aab3b060000, 0x00002aab3b060000)
}
Total time for which application threads were stopped: 0.0044760 seconds
Application time: 317.6313600 seconds
Total time for which application threads were stopped: 0.0004960 seconds
Application time: 86.5483550 seconds
Total time for which application threads were stopped: 0.0005090 seconds
Application time: 0.0001400 seconds
Total time for which application threads were stopped: 0.0001360 seconds
Application time: 46.6827150 seconds
Total time for which application threads were stopped: 0.0004430 seconds
Application time: 74.2952540 seconds
Total time for which application threads were stopped: 0.0004940 seconds
Application time: 0.0001300 seconds
Total time for which application threads were stopped: 0.0001130 seconds
Application time: 0.0001290 seconds
Total time for which application threads were stopped: 0.0001290 seconds
Application time: 51.1991810 seconds
Total time for which application threads were stopped: 0.0004860 seconds
Application time: 190.7426760 seconds
Total time for which application threads were stopped: 0.0004930 seconds
Application time: 0.0000750 seconds
Total time for which application threads were stopped: 0.0001000 seconds
Application time: 55.4635280 seconds
Total time for which application threads were stopped: 0.0004900 seconds
Application time: 180.7308270 seconds
Total time for which application threads were stopped: 0.0005060 seconds
Application time: 60.9953830 seconds
Total time for which application threads were stopped: 0.0005490 seconds
Application time: 60.9591480 seconds
Total time for which application threads were stopped: 0.0006410 seconds
Application time: 292.0577720 seconds
{Heap before GC invocations=637 (full 2):
 par new generation   total 38336K, used 34122K [0x00002aaab1a60000, 0x00002aaab43f0000, 0x00002aaab43f0000)
  eden space 34112K, 100% used [0x00002aaab1a60000, 0x00002aaab3bb0000, 0x00002aaab3bb0000)
  from space 4224K,   0% used [0x00002aaab3fd0000, 0x00002aaab3fd2bf8, 0x00002aaab43f0000)
  to   space 4224K,   0% used [0x00002aaab3bb0000, 0x00002aaab3bb0000, 0x00002aaab3fd0000)
 concurrent mark-sweep generation total 1006016K, used 208280K [0x00002aaab43f0000, 0x00002aaaf1a60000, 0x00002aab31a60000)
 concurrent-mark-sweep perm gen total 153600K, used 90763K [0x00002aab31a60000, 0x00002aab3b060000, 0x00002aab3b060000)
124099.341: [GC 124099.341: [ParNew
Desired survivor size 2162688 bytes, new threshold 4 (max 4)
- age   1:      20680 bytes,      20680 total
- age   3:        808 bytes,      21488 total
: 34122K->25K(38336K), 0.0036900 secs] 242403K->208305K(1044352K), 0.0037700 secs] [Times: user=0.00 sys=0.00, real=0.01 secs] 
Heap after GC invocations=638 (full 2):
 par new generation   total 38336K, used 25K [0x00002aaab1a60000, 0x00002aaab43f0000, 0x00002aaab43f0000)
  eden space 34112K,   0% used [0x00002aaab1a60000, 0x00002aaab1a60000, 0x00002aaab3bb0000)
  from space 4224K,   0% used [0x00002aaab3bb0000, 0x00002aaab3bb6488, 0x00002aaab3fd0000)
  to   space 4224K,   0% used [0x00002aaab3fd0000, 0x00002aaab3fd0000, 0x00002aaab43f0000)
 concurrent mark-sweep generation total 1006016K, used 208280K [0x00002aaab43f0000, 0x00002aaaf1a60000, 0x00002aab31a60000)
 concurrent-mark-sweep perm gen total 153600K, used 90763K [0x00002aab31a60000, 0x00002aab3b060000, 0x00002aab3b060000)
}

Почему в журналах «Общее время, на которое потоки приложения были остановлены» и «Время приложения» несколько строк подряд между двумя второстепенными сборщиками мусора. С чем связана каждая из них? ГХ, который не выводится подробно? или они не вызваны сборщиком мусора?

Если я хочу узнать общее время, в течение которого мое приложение было остановлено во время сборки мусора, следует ли мне суммировать время во всех этих журналах?

10
задан user868872 29 July 2011 в 07:57
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