{"id":878,"date":"2020-06-29T15:32:56","date_gmt":"2020-06-29T07:32:56","guid":{"rendered":"https:\/\/www.zeroheart.xyz\/wordpress\/?p=878"},"modified":"2022-02-07T12:18:50","modified_gmt":"2022-02-07T04:18:50","slug":"gc%e7%9b%b8%e5%85%b3","status":"publish","type":"post","link":"https:\/\/www.zeroheart.xyz\/wordpress\/?p=878","title":{"rendered":"GC\u76f8\u5173"},"content":{"rendered":"\n
https:\/\/mp.weixin.qq.com\/s\/_AKQs-xXDHlk84HbwKUzOw <\/a>
https:\/\/mp.weixin.qq.com\/s\/P8s3kuceBNovUP5adXpFCQ<\/a>
\u8fd9\u4e24\u7bc7\u8bb2\u7684\u591f\u4e86\uff0c\u6211\u8fd9\u8fb9\u662f\u505a\u4e86\u4e9b\u6458\u5f55\uff0c\u8be6\u7ec6\u5185\u5bb9\u770b\u4e0a\u9762\u5f15\u7528\u7684\u94fe\u63a5\u3002<\/pre>\n\n\n\n
\u5806\u5b58\u653e\u5bf9\u8c61\u7684\u5b9e\u4f8b\u548c\u6570\u7ec4\uff0c\u662f\u8fdb\u884cGC\u7684\u533a\u57df\u3002<\/p>\n\n\n\n
\u5f15\u7528\u8ba1\u6570\u65b9\u6cd5\uff0c\u4f1a\u6709\u5faa\u73af\u5f15\u7528\u7684\u73b0\u8c61\uff0c\u4e0d\u80fd\u4f5c\u4e3aGC\u5bf9\u8c61\u7684\u6807\u8bb0\u3002\u73b0\u4ee3\u865a\u62df\u673a\u4f7f\u7528\u53ef\u8fbe\u6027\u7b97\u6cd5\u6765\u6807\u8bb0\u6e05\u7406\u7684\u5bf9\u8c61\u3002<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
a, b \u5bf9\u8c61\u53ef\u56de\u6536\uff0c\u5c31\u4e00\u5b9a\u4f1a\u88ab\u56de\u6536\u5417?\u5e76\u4e0d\u662f\uff0c\u5bf9\u8c61\u7684 finalize \u65b9\u6cd5\u7ed9\u4e86\u5bf9\u8c61\u4e00\u6b21\u5782\u6b7b\u6323\u624e\u7684\u673a\u4f1a\uff0c\u5f53\u5bf9\u8c61\u4e0d\u53ef\u8fbe\uff08\u53ef\u56de\u6536\uff09\u65f6\uff0c\u5f53\u53d1\u751fGC\u65f6\uff0c\u4f1a\u5148\u5224\u65ad\u5bf9\u8c61\u662f\u5426\u6267\u884c\u4e86 finalize \u65b9\u6cd5\uff0c\u5982\u679c\u672a\u6267\u884c\uff0c\u5219\u4f1a\u5148\u6267\u884c finalize \u65b9\u6cd5\uff0c\u6211\u4eec\u53ef\u4ee5\u5728\u6b64\u65b9\u6cd5\u91cc\u5c06\u5f53\u524d\u5bf9\u8c61\u4e0e GC Roots \u5173\u8054\uff0c\u8fd9\u6837\u6267\u884c finalize \u65b9\u6cd5\u4e4b\u540e\uff0cGC \u4f1a\u518d\u6b21\u5224\u65ad\u5bf9\u8c61\u662f\u5426\u53ef\u8fbe\uff0c\u5982\u679c\u4e0d\u53ef\u8fbe\uff0c\u5219\u4f1a\u88ab\u56de\u6536\uff0c\u5982\u679c\u53ef\u8fbe\uff0c\u5219\u4e0d\u56de\u6536\uff01
\u6ce8\u610f\uff1a<\/strong> finalize \u65b9\u6cd5\u53ea\u4f1a\u88ab\u6267\u884c\u4e00\u6b21\uff0c\u5982\u679c\u7b2c\u4e00\u6b21\u6267\u884c finalize \u65b9\u6cd5\u6b64\u5bf9\u8c61\u53d8\u6210\u4e86\u53ef\u8fbe\u786e\u5b9e\u4e0d\u4f1a\u56de\u6536\uff0c\u4f46\u5982\u679c\u5bf9\u8c61\u518d\u6b21\u88ab GC\uff0c\u5219\u4f1a\u5ffd\u7565 finalize \u65b9\u6cd5\uff0c\u5bf9\u8c61\u4f1a\u88ab\u56de\u6536\uff01\u8fd9\u4e00\u70b9\u5207\u8bb0!
\u90a3\u4e48\u8fd9\u4e9b GC Roots<\/strong> \u5230\u5e95\u662f\u4ec0\u4e48\u4e1c\u897f\u5462\uff0c\u54ea\u4e9b\u5bf9\u8c61\u53ef\u4ee5\u4f5c\u4e3a GC Root \u5462\uff0c\u6709\u4ee5\u4e0b\u51e0\u7c7b
1.\u865a\u62df\u673a\u6808\uff08\u6808\u5e27\u4e2d\u7684\u672c\u5730\u53d8\u91cf\u8868\uff09\u4e2d\u5f15\u7528\u7684\u5bf9\u8c61
2.\u65b9\u6cd5\u533a\u4e2d\u7c7b\u9759\u6001\u5c5e\u6027\u5f15\u7528\u7684\u5bf9\u8c61
3.\u65b9\u6cd5\u533a\u4e2d\u5e38\u91cf\u5f15\u7528\u7684\u5bf9\u8c61
4.\u672c\u5730\u65b9\u6cd5\u6808\u4e2d JNI\uff08\u5373\u4e00\u822c\u8bf4\u7684 Native \u65b9\u6cd5\uff09\u5f15\u7528\u7684\u5bf9\u8c61<\/pre>\n\n\n\n
finalize\u65b9\u6cd5\uff0c\u6211\u662f\u6ca1\u7528\u8fc7\u3002<\/p>\n\n\n\n
\u5783\u573e\u56de\u6536\u65b9\u6cd5<\/p>\n\n\n\n
\u6807\u8bb0-\u6e05\u9664\u3001\u6807\u8bb0-\u6574\u7406\u3001\u590d\u5236\u3001\u5206\u4ee3\uff08\u4ee5\u4e0a\u65b9\u6cd5\u7684\u6574\u5408\uff09<\/p>\n\n\n\n
\u5206\u4ee3\u7684\u5783\u573e\u56de\u6536\u65b9\u6cd5\u3001\u5206\u4e3a\u65b0\u751f\u4ee3\u3001\u8001\u5e74\u4ee3\u3002\u6bd4\u4f8b1:2\uff0c\u65b0\u751f\u4ee3\u5206\u4e3aEden\u533a\u3001s0\uff0cs1\uff0c\u6bd4\u4f8b\u662f8:1:1
Young GC\uff08\u4e5f\u53eb Minor GC\uff09
Old GC\uff08\u4e5f\u79f0\u4e3a Major GC\/Full GC\uff09

\u6bcf\u7ecf\u5386\u4e00\u6b21YG\uff0cage\u4f1a\u589e\u52a01\uff0c\u5982\u679c\u4e00\u76f4\u6ca1\u56de\u6536\uff0cage=15\u4f1a\u8fdbold\u533a
\u53e6\u5916\u5927\u5bf9\u8c61\uff0c\u6216\u8005s\u4e2d\u5e74\u9f84\u4e00\u6837\u7684\u5bf9\u8c61\u5927\u4e8e1\u534a\uff0c\u90a3\u4e48\u5e74\u9f84\u5927\u4e8e\u7b49\u4e8e\u5b83\u7684\uff0c\u4f1a\u8fdb\u5165\u8001\u5e74\u4ee3\u3002

\u7a7a\u95f4\u5206\u914d\u62c5\u4fdd<\/strong>
\u5728\u53d1\u751f MinorGC \u4e4b\u524d\uff0c\u865a\u62df\u673a\u4f1a\u5148\u68c0\u67e5\u8001\u5e74\u4ee3\u6700\u5927\u53ef\u7528\u7684\u8fde\u7eed\u7a7a\u95f4\u662f\u5426\u5927\u4e8e\u65b0\u751f\u4ee3\u6240\u6709\u5bf9\u8c61\u7684\u603b\u7a7a\u95f4\uff0c\u5982\u679c\u5927\u4e8e\uff0c\u90a3\u4e48Minor GC \u53ef\u4ee5\u786e\u4fdd\u662f\u5b89\u5168\u7684,\u5982\u679c\u4e0d\u5927\u4e8e\uff0c\u90a3\u4e48\u865a\u62df\u673a\u4f1a\u67e5\u770b HandlePromotionFailure \u8bbe\u7f6e\u503c\u662f\u5426\u5141\u8bb8\u62c5\u4fdd\u5931\u8d25\u3002\u5982\u679c\u5141\u8bb8\uff0c\u90a3\u4e48\u4f1a\u7ee7\u7eed\u68c0\u67e5\u8001\u5e74\u4ee3\u6700\u5927\u53ef\u7528\u8fde\u7eed\u7a7a\u95f4\u662f\u5426\u5927\u4e8e\u5386\u6b21\u664b\u5347\u5230\u8001\u5e74\u4ee3\u5bf9\u8c61\u7684\u5e73\u5747\u5927\u5c0f\uff0c\u5982\u679c\u5927\u4e8e\u5219\u8fdb\u884c Minor GC\uff0c\u5426\u5219\u53ef\u80fd\u8fdb\u884c\u4e00\u6b21 Full GC\u3002

\u5982\u679c\u8001\u5e74\u4ee3\u6ee1\u4e86\uff0c\u4f1a\u89e6\u53d1 Full GC, Full GC \u4f1a\u540c\u65f6\u56de\u6536\u65b0\u751f\u4ee3\u548c\u8001\u5e74\u4ee3\uff08\u5373\u5bf9\u6574\u4e2a\u5806\u8fdb\u884cGC\uff09\uff0c\u5b83\u4f1a\u5bfc\u81f4 Stop The World\uff08\u7b80\u79f0 STW\uff09,\u9020\u6210\u633a\u5927\u7684\u6027\u80fd\u5f00\u9500\u3002
\u4ec0\u4e48\u662f STW \uff1f\u6240\u8c13\u7684 STW, \u5373\u5728 GC\uff08minor GC \u6216 Full GC\uff09\u671f\u95f4\uff0c\u53ea\u6709\u5783\u573e\u56de\u6536\u5668\u7ebf\u7a0b\u5728\u5de5\u4f5c\uff0c\u5176\u4ed6\u5de5\u4f5c\u7ebf\u7a0b\u5219\u88ab\u6302\u8d77\u3002

Minor GC \u4e5f\u4f1a\u9020\u6210 STW,\u4f46\u53ea\u4f1a\u89e6\u53d1\u8f7b\u5fae\u7684 STW

<\/pre>\n\n\n\n
\u5f53\u664b\u5347\u5230\u8001\u5e74\u4ee3\u7684\u5bf9\u8c61\u5927\u4e8e\u4e86\u8001\u5e74\u4ee3\u7684\u5269\u4f59\u7a7a\u95f4\u65f6\uff0c\u5c31\u4f1a\u89e6\u53d1FGC\uff08Major GC\uff09\uff0cFGC\u5904\u7406\u7684\u533a\u57df\u540c\u65f6\u5305\u62ec\u65b0\u751f\u4ee3\u548c\u8001\u5e74\u4ee3\u3002\u9664\u6b64\u4e4b\u5916\uff0c\u8fd8\u6709\u4ee5\u4e0b4\u79cd\u60c5\u51b5\u4e5f\u4f1a\u89e6\u53d1FGC\uff1a

1.\u8001\u5e74\u4ee3\u7684\u5185\u5b58\u4f7f\u7528\u7387\u8fbe\u5230\u4e86\u4e00\u5b9a\u9608\u503c\uff08\u53ef\u901a\u8fc7\u53c2\u6570\u8c03\u6574\uff09\uff0c\u76f4\u63a5\u89e6\u53d1FGC\u3002
2.\u7a7a\u95f4\u5206\u914d\u62c5\u4fdd\uff1a\u5728YGC\u4e4b\u524d\uff0c\u4f1a\u5148\u68c0\u67e5\u8001\u5e74\u4ee3\u6700\u5927\u53ef\u7528\u7684\u8fde\u7eed\u7a7a\u95f4\u662f\u5426\u5927\u4e8e\u65b0\u751f\u4ee3\u6240\u6709\u5bf9\u8c61\u7684\u603b\u7a7a\u95f4\u3002\u5982\u679c\u5c0f\u4e8e\uff0c\u8bf4\u660eYGC\u662f\u4e0d\u5b89\u5168\u7684\uff0c\u5219\u4f1a\u67e5\u770b\u53c2\u6570 HandlePromotionFailure \u662f\u5426\u88ab\u8bbe\u7f6e\u6210\u4e86\u5141\u8bb8\u62c5\u4fdd\u5931\u8d25\uff0c\u5982\u679c\u4e0d\u5141\u8bb8\u5219\u76f4\u63a5\u89e6\u53d1Full GC\uff1b\u5982\u679c\u5141\u8bb8\uff0c\u90a3\u4e48\u4f1a\u8fdb\u4e00\u6b65\u68c0\u67e5\u8001\u5e74\u4ee3\u6700\u5927\u53ef\u7528\u7684\u8fde\u7eed\u7a7a\u95f4\u662f\u5426\u5927\u4e8e\u5386\u6b21\u664b\u5347\u5230\u8001\u5e74\u4ee3\u5bf9\u8c61\u7684\u5e73\u5747\u5927\u5c0f\uff0c\u5982\u679c\u5c0f\u4e8e\u4e5f\u4f1a\u89e6\u53d1 Full GC\u3002
3.Metaspace\uff08\u5143\u7a7a\u95f4\uff09\u5728\u7a7a\u95f4\u4e0d\u8db3\u65f6\u4f1a\u8fdb\u884c\u6269\u5bb9\uff0c\u5f53\u6269\u5bb9\u5230\u4e86-XX:MetaspaceSize \u53c2\u6570\u7684\u6307\u5b9a\u503c\u65f6\uff0c\u4e5f\u4f1a\u89e6\u53d1FGC\u3002
4.System.gc() \u6216\u8005Runtime.gc() \u88ab\u663e\u5f0f\u8c03\u7528\u65f6\uff0c\u89e6\u53d1FGC\u3002

FGC\u8fc7\u4e8e\u9891\u7e41\u3001YGC\u8017\u65f6\u8fc7\u957f\u662f\u6bd4\u8f83\u5178\u578b\u7684GC\u95ee\u9898\uff0c\u5f71\u54cd\u7a0b\u5e8f\u54cd\u5e94\uff0c\u9700\u8981\u7279\u522b\u5173\u6ce8\uff0cFGC\u8017\u65f6\u8fc7\u957f\u3001YGC\u8fc7\u4e8e\u9891\u7e41\u4e24\u79cd\u60c5\u51b5\u7684\u4e25\u91cd\u7a0b\u5ea6\u4f4e\u4e00\u4e9b\uff0c\u4f46\u662f\u5bf9\u4e8e\u9ad8\u5e76\u53d1\u6216\u8005\u9ad8\u53ef\u7528\u7684\u7a0b\u5e8f\u4e5f\u9700\u8981\u5173\u6ce8\u3002


1. \u6e05\u695a\u4ece\u7a0b\u5e8f\u89d2\u5ea6\uff0c\u6709\u54ea\u4e9b\u539f\u56e0\u5bfc\u81f4FGC\uff1f <\/strong>
\u5927\u5bf9\u8c61\uff1a\u7cfb\u7edf\u4e00\u6b21\u6027\u52a0\u8f7d\u4e86\u8fc7\u591a\u6570\u636e\u5230\u5185\u5b58\u4e2d\uff08\u6bd4\u5982SQL\u67e5\u8be2\u672a\u505a\u5206\u9875\uff09\uff0c\u5bfc\u81f4\u5927\u5bf9\u8c61\u8fdb\u5165\u4e86\u8001\u5e74\u4ee3\u3002

\u5185\u5b58\u6cc4\u6f0f\uff1a\u9891\u7e41\u521b\u5efa\u4e86\u5927\u91cf\u5bf9\u8c61\uff0c\u4f46\u662f\u65e0\u6cd5\u88ab\u56de\u6536\uff08\u6bd4\u5982IO\u5bf9\u8c61\u4f7f\u7528\u5b8c\u540e\u672a\u8c03\u7528close\u65b9\u6cd5\u91ca\u653e\u8d44\u6e90\uff09\uff0c\u5148\u5f15\u53d1FGC\uff0c\u6700\u540e\u5bfc\u81f4OOM.

\u7a0b\u5e8f\u9891\u7e41\u751f\u6210\u4e00\u4e9b\u957f\u751f\u547d\u5468\u671f\u7684\u5bf9\u8c61\uff0c\u5f53\u8fd9\u4e9b\u5bf9\u8c61\u7684\u5b58\u6d3b\u5e74\u9f84\u8d85\u8fc7\u5206\u4ee3\u5e74\u9f84\u65f6\u4fbf\u4f1a\u8fdb\u5165\u8001\u5e74\u4ee3\uff0c\u6700\u540e\u5f15\u53d1FGC.

\u7a0b\u5e8fBUG\u5bfc\u81f4\u52a8\u6001\u751f\u6210\u4e86\u5f88\u591a\u65b0\u7c7b\uff0c\u4f7f\u5f97 Metaspace \u4e0d\u65ad\u88ab\u5360\u7528\uff0c\u5148\u5f15\u53d1FGC\uff0c\u6700\u540e\u5bfc\u81f4OOM.

\u4ee3\u7801\u4e2d\u663e\u5f0f\u8c03\u7528\u4e86gc\u65b9\u6cd5\uff0c\u5305\u62ec\u81ea\u5df1\u7684\u4ee3\u7801\u751a\u81f3\u6846\u67b6\u4e2d\u7684\u4ee3\u7801\u3002

JVM\u53c2\u6570\u8bbe\u7f6e\u95ee\u9898\uff1a\u5305\u62ec\u603b\u5185\u5b58\u5927\u5c0f\u3001\u65b0\u751f\u4ee3\u548c\u8001\u5e74\u4ee3\u7684\u5927\u5c0f\u3001Eden\u533a\u548cS\u533a\u7684\u5927\u5c0f\u3001\u5143\u7a7a\u95f4\u5927\u5c0f\u3001\u5783\u573e\u56de\u6536\u7b97\u6cd5\u7b49\u7b49\u3002

2. \u6e05\u695a\u6392\u67e5\u95ee\u9898\u65f6\u80fd\u4f7f\u7528\u54ea\u4e9b\u5de5\u5177<\/strong>
\u516c\u53f8\u7684\u76d1\u63a7\u7cfb\u7edf\uff1a\u5927\u90e8\u5206\u516c\u53f8\u90fd\u4f1a\u6709\uff0c\u53ef\u5168\u65b9\u4f4d\u76d1\u63a7JVM\u7684\u5404\u9879\u6307\u6807\u3002
JDK\u7684\u81ea\u5e26\u5de5\u5177\uff0c\u5305\u62ecjmap\u3001jstat\u7b49\u5e38\u7528\u547d\u4ee4\uff1a
# \u67e5\u770b\u5806\u5185\u5b58\u5404\u533a\u57df\u7684\u4f7f\u7528\u7387\u4ee5\u53caGC\u60c5\u51b5
jstat -gcutil -h20 pid 1000\uff0c\u6548\u679c\u5982\u4e0b\u56fe
# \u67e5\u770b\u5806\u5185\u5b58\u4e2d\u7684\u5b58\u6d3b\u5bf9\u8c61\uff0c\u5e76\u6309\u7a7a\u95f4\u6392\u5e8f
jmap -histo pid | head -n20
# dump\u5806\u5185\u5b58\u6587\u4ef6
jmap -dump:format=b,file=heap pid
\u53ef\u89c6\u5316\u7684\u5806\u5185\u5b58\u5206\u6790\u5de5\u5177\uff1aJVisualVM\u3001MAT\u7b49
-XX:+HeapDumpOnOutOfMemoryError \u53ef\u4ee5\u914d\u7f6e\u53d1\u751fOOM\u65f6\u5019\u81ea\u52a8dump\uff0c\u540e\u7eed\u518d\u5206\u6790\u3002

3. \u6392\u67e5\u6307\u5357<\/strong>
\u67e5\u770b\u76d1\u63a7\uff0c\u4ee5\u4e86\u89e3\u51fa\u73b0\u95ee\u9898\u7684\u65f6\u95f4\u70b9\u4ee5\u53ca\u5f53\u524dFGC\u7684\u9891\u7387\uff08\u53ef\u5bf9\u6bd4\u6b63\u5e38\u60c5\u51b5\u770b\u9891\u7387\u662f\u5426\u6b63\u5e38\uff09

\u4e86\u89e3\u8be5\u65f6\u95f4\u70b9\u4e4b\u524d\u6709\u6ca1\u6709\u7a0b\u5e8f\u4e0a\u7ebf\u3001\u57fa\u7840\u7ec4\u4ef6\u5347\u7ea7\u7b49\u60c5\u51b5\u3002

\u4e86\u89e3JVM\u7684\u53c2\u6570\u8bbe\u7f6e\uff0c\u5305\u62ec\uff1a\u5806\u7a7a\u95f4\u5404\u4e2a\u533a\u57df\u7684\u5927\u5c0f\u8bbe\u7f6e\uff0c\u65b0\u751f\u4ee3\u548c\u8001\u5e74\u4ee3\u5206\u522b\u91c7\u7528\u4e86\u54ea\u4e9b\u5783\u573e\u6536\u96c6\u5668\uff0c\u7136\u540e\u5206\u6790JVM\u53c2\u6570\u8bbe\u7f6e\u662f\u5426\u5408\u7406\u3002

\u518d\u5bf9\u6b65\u9aa41\u4e2d\u5217\u51fa\u7684\u53ef\u80fd\u539f\u56e0\u505a\u6392\u9664\u6cd5\uff0c\u5176\u4e2d\u5143\u7a7a\u95f4\u88ab\u6253\u6ee1\u3001\u5185\u5b58\u6cc4\u6f0f\u3001\u4ee3\u7801\u663e\u5f0f\u8c03\u7528gc\u65b9\u6cd5\u6bd4\u8f83\u5bb9\u6613\u6392\u67e5\u3002

\u9488\u5bf9\u5927\u5bf9\u8c61\u6216\u8005\u957f\u751f\u547d\u5468\u671f\u5bf9\u8c61\u5bfc\u81f4\u7684FGC\uff0c\u53ef\u901a\u8fc7 jmap -histo \u547d\u4ee4\u5e76\u7ed3\u5408dump\u5806\u5185\u5b58\u6587\u4ef6\u4f5c\u8fdb\u4e00\u6b65\u5206\u6790\uff0c\u9700\u8981\u5148\u5b9a\u4f4d\u5230\u53ef\u7591\u5bf9\u8c61\u3002

\u901a\u8fc7\u53ef\u7591\u5bf9\u8c61\u5b9a\u4f4d\u5230\u5177\u4f53\u4ee3\u7801\u518d\u6b21\u5206\u6790\uff0c\u8fd9\u65f6\u5019\u8981\u7ed3\u5408GC\u539f\u7406\u548cJVM\u53c2\u6570\u8bbe\u7f6e\uff0c\u5f04\u6e05\u695a\u53ef\u7591\u5bf9\u8c61\u662f\u5426\u6ee1\u8db3\u4e86\u8fdb\u5165\u5230\u8001\u5e74\u4ee3\u7684\u6761\u4ef6\u624d\u80fd\u4e0b\u7ed3\u8bba\u3002
<\/pre>\n\n\n\n
\"\"<\/figure>\n\n\n\n
cpu\u9ad8\u7684\u6392\u67e5
top -c \u5217\u51fa\u8fdb\u7a0b\uff0c\u6309P\uff0c\u6309\u7167cpu\u4f7f\u7528\u7387\u6392\u5e8f
top -Hp pid\uff0c\u5217\u51fa\u7ebf\u7a0btid \u6216\u8005 ps -mp pid -o THREAD,tid,time 
printf \"%x\\n\" tid => \u5047\u8bbe\u662fb26
jstack -l pid > .\/pid.stack
cat 2609.stack | grep 'b26' -C 8
\u518d\u5206\u6790\uff0c\u5982\u679c\u662fgc\u4ee3\u7801\u4e00\u76f4\u8fd0\u884c\uff0c\u90a3\u5c31\u68c0\u67e5GC\u76f8\u5173\u95ee\u9898\uff0c\u5982\u679c\u662f\u81ea\u5df1\u5199\u7684\u4ee3\u7801\u95ee\u9898\uff0c\u90a3\u5c31\u68c0\u67e5\u6b7b\u5faa\u73af\u4e4b\u7c7b\u7684\u3002

\u53ef\u4ee5\u76f4\u63a5\u5229\u7528\u8fd9\u4e2a\u811a\u672c\uff0c\u4e00\u952e\u6253\u5370cpu\u5360\u7528\u9ad8\u7684\u7ebf\u7a0b
https:\/\/github.com\/oldratlee\/useful-scripts\/blob\/master\/docs\/java.md#-show-busy-java-threads<\/a>

\u2022  \u6b7b\u9501\uff0cDeadlock\uff08\u91cd\u70b9\u5173\u6ce8\uff09 
\u2022  \u7b49\u5f85\u8d44\u6e90\uff0cWaiting on condition\uff08\u91cd\u70b9\u5173\u6ce8\uff09 
\u2022  \u7b49\u5f85\u83b7\u53d6\u76d1\u89c6\u5668\uff0cWaiting on monitor entry\uff08\u91cd\u70b9\u5173\u6ce8\uff09 
\u2022  \u963b\u585e\uff0cBlocked\uff08\u91cd\u70b9\u5173\u6ce8\uff09 
\u2022  \u6267\u884c\u4e2d\uff0cRunnable 
\u2022  \u6682\u505c\uff0cSuspended 
\u2022  \u5bf9\u8c61\u7b49\u5f85\u4e2d\uff0cObject.wait() \u6216 TIMED_WAITING 
\u2022  \u505c\u6b62\uff0cParked 


<\/pre>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\"\"<\/figure>\n\n\n\n
cms\uff0c\u5e76\u53d1\u6807\u8bb0\u6e05\u9664\uff0c\u901f\u5ea6\u6700\u5feb\uff0c\u4f46\u662f\u6709\u788e\u7247\uff0c\u662fG1\u4e4b\u524d\u7684\u9996\u9009<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\"\"<\/figure>\n\n\n\n
G1\u53ef\u4ee5\u8bbe\u7f6e\u7528\u6237\u671f\u671b\u7684stw\u65f6\u95f4(jvm\u5c3d\u91cf\u4fdd\u8bc1)<\/p>\n\n\n\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
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