了解 GC 日志 - 应用程序线程已停止

Question

查看 GC 日志文件，不言自明地了解应用已停止 0.0011450 秒（stop-the-world）

Total time for which application threads were stopped: 0.0011450 seconds

但是，请帮我理解下面几行是否也意味着停止世界？或者它只是显示每个线程所花费的时间，real=TIME 是什么意思（下面最后一行）？

Finished work stealing in 3th thread: 13.706 sec
Finished work stealing in 2th thread: 17.325 sec
Finished work stealing in 4th thread: 17.052 sec
Finished work stealing in 0th thread: 17.325 sec
Finished work stealing in 1th thread: 17.324 sec
2015-08-19T03:20:32.882-0400: 321985.669: [CMS-concurrent-mark: 20.519/20.624 secs] (CMS-concurrent-mark yielded 6 times)
 [Times: user=138.91 sys=0.10, real=20.62 secs]

Answer 1

This oracle blog post 是谷歌搜索 "CMS-concurrent-mark" 时的第一个结果，并解释了 CMS 的各个阶段。

运行通过 GCviewer 的日志也会分别列出 STW 和非 STW 阶段。

并且由于您已经打开了应用程序停止时间日志记录，因此无论是否是 STW 暂停，缺少停止时间日志记录条目都应该是一个死的赠品。

what does real=TIME means (last line below)?

此输出等同于您从 time for example. Also see this SO answer. Or this one 获得的输出，特别是 CMS 日志。

了解 GC 日志 - 应用程序线程已停止

Understanding GC logs - app thread were stopped

java

multithreading

garbage-collection

garbage