{"id":4656,"date":"2020-01-15T10:27:39","date_gmt":"2020-01-15T02:27:39","guid":{"rendered":"https:\/\/www.xttblog.com\/?p=4656"},"modified":"2020-01-15T10:27:39","modified_gmt":"2020-01-15T02:27:39","slug":"cpu%e9%a3%99%e9%ab%98%ef%bc%8c%e9%a2%91%e7%b9%81gc%ef%bc%8c%e6%80%8e%e4%b9%88%e6%8e%92%e6%9f%a5%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/www.xttblog.com\/?p=4656","title":{"rendered":"CPU\u98d9\u9ad8\uff0c\u9891\u7e41GC\uff0c\u600e\u4e48\u6392\u67e5\uff1f"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u5904\u7406\u8fc7\u7ebf\u4e0a\u95ee\u9898\u7684\u540c\u5b66\u57fa\u672c\u4e0a\u90fd\u4f1a\u9047\u5230\u7cfb\u7edf\u7a81\u7136\u8fd0\u884c\u7f13\u6162\uff0cCPU 100%\uff0c\u4ee5\u53caFull GC\u6b21\u6570\u8fc7\u591a\u7684\u95ee\u9898\u3002\u5f53\u7136\uff0c\u8fd9\u4e9b\u95ee\u9898\u7684\u6700\u7ec8\u5bfc\u81f4\u7684\u76f4\u89c2\u73b0\u8c61\u5c31\u662f\u7cfb\u7edf\u8fd0\u884c\u7f13\u6162\uff0c\u5e76\u4e14\u6709\u5927\u91cf\u7684\u62a5\u8b66\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u672c\u6587\u4e3b\u8981\u9488\u5bf9\u7cfb\u7edf\u8fd0\u884c\u7f13\u6162\u8fd9\u4e00\u95ee\u9898\uff0c\u63d0\u4f9b\u8be5\u95ee\u9898\u7684\u6392\u67e5\u601d\u8def\uff0c\u4ece\u800c\u5b9a\u4f4d\u51fa\u95ee\u9898\u7684\u4ee3\u7801\u70b9\uff0c\u8fdb\u800c\u63d0\u4f9b\u89e3\u51b3\u8be5\u95ee\u9898\u7684\u601d\u8def\u3002<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img decoding=\"async\" src=\"https:\/\/raw.githubusercontent.com\/xmt1139057136\/xttblog\/master\/WX20200115-100223%402x.png\" alt=\"\" \/><figcaption>CPU\u98d9\u9ad8\uff0c\u9891\u7e41GC\uff0c\u600e\u4e48\u6392\u67e5\uff1f<\/figcaption><\/figure><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">\u5bf9\u4e8e\u7ebf\u4e0a\u7cfb\u7edf\u7a81\u7136\u4ea7\u751f\u7684\u8fd0\u884c\u7f13\u6162\u95ee\u9898\uff0c\u5982\u679c\u8be5\u95ee\u9898\u5bfc\u81f4\u7ebf\u4e0a\u7cfb\u7edf\u4e0d\u53ef\u7528\uff0c\u90a3\u4e48\u9996\u5148\u9700\u8981\u505a\u7684\u5c31\u662f\uff0c\u5bfc\u51fajstack\u548c\u5185\u5b58\u4fe1\u606f\uff0c\u7136\u540e\u91cd\u542f\u7cfb\u7edf\uff0c\u5c3d\u5feb\u4fdd\u8bc1\u7cfb\u7edf\u7684\u53ef\u7528\u6027\u3002\u8fd9\u79cd\u60c5\u51b5\u53ef\u80fd\u7684\u539f\u56e0\u4e3b\u8981\u6709\u4e24\u79cd\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u4ee3\u7801\u4e2d\u67d0\u4e2a\u4f4d\u7f6e\u8bfb\u53d6\u6570\u636e\u91cf\u8f83\u5927\uff0c\u5bfc\u81f4\u7cfb\u7edf\u5185\u5b58\u8017\u5c3d\uff0c\u4ece\u800c\u5bfc\u81f4Full GC\u6b21\u6570\u8fc7\u591a\uff0c\u7cfb\u7edf\u7f13\u6162\uff1b<\/li><li>\u4ee3\u7801\u4e2d\u6709\u6bd4\u8f83\u8017CPU\u7684\u64cd\u4f5c\uff0c\u5bfc\u81f4CPU\u8fc7\u9ad8\uff0c\u7cfb\u7edf\u8fd0\u884c\u7f13\u6162\uff1b<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u76f8\u5bf9\u6765\u8bf4\uff0c\u8fd9\u662f\u51fa\u73b0\u9891\u7387\u6700\u9ad8\u7684\u4e24\u79cd\u7ebf\u4e0a\u95ee\u9898\uff0c\u800c\u4e14\u5b83\u4eec\u4f1a\u76f4\u63a5\u5bfc\u81f4\u7cfb\u7edf\u4e0d\u53ef\u7528\u3002\u53e6\u5916\u6709\u51e0\u79cd\u60c5\u51b5\u4e5f\u4f1a\u5bfc\u81f4\u67d0\u4e2a\u529f\u80fd\u8fd0\u884c\u7f13\u6162\uff0c\u4f46\u662f\u4e0d\u81f3\u4e8e\u5bfc\u81f4\u7cfb\u7edf\u4e0d\u53ef\u7528\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u4ee3\u7801\u67d0\u4e2a\u4f4d\u7f6e\u6709\u963b\u585e\u6027\u7684\u64cd\u4f5c\uff0c\u5bfc\u81f4\u8be5\u529f\u80fd\u8c03\u7528\u6574\u4f53\u6bd4\u8f83\u8017\u65f6\uff0c\u4f46\u51fa\u73b0\u662f\u6bd4\u8f83\u968f\u673a\u7684\uff1b<\/li><li>\u67d0\u4e2a\u7ebf\u7a0b\u7531\u4e8e\u67d0\u79cd\u539f\u56e0\u800c\u8fdb\u5165WAITING\u72b6\u6001\uff0c\u6b64\u65f6\u8be5\u529f\u80fd\u6574\u4f53\u4e0d\u53ef\u7528\uff0c\u4f46\u662f\u65e0\u6cd5\u590d\u73b0\uff1b<\/li><li>\u7531\u4e8e\u9501\u4f7f\u7528\u4e0d\u5f53\uff0c\u5bfc\u81f4\u591a\u4e2a\u7ebf\u7a0b\u8fdb\u5165\u6b7b\u9501\u72b6\u6001\uff0c\u4ece\u800c\u5bfc\u81f4\u7cfb\u7edf\u6574\u4f53\u6bd4\u8f83\u7f13\u6162\u3002<\/li><\/ul>\n\n\n\n<h2>Full GC\u6b21\u6570\u8fc7\u591a<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u76f8\u5bf9\u6765\u8bf4\uff0c\u8fd9\u79cd\u60c5\u51b5\u662f\u6700\u5bb9\u6613\u51fa\u73b0\u7684\uff0c\u5c24\u5176\u662f\u65b0\u529f\u80fd\u4e0a\u7ebf\u65f6\u3002\u5bf9\u4e8eFull GC\u8f83\u591a\u7684\u60c5\u51b5\uff0c\u5176\u4e3b\u8981\u6709\u5982\u4e0b\u4e24\u4e2a\u7279\u5f81\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u7ebf\u4e0a\u591a\u4e2a\u7ebf\u7a0b\u7684CPU\u90fd\u8d85\u8fc7\u4e86100%\uff0c\u901a\u8fc7jstack\u547d\u4ee4\u53ef\u4ee5\u770b\u5230\u8fd9\u4e9b\u7ebf\u7a0b\u4e3b\u8981\u662f\u5783\u573e\u56de\u6536\u7ebf\u7a0b<\/li><li>\u901a\u8fc7jstat\u547d\u4ee4\u76d1\u63a7GC\u60c5\u51b5\uff0c\u53ef\u4ee5\u770b\u5230Full GC\u6b21\u6570\u975e\u5e38\u591a\uff0c\u5e76\u4e14\u6b21\u6570\u5728\u4e0d\u65ad\u589e\u52a0\u3002<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u9996\u5148\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528top\u547d\u4ee4\u67e5\u770b\u7cfb\u7edfCPU\u7684\u5360\u7528\u60c5\u51b5\uff0c\u5982\u4e0b\u662f\u7cfb\u7edfCPU\u8f83\u9ad8\u7684\u4e00\u4e2a\u793a\u4f8b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>top - 08:31:10 up 30 min,  0 users,  load average: 0.73, 0.58, 0.34\nKiB Mem:   2046460 total,  1923864 used,   122596 free,    14388 buffers\nKiB Swap:  1048572 total,        0 used,  1048572 free.  1192352 cached Mem\n\n  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND\n    9 root      20   0 2557160 288976  15812 S  98.0 14.1   0:42.60 java<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u53ef\u4ee5\u770b\u5230\uff0c\u6709\u4e00\u4e2aJava\u7a0b\u5e8f\u6b64\u65f6CPU\u5360\u7528\u91cf\u8fbe\u5230\u4e8698.8%\uff0c\u6b64\u65f6\u6211\u4eec\u53ef\u4ee5\u590d\u5236\u8be5\u8fdb\u7a0bid9\uff0c\u5e76\u4e14\u4f7f\u7528\u5982\u4e0b\u547d\u4ee4\u67e5\u770b\u5462\u8be5\u8fdb\u7a0b\u7684\u5404\u4e2a\u7ebf\u7a0b\u8fd0\u884c\u60c5\u51b5\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u9996\u5148\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528top\u547d\u4ee4\u67e5\u770b\u7cfb\u7edfCPU\u7684\u5360\u7528\u60c5\u51b5\uff0c\u5982\u4e0b\u662f\u7cfb\u7edfCPU\u8f83\u9ad8\u7684\u4e00\u4e2a\u793a\u4f8b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>top -Hp 9<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8be5\u8fdb\u7a0b\u4e0b\u7684\u5404\u4e2a\u7ebf\u7a0b\u8fd0\u884c\u60c5\u51b5\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>top - 08:31:16 up 30 min,  0 users,  load average: 0.75, 0.59, 0.35\nThreads:  11 total,   1 running,  10 sleeping,   0 stopped,   0 zombie\n%Cpu(s):  3.5 us,  0.6 sy,  0.0 ni, 95.9 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st\nKiB Mem:   2046460 total,  1924856 used,   121604 free,    14396 buffers\nKiB Swap:  1048572 total,        0 used,  1048572 free.  1192532 cached Mem\n\n  PID USER      PR  NI    VIRT    RES    SHR S %CPU %MEM     TIME+ COMMAND\n   10 root      20   0 2557160 289824  15872 R 79.3 14.2   0:41.49 java\n   11 root      20   0 2557160 289824  15872 S 13.2 14.2   0:06.78 java<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u53ef\u4ee5\u770b\u5230\uff0c\u5728\u8fdb\u7a0b\u4e3a9\u7684Java\u7a0b\u5e8f\u4e2d\u5404\u4e2a\u7ebf\u7a0b\u7684CPU\u5360\u7528\u60c5\u51b5\uff0c\u63a5\u4e0b\u6765\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7jstack\u547d\u4ee4\u67e5\u770b\u7ebf\u7a0bid\u4e3a10\u7684\u7ebf\u7a0b\u4e3a\u4ec0\u4e48\u8017\u8d39CPU\u6700\u9ad8\u3002\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u5728jsatck\u547d\u4ee4\u5c55\u793a\u7684\u7ed3\u679c\u4e2d\uff0c\u7ebf\u7a0bid\u90fd\u8f6c\u6362\u6210\u4e86\u5341\u516d\u8fdb\u5236\u5f62\u5f0f\u3002\u53ef\u4ee5\u7528\u5982\u4e0b\u547d\u4ee4\u67e5\u770b\u8f6c\u6362\u7ed3\u679c\uff0c\u4e5f\u53ef\u4ee5\u627e\u4e00\u4e2a\u79d1\u5b66\u8ba1\u7b97\u5668\u8fdb\u884c\u8f6c\u6362\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>root@a39de7e7934b:\/# printf \"%x\\n\" 10\na<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u91cc\u6253\u5370\u7ed3\u679c\u8bf4\u660e\u8be5\u7ebf\u7a0b\u5728jstack\u4e2d\u7684\u5c55\u73b0\u5f62\u5f0f\u4e3a0xa\uff0c\u901a\u8fc7jstack\u547d\u4ee4\u6211\u4eec\u53ef\u4ee5\u770b\u5230\u5982\u4e0b\u4fe1\u606f\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\"main\" #1 prio=5 os_prio=0 tid=0x00007f8718009800 nid=0xb runnable [0x00007f871fe41000]\n   java.lang.Thread.State: RUNNABLE\n\tat com.aibaobei.chapter2.eg2.UserDemo.main(UserDemo.java:9)\n\n\"VM Thread\" os_prio=0 tid=0x00007f871806e000 nid=0xa runnable<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u91cc\u7684VM Thread\u4e00\u884c\u7684\u6700\u540e\u663e\u793anid=0xa\uff0c\u8fd9\u91ccnid\u7684\u610f\u601d\u5c31\u662f\u64cd\u4f5c\u7cfb\u7edf\u7ebf\u7a0bid\u7684\u610f\u601d\u3002\u800cVM Thread\u6307\u7684\u5c31\u662f\u5783\u573e\u56de\u6536\u7684\u7ebf\u7a0b\u3002\u8fd9\u91cc\u6211\u4eec\u57fa\u672c\u4e0a\u53ef\u4ee5\u786e\u5b9a\uff0c\u5f53\u524d\u7cfb\u7edf\u7f13\u6162\u7684\u539f\u56e0\u4e3b\u8981\u662f\u5783\u573e\u56de\u6536\u8fc7\u4e8e\u9891\u7e41\uff0c\u5bfc\u81f4GC\u505c\u987f\u65f6\u95f4\u8f83\u957f\u3002\u6211\u4eec\u901a\u8fc7\u5982\u4e0b\u547d\u4ee4\u53ef\u4ee5\u67e5\u770bGC\u7684\u60c5\u51b5\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>root@8d36124607a0:\/# jstat -gcutil 9 1000 10\n  S0     S1     E      O      M     CCS    YGC     YGCT    FGC    FGCT     GCT\n  0.00   0.00   0.00  75.07  59.09  59.60   3259    0.919  6517    7.715    8.635\n  0.00   0.00   0.00   0.08  59.09  59.60   3306    0.930  6611    7.822    8.752\n  0.00   0.00   0.00   0.08  59.09  59.60   3351    0.943  6701    7.924    8.867\n  0.00   0.00   0.00   0.08  59.09  59.60   3397    0.955  6793    8.029    8.984<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u53ef\u4ee5\u770b\u5230\uff0c\u8fd9\u91ccFGC\u6307\u7684\u662fFull GC\u6570\u91cf\uff0c\u8fd9\u91cc\u9ad8\u8fbe6793\uff0c\u800c\u4e14\u8fd8\u5728\u4e0d\u65ad\u589e\u957f\u3002\u4ece\u800c\u8fdb\u4e00\u6b65\u8bc1\u5b9e\u4e86\u662f\u7531\u4e8e\u5185\u5b58\u6ea2\u51fa\u5bfc\u81f4\u7684\u7cfb\u7edf\u7f13\u6162\u3002\u90a3\u4e48\u8fd9\u91cc\u786e\u8ba4\u4e86\u5185\u5b58\u6ea2\u51fa\uff0c\u4f46\u662f\u5982\u4f55\u67e5\u770b\u4f60\u662f\u54ea\u4e9b\u5bf9\u8c61\u5bfc\u81f4\u7684\u5185\u5b58\u6ea2\u51fa\u5462\uff0c\u8fd9\u4e2a\u53ef\u4ee5dump\u51fa\u5185\u5b58\u65e5\u5fd7\uff0c\u7136\u540e\u901a\u8fc7eclipse\u7684mat\u5de5\u5177\u8fdb\u884c\u67e5\u770b\uff0c\u5982\u4e0b\u662f\u5176\u5c55\u793a\u7684\u4e00\u4e2a\u5bf9\u8c61\u6811\u7ed3\u6784\uff1a<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img decoding=\"async\" src=\"https:\/\/images.weserv.nl\/?url=https:\/\/oscimg.oschina.net\/oscnet\/65fe863f6fe94eb05e48fd0835637be726d.jpg\" alt=\"\" \/><figcaption>eclipse \u7684 mat \u5de5\u5177\u67e5\u770b\u5bf9\u8c61\u7ed3\u6784<\/figcaption><\/figure><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ecf\u8fc7mat\u5de5\u5177\u5206\u6790\u4e4b\u540e\uff0c\u6211\u4eec\u57fa\u672c\u4e0a\u5c31\u80fd\u786e\u5b9a\u5185\u5b58\u4e2d\u4e3b\u8981\u662f\u54ea\u4e2a\u5bf9\u8c61\u6bd4\u8f83\u6d88\u8017\u5185\u5b58\uff0c\u7136\u540e\u627e\u5230\u8be5\u5bf9\u8c61\u7684\u521b\u5efa\u4f4d\u7f6e\uff0c\u8fdb\u884c\u5904\u7406\u5373\u53ef\u3002\u8fd9\u91cc\u7684\u4e3b\u8981\u662fPrintStream\u6700\u591a\uff0c\u4f46\u662f\u6211\u4eec\u4e5f\u53ef\u4ee5\u770b\u5230\uff0c\u5176\u5185\u5b58\u6d88\u8017\u91cf\u53ea\u670912.2%\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u5176\u8fd8\u4e0d\u8db3\u4ee5\u5bfc\u81f4\u5927\u91cf\u7684Full GC\uff0c\u6b64\u65f6\u6211\u4eec\u9700\u8981\u8003\u8651\u53e6\u5916\u4e00\u79cd\u60c5\u51b5\uff0c\u5c31\u662f\u4ee3\u7801\u6216\u8005\u7b2c\u4e09\u65b9\u4f9d\u8d56\u7684\u5305\u4e2d\u6709\u663e\u793a\u7684System.gc()\u8c03\u7528\u3002\u8fd9\u79cd\u60c5\u51b5\u6211\u4eec\u67e5\u770bdump\u5185\u5b58\u5f97\u5230\u7684\u6587\u4ef6\u5373\u53ef\u5224\u65ad\uff0c\u56e0\u4e3a\u5176\u4f1a\u6253\u5370GC\u539f\u56e0\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>[Full GC (System.gc()) [Tenured: 262546K-&gt;262546K(349568K), 0.0014879 secs] 262546K-&gt;262546K(506816K), [Metaspace: 3109K-&gt;3109K(1056768K)], 0.0015151 secs] [Times: user=0.00 sys=0.00, real=0.01 secs] \n[GC (Allocation Failure) [DefNew: 2795K-&gt;0K(157248K), 0.0001504 secs][Tenured: 262546K-&gt;402K(349568K), 0.0012949 secs] 265342K-&gt;402K(506816K), [Metaspace: 3109K-&gt;3109K(1056768K)], 0.0014699 secs] [Times: user=0.00<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u6bd4\u5982\u8fd9\u91cc\u7b2c\u4e00\u6b21GC\u662f\u7531\u4e8eSystem.gc()\u7684\u663e\u793a\u8c03\u7528\u5bfc\u81f4\u7684\uff0c\u800c\u7b2c\u4e8c\u6b21GC\u5219\u662fJVM\u4e3b\u52a8\u53d1\u8d77\u7684\u3002\u603b\u7ed3\u6765\u8bf4\uff0c\u5bf9\u4e8eFull GC\u6b21\u6570\u8fc7\u591a\uff0c\u4e3b\u8981\u6709\u4ee5\u4e0b\u4e24\u79cd\u539f\u56e0\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u4ee3\u7801\u4e2d\u4e00\u6b21\u83b7\u53d6\u4e86\u5927\u91cf\u7684\u5bf9\u8c61\uff0c\u5bfc\u81f4\u5185\u5b58\u6ea2\u51fa\uff0c\u6b64\u65f6\u53ef\u4ee5\u901a\u8fc7eclipse\u7684mat\u5de5\u5177\u67e5\u770b\u5185\u5b58\u4e2d\u6709\u54ea\u4e9b\u5bf9\u8c61\u6bd4\u8f83\u591a\uff1b<\/li><li>\u5185\u5b58\u5360\u7528\u4e0d\u9ad8\uff0c\u4f46\u662fFull GC\u6b21\u6570\u8fd8\u662f\u6bd4\u8f83\u591a\uff0c\u6b64\u65f6\u53ef\u80fd\u662f\u663e\u793a\u7684System.gc()\u8c03\u7528\u5bfc\u81f4GC\u6b21\u6570\u8fc7\u591a\uff0c\u8fd9\u53ef\u4ee5\u901a\u8fc7\u6dfb\u52a0-XX:+DisableExplicitGC\u6765\u7981\u7528JVM\u5bf9\u663e\u793aGC\u7684\u54cd\u5e94\u3002<\/li><\/ul>\n\n\n\n<h2>CPU\u8fc7\u9ad8<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u524d\u9762\u7b2c\u4e00\u70b9\u4e2d\uff0c\u6211\u4eec\u8bb2\u5230\uff0cCPU\u8fc7\u9ad8\u53ef\u80fd\u662f\u7cfb\u7edf\u9891\u7e41\u7684\u8fdb\u884cFull GC\uff0c\u5bfc\u81f4\u7cfb\u7edf\u7f13\u6162\u3002\u800c\u6211\u4eec\u5e73\u5e38\u4e5f\u80af\u80fd\u9047\u5230\u6bd4\u8f83\u8017\u65f6\u7684\u8ba1\u7b97\uff0c\u5bfc\u81f4CPU\u8fc7\u9ad8\u7684\u60c5\u51b5\uff0c\u6b64\u65f6\u67e5\u770b\u65b9\u5f0f\u5176\u5b9e\u4e0e\u4e0a\u9762\u7684\u975e\u5e38\u7c7b\u4f3c\u3002\u9996\u5148\u6211\u4eec\u901a\u8fc7top\u547d\u4ee4\u67e5\u770b\u5f53\u524dCPU\u6d88\u8017\u8fc7\u9ad8\u7684\u8fdb\u7a0b\u662f\u54ea\u4e2a\uff0c\u4ece\u800c\u5f97\u5230\u8fdb\u7a0bid\uff1b\u7136\u540e\u901a\u8fc7top -Hp \u6765\u67e5\u770b\u8be5\u8fdb\u7a0b\u4e2d\u6709\u54ea\u4e9b\u7ebf\u7a0bCPU\u8fc7\u9ad8\uff0c\u4e00\u822c\u8d85\u8fc780%\u5c31\u662f\u6bd4\u8f83\u9ad8\u7684\uff0c80%\u5de6\u53f3\u662f\u5408\u7406\u60c5\u51b5\u3002\u8fd9\u6837\u6211\u4eec\u5c31\u80fd\u5f97\u5230CPU\u6d88\u8017\u6bd4\u8f83\u9ad8\u7684\u7ebf\u7a0bid\u3002\u63a5\u7740\u901a\u8fc7\u8be5\u7ebf\u7a0bid\u7684\u5341\u516d\u8fdb\u5236\u8868\u793a\u5728jstack\u65e5\u5fd7\u4e2d\u67e5\u770b\u5f53\u524d\u7ebf\u7a0b\u5177\u4f53\u7684\u5806\u6808\u4fe1\u606f\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u8fd9\u91cc\u6211\u4eec\u5c31\u53ef\u4ee5\u533a\u5206\u5bfc\u81f4CPU\u8fc7\u9ad8\u7684\u539f\u56e0\u5177\u4f53\u662fFull GC\u6b21\u6570\u8fc7\u591a\u8fd8\u662f\u4ee3\u7801\u4e2d\u6709\u6bd4\u8f83\u8017\u65f6\u7684\u8ba1\u7b97\u4e86\u3002\u5982\u679c\u662fFull GC\u6b21\u6570\u8fc7\u591a\uff0c\u90a3\u4e48\u901a\u8fc7jstack\u5f97\u5230\u7684\u7ebf\u7a0b\u4fe1\u606f\u4f1a\u662f\u7c7b\u4f3c\u4e8eVM Thread\u4e4b\u7c7b\u7684\u7ebf\u7a0b\uff0c\u800c\u5982\u679c\u662f\u4ee3\u7801\u4e2d\u6709\u6bd4\u8f83\u8017\u65f6\u7684\u8ba1\u7b97\uff0c\u90a3\u4e48\u6211\u4eec\u5f97\u5230\u7684\u5c31\u662f\u4e00\u4e2a\u7ebf\u7a0b\u7684\u5177\u4f53\u5806\u6808\u4fe1\u606f\u3002\u5982\u4e0b\u662f\u4e00\u4e2a\u4ee3\u7801\u4e2d\u6709\u6bd4\u8f83\u8017\u65f6\u7684\u8ba1\u7b97\uff0c\u5bfc\u81f4CPU\u8fc7\u9ad8\u7684\u7ebf\u7a0b\u4fe1\u606f\uff1a<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img decoding=\"async\" src=\"https:\/\/images.weserv.nl\/?url=https:\/\/oscimg.oschina.net\/oscnet\/e1146eddc2dbf10ff28534abda323761369.jpg\" alt=\"\" \/><figcaption>jstack \u627e\u51fa CPU \u8fc7\u9ad8\u7684\u7ebf\u7a0b<\/figcaption><\/figure><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u91cc\u53ef\u4ee5\u770b\u5230\uff0c\u5728\u8bf7\u6c42UserController\u7684\u65f6\u5019\uff0c\u7531\u4e8e\u8be5Controller\u8fdb\u884c\u4e86\u4e00\u4e2a\u6bd4\u8f83\u8017\u65f6\u7684\u8c03\u7528\uff0c\u5bfc\u81f4\u8be5\u7ebf\u7a0b\u7684CPU\u4e00\u76f4\u5904\u4e8e100%\u3002\u6211\u4eec\u53ef\u4ee5\u6839\u636e\u5806\u6808\u4fe1\u606f\uff0c\u76f4\u63a5\u5b9a\u4f4d\u5230UserController\u768434\u884c\uff0c\u67e5\u770b\u4ee3\u7801\u4e2d\u5177\u4f53\u662f\u4ec0\u4e48\u539f\u56e0\u5bfc\u81f4\u8ba1\u7b97\u91cf\u5982\u6b64\u4e4b\u9ad8\u3002<\/p>\n\n\n\n<h2>\u4e0d\u5b9a\u671f\u51fa\u73b0\u7684\u63a5\u53e3\u8017\u65f6\u73b0\u8c61<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u5bf9\u4e8e\u8fd9\u79cd\u60c5\u51b5\uff0c\u6bd4\u8f83\u5178\u578b\u7684\u4f8b\u5b50\u5c31\u662f\uff0c\u6211\u4eec\u67d0\u4e2a\u63a5\u53e3\u8bbf\u95ee\u7ecf\u5e38\u9700\u89812~3s\u624d\u80fd\u8fd4\u56de\u3002\u8fd9\u662f\u6bd4\u8f83\u9ebb\u70e6\u7684\u4e00\u79cd\u60c5\u51b5\uff0c\u56e0\u4e3a\u4e00\u822c\u6765\u8bf4\uff0c\u5176\u6d88\u8017\u7684CPU\u4e0d\u591a\uff0c\u800c\u4e14\u5360\u7528\u7684\u5185\u5b58\u4e5f\u4e0d\u9ad8\uff0c\u4e5f\u5c31\u662f\u8bf4\uff0c\u6211\u4eec\u901a\u8fc7\u4e0a\u8ff0\u4e24\u79cd\u65b9\u5f0f\u8fdb\u884c\u6392\u67e5\u662f\u65e0\u6cd5\u89e3\u51b3\u8fd9\u79cd\u95ee\u9898\u7684\u3002\u800c\u4e14\u7531\u4e8e\u8fd9\u6837\u7684\u63a5\u53e3\u8017\u65f6\u6bd4\u8f83\u5927\u7684\u95ee\u9898\u662f\u4e0d\u5b9a\u65f6\u51fa\u73b0\u7684\uff0c\u8fd9\u5c31\u5bfc\u81f4\u4e86\u6211\u4eec\u5728\u901a\u8fc7jstack\u547d\u4ee4\u5373\u4f7f\u5f97\u5230\u4e86\u7ebf\u7a0b\u8bbf\u95ee\u7684\u5806\u6808\u4fe1\u606f\uff0c\u6211\u4eec\u4e5f\u6ca1\u6cd5\u5224\u65ad\u5177\u4f53\u54ea\u4e2a\u7ebf\u7a0b\u662f\u6b63\u5728\u6267\u884c\u6bd4\u8f83\u8017\u65f6\u64cd\u4f5c\u7684\u7ebf\u7a0b\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5bf9\u4e8e\u4e0d\u5b9a\u65f6\u51fa\u73b0\u7684\u63a5\u53e3\u8017\u65f6\u6bd4\u8f83\u4e25\u91cd\u7684\u95ee\u9898\uff0c\u6211\u4eec\u7684\u5b9a\u4f4d\u601d\u8def\u57fa\u672c\u5982\u4e0b\uff1a\u9996\u5148\u627e\u5230\u8be5\u63a5\u53e3\uff0c\u901a\u8fc7\u538b\u6d4b\u5de5\u5177\u4e0d\u65ad\u52a0\u5927\u8bbf\u95ee\u529b\u5ea6\uff0c\u5982\u679c\u8bf4\u8be5\u63a5\u53e3\u4e2d\u6709\u67d0\u4e2a\u4f4d\u7f6e\u662f\u6bd4\u8f83\u8017\u65f6\u7684\uff0c\u7531\u4e8e\u6211\u4eec\u7684\u8bbf\u95ee\u7684\u9891\u7387\u975e\u5e38\u9ad8\uff0c\u90a3\u4e48\u5927\u591a\u6570\u7684\u7ebf\u7a0b\u6700\u7ec8\u90fd\u5c06\u963b\u585e\u4e8e\u8be5\u963b\u585e\u70b9\uff0c\u8fd9\u6837\u901a\u8fc7\u591a\u4e2a\u7ebf\u7a0b\u5177\u6709\u76f8\u540c\u7684\u5806\u6808\u65e5\u5fd7\uff0c\u6211\u4eec\u57fa\u672c\u4e0a\u5c31\u53ef\u4ee5\u5b9a\u4f4d\u5230\u8be5\u63a5\u53e3\u4e2d\u6bd4\u8f83\u8017\u65f6\u7684\u4ee3\u7801\u7684\u4f4d\u7f6e\u3002\u5982\u4e0b\u662f\u4e00\u4e2a\u4ee3\u7801\u4e2d\u6709\u6bd4\u8f83\u8017\u65f6\u7684\u963b\u585e\u64cd\u4f5c\u901a\u8fc7\u538b\u6d4b\u5de5\u5177\u5f97\u5230\u7684\u7ebf\u7a0b\u5806\u6808\u65e5\u5fd7\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\"http-nio-8080-exec-2\" #29 daemon prio=5 os_prio=31 tid=0x00007fd08cb26000 nid=0x9603 waiting on condition [0x00007000031d5000]\n   java.lang.Thread.State: TIMED_WAITING (sleeping)\n\tat java.lang.Thread.sleep(Native Method)\n\tat java.lang.Thread.sleep(Thread.java:340)\n\tat java.util.concurrent.TimeUnit.sleep(TimeUnit.java:386)\n\tat com.aibaobei.user.controller.UserController.detail(UserController.java:18)\n\n\"http-nio-8080-exec-3\" #30 daemon prio=5 os_prio=31 tid=0x00007fd08cb27000 nid=0x6203 waiting on condition [0x00007000032d8000]\n   java.lang.Thread.State: TIMED_WAITING (sleeping)\n\tat java.lang.Thread.sleep(Native Method)\n\tat java.lang.Thread.sleep(Thread.java:340)\n\tat java.util.concurrent.TimeUnit.sleep(TimeUnit.java:386)\n\tat com.aibaobei.user.controller.UserController.detail(UserController.java:18)\n\n\"http-nio-8080-exec-4\" #31 daemon prio=5 os_prio=31 tid=0x00007fd08d0fa000 nid=0x6403 waiting on condition [0x00007000033db000]\n   java.lang.Thread.State: TIMED_WAITING (sleeping)\n\tat java.lang.Thread.sleep(Native Method)\n\tat java.lang.Thread.sleep(Thread.java:340)\n\tat java.util.concurrent.TimeUnit.sleep(TimeUnit.java:386)\n\tat com.aibaobei.user.controller.UserController.detail(UserController.java:18)<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ece\u4e0a\u9762\u7684\u65e5\u5fd7\u53ef\u4ee5\u770b\u4f60\u51fa\uff0c\u8fd9\u91cc\u6709\u591a\u4e2a\u7ebf\u7a0b\u90fd\u963b\u585e\u5728\u4e86UserController\u7684\u7b2c18\u884c\uff0c\u8bf4\u660e\u8fd9\u662f\u4e00\u4e2a\u963b\u585e\u70b9\uff0c\u4e5f\u5c31\u662f\u5bfc\u81f4\u8be5\u63a5\u53e3\u6bd4\u8f83\u7f13\u6162\u7684\u539f\u56e0\u3002<\/p>\n\n\n\n<h2>\u67d0\u4e2a\u7ebf\u7a0b\u8fdb\u5165WAITING\u72b6\u6001<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u5bf9\u4e8e\u8fd9\u79cd\u60c5\u51b5\uff0c\u8fd9\u662f\u6bd4\u8f83\u7f55\u89c1\u7684\u4e00\u79cd\u60c5\u51b5\uff0c\u4f46\u662f\u4e5f\u662f\u6709\u53ef\u80fd\u51fa\u73b0\u7684\uff0c\u800c\u4e14\u7531\u4e8e\u5176\u5177\u6709\u4e00\u5b9a\u7684\u201c\u4e0d\u53ef\u590d\u73b0\u6027\u201d\uff0c\u56e0\u800c\u6211\u4eec\u5728\u6392\u67e5\u7684\u65f6\u5019\u662f\u975e\u5e38\u96be\u4ee5\u53d1\u73b0\u7684\u3002\u7b14\u8005\u66fe\u7ecf\u5c31\u9047\u5230\u8fc7\u7c7b\u4f3c\u7684\u8fd9\u79cd\u60c5\u51b5\uff0c\u5177\u4f53\u7684\u573a\u666f\u662f\uff0c\u5728\u4f7f\u7528CountDownLatch\u65f6\uff0c\u7531\u4e8e\u9700\u8981\u6bcf\u4e00\u4e2a\u5e76\u884c\u7684\u4efb\u52a1\u90fd\u6267\u884c\u5b8c\u6210\u4e4b\u540e\u624d\u4f1a\u5524\u9192\u4e3b\u7ebf\u7a0b\u5f80\u4e0b\u6267\u884c\u3002\u800c\u5f53\u65f6\u6211\u4eec\u662f\u901a\u8fc7CountDownLatch\u63a7\u5236\u591a\u4e2a\u7ebf\u7a0b\u8fde\u63a5\u5e76\u5bfc\u51fa\u7528\u6237\u7684gmail\u90ae\u7bb1\u6570\u636e\uff0c\u8fd9\u5176\u4e2d\u6709\u4e00\u4e2a\u7ebf\u7a0b\u8fde\u63a5\u4e0a\u4e86\u7528\u6237\u90ae\u7bb1\uff0c\u4f46\u662f\u8fde\u63a5\u88ab\u670d\u52a1\u5668\u6302\u8d77\u4e86\uff0c\u5bfc\u81f4\u8be5\u7ebf\u7a0b\u4e00\u76f4\u5728\u7b49\u5f85\u670d\u52a1\u5668\u7684\u54cd\u5e94\u3002\u6700\u7ec8\u5bfc\u81f4\u6211\u4eec\u7684\u4e3b\u7ebf\u7a0b\u548c\u5176\u4f59\u51e0\u4e2a\u7ebf\u7a0b\u90fd\u5904\u4e8eWAITING\u72b6\u6001\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5bf9\u4e8e\u8fd9\u6837\u7684\u95ee\u9898\uff0c\u67e5\u770b\u8fc7jstack\u65e5\u5fd7\u7684\u8bfb\u8005\u5e94\u8be5\u90fd\u77e5\u9053\uff0c\u6b63\u5e38\u60c5\u51b5\u4e0b\uff0c\u7ebf\u4e0a\u5927\u591a\u6570\u7ebf\u7a0b\u90fd\u662f\u5904\u4e8eTIMED_WAITING\u72b6\u6001\uff0c\u800c\u6211\u4eec\u8fd9\u91cc\u51fa\u95ee\u9898\u7684\u7ebf\u7a0b\u6240\u5904\u7684\u72b6\u6001\u4e0e\u5176\u662f\u4e00\u6a21\u4e00\u6837\u7684\uff0c\u8fd9\u5c31\u975e\u5e38\u5bb9\u6613\u6df7\u6dc6\u6211\u4eec\u7684\u5224\u65ad\u3002\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u7684\u601d\u8def\u4e3b\u8981\u5982\u4e0b\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u901a\u8fc7grep\u5728jstack\u65e5\u5fd7\u4e2d\u627e\u51fa\u6240\u6709\u7684\u5904\u4e8eTIMED_WAITING\u72b6\u6001\u7684\u7ebf\u7a0b\uff0c\u5c06\u5176\u5bfc\u51fa\u5230\u67d0\u4e2a\u6587\u4ef6\u4e2d\uff0c\u5982a1.log\uff0c\u5982\u4e0b\u662f\u4e00\u4e2a\u5bfc\u51fa\u7684\u65e5\u5fd7\u6587\u4ef6\u793a\u4f8b\uff1a<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>\"Attach Listener\" #13 daemon prio=9 os_prio=31 tid=0x00007fe690064000 nid=0xd07 waiting on condition [0x0000000000000000]\n\"DestroyJavaVM\" #12 prio=5 os_prio=31 tid=0x00007fe690066000 nid=0x2603 waiting on condition [0x0000000000000000]\n\"Thread-0\" #11 prio=5 os_prio=31 tid=0x00007fe690065000 nid=0x5a03 waiting on condition [0x0000700003ad4000]\n\"C1 CompilerThread3\" #9 daemon prio=9 os_prio=31 tid=0x00007fe68c00a000 nid=0xa903 waiting on condition [0x0000000000000000]<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\"><li>\u7b49\u5f85\u4e00\u6bb5\u65f6\u95f4\u4e4b\u540e\uff0c\u6bd4\u598210s\uff0c\u518d\u6b21\u5bf9jstack\u65e5\u5fd7\u8fdb\u884cgrep\uff0c\u5c06\u5176\u5bfc\u51fa\u5230\u53e6\u4e00\u4e2a\u6587\u4ef6\uff0c\u5982a2.log\uff0c\u7ed3\u679c\u5982\u4e0b\u6240\u793a\uff1a<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>\"DestroyJavaVM\" #12 prio=5 os_prio=31 tid=0x00007fe690066000 nid=0x2603 waiting on condition [0x0000000000000000]\n\"Thread-0\" #11 prio=5 os_prio=31 tid=0x00007fe690065000 nid=0x5a03 waiting on condition [0x0000700003ad4000]\n\"VM Periodic Task Thread\" os_prio=31 tid=0x00007fe68d114000 nid=0xa803 waiting on condition<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\"><li>\u91cd\u590d\u6b65\u9aa42\uff0c\u5f85\u5bfc\u51fa3~4\u4e2a\u6587\u4ef6\u4e4b\u540e\uff0c\u6211\u4eec\u5bf9\u5bfc\u51fa\u7684\u6587\u4ef6\u8fdb\u884c\u5bf9\u6bd4\uff0c\u627e\u51fa\u5176\u4e2d\u5728\u8fd9\u51e0\u4e2a\u6587\u4ef6\u4e2d\u4e00\u76f4\u90fd\u5b58\u5728\u7684\u7528\u6237\u7ebf\u7a0b\uff0c\u8fd9\u4e2a\u7ebf\u7a0b\u57fa\u672c\u4e0a\u5c31\u53ef\u4ee5\u786e\u8ba4\u662f\u5305\u542b\u4e86\u5904\u4e8e\u7b49\u5f85\u72b6\u6001\u6709\u95ee\u9898\u7684\u7ebf\u7a0b\u3002\u56e0\u4e3a\u6b63\u5e38\u7684\u8bf7\u6c42\u7ebf\u7a0b\u662f\u4e0d\u4f1a\u572820~30s\u4e4b\u540e\u8fd8\u662f\u5904\u4e8e\u7b49\u5f85\u72b6\u6001\u7684\u3002<\/li><li>\u7ecf\u8fc7\u6392\u67e5\u5f97\u5230\u8fd9\u4e9b\u7ebf\u7a0b\u4e4b\u540e\uff0c\u6211\u4eec\u53ef\u4ee5\u7ee7\u7eed\u5bf9\u5176\u5806\u6808\u4fe1\u606f\u8fdb\u884c\u6392\u67e5\uff0c\u5982\u679c\u8be5\u7ebf\u7a0b\u672c\u8eab\u5c31\u5e94\u8be5\u5904\u4e8e\u7b49\u5f85\u72b6\u6001\uff0c\u6bd4\u5982\u7528\u6237\u521b\u5efa\u7684\u7ebf\u7a0b\u6c60\u4e2d\u5904\u4e8e\u7a7a\u95f2\u72b6\u6001\u7684\u7ebf\u7a0b\uff0c\u90a3\u4e48\u8fd9\u79cd\u7ebf\u7a0b\u7684\u5806\u6808\u4fe1\u606f\u4e2d\u662f\u4e0d\u4f1a\u5305\u542b\u7528\u6237\u81ea\u5b9a\u4e49\u7684\u7c7b\u7684\u3002\u8fd9\u4e9b\u90fd\u53ef\u4ee5\u6392\u9664\u6389\uff0c\u800c\u5269\u4e0b\u7684\u7ebf\u7a0b\u57fa\u672c\u4e0a\u5c31\u53ef\u4ee5\u786e\u8ba4\u662f\u6211\u4eec\u8981\u627e\u7684\u6709\u95ee\u9898\u7684\u7ebf\u7a0b\u3002\u901a\u8fc7\u5176\u5806\u6808\u4fe1\u606f\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u5f97\u51fa\u5177\u4f53\u662f\u5728\u54ea\u4e2a\u4f4d\u7f6e\u7684\u4ee3\u7801\u5bfc\u81f4\u8be5\u7ebf\u7a0b\u5904\u4e8e\u7b49\u5f85\u72b6\u6001\u4e86\u3002<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u91cc\u9700\u8981\u8bf4\u660e\u7684\u662f\uff0c\u6211\u4eec\u5728\u5224\u65ad\u662f\u5426\u4e3a\u7528\u6237\u7ebf\u7a0b\u65f6\uff0c\u53ef\u4ee5\u901a\u8fc7\u7ebf\u7a0b\u6700\u524d\u9762\u7684\u7ebf\u7a0b\u540d\u6765\u5224\u65ad\uff0c\u56e0\u4e3a\u4e00\u822c\u7684\u6846\u67b6\u7684\u7ebf\u7a0b\u547d\u540d\u90fd\u662f\u975e\u5e38\u89c4\u8303\u7684\uff0c\u6211\u4eec\u901a\u8fc7\u7ebf\u7a0b\u540d\u5c31\u53ef\u4ee5\u76f4\u63a5\u5224\u65ad\u5f97\u51fa\u8be5\u7ebf\u7a0b\u662f\u67d0\u4e9b\u6846\u67b6\u4e2d\u7684\u7ebf\u7a0b\uff0c\u8fd9\u79cd\u7ebf\u7a0b\u57fa\u672c\u4e0a\u53ef\u4ee5\u6392\u9664\u6389\u3002\u800c\u5269\u4f59\u7684\uff0c\u6bd4\u5982\u4e0a\u9762\u7684Thread-0\uff0c\u4ee5\u53ca\u6211\u4eec\u53ef\u4ee5\u8fa8\u522b\u7684\u81ea\u5b9a\u4e49\u7ebf\u7a0b\u540d\uff0c\u8fd9\u4e9b\u90fd\u662f\u6211\u4eec\u9700\u8981\u6392\u67e5\u7684\u5bf9\u8c61\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ecf\u8fc7\u4e0a\u9762\u7684\u65b9\u5f0f\u8fdb\u884c\u6392\u67e5\u4e4b\u540e\uff0c\u6211\u4eec\u57fa\u672c\u4e0a\u5c31\u53ef\u4ee5\u5f97\u51fa\u8fd9\u91cc\u7684Thread-0\u5c31\u662f\u6211\u4eec\u8981\u627e\u7684\u7ebf\u7a0b\uff0c\u901a\u8fc7\u67e5\u770b\u5176\u5806\u6808\u4fe1\u606f\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u5f97\u5230\u5177\u4f53\u662f\u5728\u54ea\u4e2a\u4f4d\u7f6e\u5bfc\u81f4\u5176\u5904\u4e8e\u7b49\u5f85\u72b6\u6001\u4e86\u3002\u5982\u4e0b\u793a\u4f8b\u4e2d\u5219\u662f\u5728SyncTask\u7684\u7b2c8\u884c\u5bfc\u81f4\u8be5\u7ebf\u7a0b\u8fdb\u5165\u7b49\u5f85\u4e86\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\"Thread-0\" #11 prio=5 os_prio=31 tid=0x00007f9de08c7000 nid=0x5603 waiting on condition [0x0000700001f89000]\n   java.lang.Thread.State: WAITING (parking)\n\tat sun.misc.Unsafe.park(Native Method)\n\tat java.util.concurrent.locks.LockSupport.park(LockSupport.java:304)\n\tat com.aibaobei.chapter2.eg4.SyncTask.lambda$main$0(SyncTask.java:8)\n\tat com.aibaobei.chapter2.eg4.SyncTask$$Lambda$1\/1791741888.run(Unknown Source)\n\tat java.lang.Thread.run(Thread.java:748)<\/code><\/pre>\n\n\n\n<h2>\u6b7b\u9501<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u5bf9\u4e8e\u6b7b\u9501\uff0c\u8fd9\u79cd\u60c5\u51b5\u57fa\u672c\u4e0a\u5f88\u5bb9\u6613\u53d1\u73b0\uff0c\u56e0\u4e3ajstack\u53ef\u4ee5\u5e2e\u52a9\u6211\u4eec\u68c0\u67e5\u6b7b\u9501\uff0c\u5e76\u4e14\u5728\u65e5\u5fd7\u4e2d\u6253\u5370\u5177\u4f53\u7684\u6b7b\u9501\u7ebf\u7a0b\u4fe1\u606f\u3002\u5982\u4e0b\u662f\u4e00\u4e2a\u4ea7\u751f\u6b7b\u9501\u7684\u4e00\u4e2ajstack\u65e5\u5fd7\u793a\u4f8b\uff1a<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img decoding=\"async\" src=\"https:\/\/images.weserv.nl\/?url=https:\/\/oscimg.oschina.net\/oscnet\/d488242cef4cddc3e27c6cb737d0a7cc3ec.jpg\" alt=\"\" \/><figcaption>jstack\u65e5\u5fd7\u793a\u4f8b<\/figcaption><\/figure><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">\u53ef\u4ee5\u770b\u5230\uff0c\u5728jstack\u65e5\u5fd7\u7684\u5e95\u90e8\uff0c\u5176\u76f4\u63a5\u5e2e\u6211\u4eec\u5206\u6790\u4e86\u65e5\u5fd7\u4e2d\u5b58\u5728\u54ea\u4e9b\u6b7b\u9501\uff0c\u4ee5\u53ca\u6bcf\u4e2a\u6b7b\u9501\u7684\u7ebf\u7a0b\u5806\u6808\u4fe1\u606f\u3002\u8fd9\u91cc\u6211\u4eec\u6709\u4e24\u4e2a\u7528\u6237\u7ebf\u7a0b\u5206\u522b\u5728\u7b49\u5f85\u5bf9\u65b9\u91ca\u653e\u9501\uff0c\u800c\u88ab\u963b\u585e\u7684\u4f4d\u7f6e\u90fd\u662f\u5728ConnectTask\u7684\u7b2c5\u884c\uff0c\u6b64\u65f6\u6211\u4eec\u5c31\u53ef\u4ee5\u76f4\u63a5\u5b9a\u4f4d\u5230\u8be5\u4f4d\u7f6e\uff0c\u5e76\u4e14\u8fdb\u884c\u4ee3\u7801\u5206\u6790\uff0c\u4ece\u800c\u627e\u5230\u4ea7\u751f\u6b7b\u9501\u7684\u539f\u56e0\u3002<\/p>\n\n\n\n<h2>\u5c0f\u7ed3<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u672c\u6587\u4e3b\u8981\u8bb2\u89e3\u4e86\u7ebf\u4e0a\u53ef\u80fd\u51fa\u73b0\u7684\u4e94\u79cd\u5bfc\u81f4\u7cfb\u7edf\u7f13\u6162\u7684\u60c5\u51b5\uff0c\u8be6\u7ec6\u5206\u6790\u4e86\u6bcf\u79cd\u60c5\u51b5\u4ea7\u751f\u65f6\u7684\u73b0\u8c61\uff0c\u5df2\u7ecf\u6839\u636e\u73b0\u8c61\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u54ea\u4e9b\u65b9\u5f0f\u5b9a\u4f4d\u5f97\u5230\u662f\u8fd9\u79cd\u539f\u56e0\u5bfc\u81f4\u7684\u7cfb\u7edf\u7f13\u6162\u3002\u7b80\u8981\u7684\u8bf4\uff0c\u6211\u4eec\u8fdb\u884c\u7ebf\u4e0a\u65e5\u5fd7\u5206\u6790\u65f6\uff0c\u4e3b\u8981\u53ef\u4ee5\u5206\u4e3a\u5982\u4e0b\u6b65\u9aa4\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u901a\u8fc7<code>top<\/code>\u547d\u4ee4\u67e5\u770bCPU\u60c5\u51b5\uff0c\u5982\u679cCPU\u6bd4\u8f83\u9ad8\uff0c\u5219\u901a\u8fc7<code>top -Hp &lt;pid&gt;<\/code>\u547d\u4ee4\u67e5\u770b\u5f53\u524d\u8fdb\u7a0b\u7684\u5404\u4e2a\u7ebf\u7a0b\u8fd0\u884c\u60c5\u51b5\uff0c\u627e\u51faCPU\u8fc7\u9ad8\u7684\u7ebf\u7a0b\u4e4b\u540e\uff0c\u5c06\u5176\u7ebf\u7a0bid\u8f6c\u6362\u4e3a\u5341\u516d\u8fdb\u5236\u7684\u8868\u73b0\u5f62\u5f0f\uff0c\u7136\u540e\u5728jstack\u65e5\u5fd7\u4e2d\u67e5\u770b\u8be5\u7ebf\u7a0b\u4e3b\u8981\u5728\u8fdb\u884c\u7684\u5de5\u4f5c\u3002\u8fd9\u91cc\u53c8\u5206\u4e3a\u4e24\u79cd\u60c5\u51b5<ul><li>\u5982\u679c\u662f\u6b63\u5e38\u7684\u7528\u6237\u7ebf\u7a0b\uff0c\u5219\u901a\u8fc7\u8be5\u7ebf\u7a0b\u7684\u5806\u6808\u4fe1\u606f\u67e5\u770b\u5176\u5177\u4f53\u662f\u5728\u54ea\u5904\u7528\u6237\u4ee3\u7801\u5904\u8fd0\u884c\u6bd4\u8f83\u6d88\u8017CPU\uff1b<\/li><li>\u5982\u679c\u8be5\u7ebf\u7a0b\u662f<code>VM Thread<\/code>\uff0c\u5219\u901a\u8fc7<code>jstat -gcutil &lt;pid&gt; &lt;period&gt; &lt;times&gt;<\/code>\u547d\u4ee4\u76d1\u63a7\u5f53\u524d\u7cfb\u7edf\u7684GC\u72b6\u51b5\uff0c\u7136\u540e\u901a\u8fc7<code>jmap dump:format=b,file=&lt;filepath&gt; &lt;pid&gt;<\/code>\u5bfc\u51fa\u7cfb\u7edf\u5f53\u524d\u7684\u5185\u5b58\u6570\u636e\u3002\u5bfc\u51fa\u4e4b\u540e\u5c06\u5185\u5b58\u60c5\u51b5\u653e\u5230eclipse\u7684mat\u5de5\u5177\u4e2d\u8fdb\u884c\u5206\u6790\u5373\u53ef\u5f97\u51fa\u5185\u5b58\u4e2d\u4e3b\u8981\u662f\u4ec0\u4e48\u5bf9\u8c61\u6bd4\u8f83\u6d88\u8017\u5185\u5b58\uff0c\u8fdb\u800c\u53ef\u4ee5\u5904\u7406\u76f8\u5173\u4ee3\u7801\uff1b<\/li><\/ul><\/li><li>\u5982\u679c\u901a\u8fc7<code>top<\/code>\u547d\u4ee4\u770b\u5230CPU\u5e76\u4e0d\u9ad8\uff0c\u5e76\u4e14\u7cfb\u7edf\u5185\u5b58\u5360\u7528\u7387\u4e5f\u6bd4\u8f83\u4f4e\u3002\u6b64\u65f6\u5c31\u53ef\u4ee5\u8003\u8651\u662f\u5426\u662f\u7531\u4e8e\u53e6\u5916\u4e09\u79cd\u60c5\u51b5\u5bfc\u81f4\u7684\u95ee\u9898\u3002\u5177\u4f53\u7684\u53ef\u4ee5\u6839\u636e\u5177\u4f53\u60c5\u51b5\u5206\u6790\uff1a<ul><li>\u5982\u679c\u662f\u63a5\u53e3\u8c03\u7528\u6bd4\u8f83\u8017\u65f6\uff0c\u5e76\u4e14\u662f\u4e0d\u5b9a\u65f6\u51fa\u73b0\uff0c\u5219\u53ef\u4ee5\u901a\u8fc7\u538b\u6d4b\u7684\u65b9\u5f0f\u52a0\u5927\u963b\u585e\u70b9\u51fa\u73b0\u7684\u9891\u7387\uff0c\u4ece\u800c\u901a\u8fc7<code>jstack<\/code>\u67e5\u770b\u5806\u6808\u4fe1\u606f\uff0c\u627e\u5230\u963b\u585e\u70b9\uff1b<\/li><li>\u5982\u679c\u662f\u67d0\u4e2a\u529f\u80fd\u7a81\u7136\u51fa\u73b0\u505c\u6ede\u7684\u72b6\u51b5\uff0c\u8fd9\u79cd\u60c5\u51b5\u4e5f\u65e0\u6cd5\u590d\u73b0\uff0c\u6b64\u65f6\u53ef\u4ee5\u901a\u8fc7\u591a\u6b21\u5bfc\u51fa<code>jstack<\/code>\u65e5\u5fd7\u7684\u65b9\u5f0f\u5bf9\u6bd4\u54ea\u4e9b\u7528\u6237\u7ebf\u7a0b\u662f\u4e00\u76f4\u90fd\u5904\u4e8e\u7b49\u5f85\u72b6\u6001\uff0c\u8fd9\u4e9b\u7ebf\u7a0b\u5c31\u662f\u53ef\u80fd\u5b58\u5728\u95ee\u9898\u7684\u7ebf\u7a0b\uff1b<\/li><li>\u5982\u679c\u901a\u8fc7<code>jstack<\/code>\u53ef\u4ee5\u67e5\u770b\u5230\u6b7b\u9501\u72b6\u6001\uff0c\u5219\u53ef\u4ee5\u68c0\u67e5\u4ea7\u751f\u6b7b\u9501\u7684\u4e24\u4e2a\u7ebf\u7a0b\u7684\u5177\u4f53\u963b\u585e\u70b9\uff0c\u4ece\u800c\u5904\u7406\u76f8\u5e94\u7684\u95ee\u9898\u3002<\/li><\/ul><\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u672c\u6587\u4e3b\u8981\u662f\u63d0\u51fa\u4e86\u4e94\u79cd\u5e38\u89c1\u7684\u5bfc\u81f4\u7ebf\u4e0a\u529f\u80fd\u7f13\u6162\u7684\u95ee\u9898\uff0c\u4ee5\u53ca\u6392\u67e5\u601d\u8def\u3002\u5f53\u7136\uff0c\u7ebf\u4e0a\u7684\u95ee\u9898\u51fa\u73b0\u7684\u5f62\u5f0f\u662f\u591a\u79cd\u591a\u6837\u7684\uff0c\u4e5f\u4e0d\u4e00\u5b9a\u5c40\u9650\u4e8e\u8fd9\u51e0\u79cd\u60c5\u51b5\uff0c\u5982\u679c\u6211\u4eec\u80fd\u591f\u4ed4\u7ec6\u5206\u6790\u8fd9\u4e9b\u95ee\u9898\u51fa\u73b0\u7684\u573a\u666f\uff0c\u5c31\u53ef\u4ee5\u6839\u636e\u5177\u4f53\u60c5\u51b5\u5177\u4f53\u5206\u6790\uff0c\u4ece\u800c\u89e3\u51b3\u76f8\u5e94\u7684\u95ee\u9898\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u53c2\u8003\u94fe\u63a5\uff1a<a href=\"https:\/\/mp.weixin.qq.com\/s\/EoyN1L5_0G6MJFtY5UvpBg\" target=\"_blank\" rel=\"noreferrer noopener\" aria-label=\"https:\/\/mp.weixin.qq.com\/s\/EoyN1L5_0G6MJFtY5UvpBg\uff08\u5728\u65b0\u7a97\u53e3\u6253\u5f00\uff09\">https:\/\/mp.weixin.qq.com\/s\/EoyN1L5_0G6MJFtY5UvpBg<\/a><\/p>\n<!-- <audio autoplay=\"autoplay\" height=\"100\" width=\"100\" hidden=\"true\"><source src=\"https:\/\/c.coka.la\/orAvPR.mp3\" type=\"audio\/mp3\"\/><\/audio><img decoding=\"async\" src=\"https:\/\/images.weserv.nl\/?url=https:\/\/ws3.sinaimg.cn\/large\/8fa5dcfcgy1g4em3rzar5j20ib089ae0.jpg\" alt=\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/> --><p><!-- <img decoding=\"async\" src=\"https:\/\/raw.githubusercontent.com\/xmt1139057136\/xttblog\/master\/8fa5dcfcgy1g4em3rzar5j20ib089ae0.jpg\" alt=\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/>--><img decoding=\"async\" src=\"https:\/\/saas.51autoparts.cn\/api\/admin\/sys-file\/oss\/file?fileName=84db51f8561e448f9a4fda2eff0811f9.jpg\" alt=\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/><\/p><p>\u6700\u540e\uff0c\u6b22\u8fce\u5173\u6ce8\u6211\u7684\u4e2a\u4eba\u5fae\u4fe1\u516c\u4f17\u53f7\uff1a\u4e1a\u4f59\u8349\uff08yyucao\uff09\uff01<b>\u53ef\u52a0\u4f5c\u8005\u5fae\u4fe1\u53f7\uff1a<font color=\"red\">xttblog2<\/font>\u3002\u5907\u6ce8\uff1a\u201c1\u201d\uff0c\u6dfb\u52a0\u535a\u4e3b\u5fae\u4fe1\u62c9\u4f60\u8fdb\u5fae\u4fe1\u7fa4\u3002\u5907\u6ce8\u9519\u8bef\u4e0d\u4f1a\u540c\u610f\u597d\u53cb\u7533\u8bf7\u3002<\/b>\u518d\u6b21\u611f\u8c22\u60a8\u7684\u5173\u6ce8\uff01\u540e\u7eed\u6709\u7cbe\u5f69\u5185\u5bb9\u4f1a\u7b2c\u4e00\u65f6\u95f4\u53d1\u7ed9\u60a8\uff01\u539f\u521b\u6587\u7ae0\u6295\u7a3f\u8bf7\u53d1\u9001\u81f3532009913@qq.com\u90ae\u7bb1\u3002\u5546\u52a1\u5408\u4f5c\u4e5f\u53ef\u6dfb\u52a0\u4f5c\u8005\u5fae\u4fe1\u8fdb\u884c\u8054\u7cfb\uff01<\/p><p>\u672c\u6587\u539f\u6587\u51fa\u5904\uff1a<a href=\"https:\/\/www.xttblog.com\">\u4e1a\u4f59\u8349<\/a>\uff1a &raquo; <a href=\"https:\/\/www.xttblog.com\/?p=4656\">CPU\u98d9\u9ad8\uff0c\u9891\u7e41GC\uff0c\u600e\u4e48\u6392\u67e5\uff1f<\/a><\/p><!-- <div class=\"bd-reward-stl\"><button id=\"bdRewardBtn\"><span><\/span><\/button><\/div> -->","protected":false},"excerpt":{"rendered":"<p>\u5904\u7406\u8fc7\u7ebf\u4e0a\u95ee\u9898\u7684\u540c\u5b66\u57fa\u672c\u4e0a\u90fd\u4f1a\u9047\u5230\u7cfb\u7edf\u7a81\u7136\u8fd0\u884c\u7f13\u6162\uff0cCPU 100%\uff0c\u4ee5\u53caFull GC\u6b21\u6570\u8fc7\u591a\u7684\u95ee\u9898\u3002\u5f53\u7136\uff0c [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[201,328,945,200,1744],"class_list":["post-4656","post","type-post","status-publish","format-standard","hentry","category-java","tag-dump","tag-gc","tag-jstack","tag-useparallelgc"],"_links":{"self":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/4656","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4656"}],"version-history":[{"count":1,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/4656\/revisions"}],"predecessor-version":[{"id":4657,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/4656\/revisions\/4657"}],"wp:attachment":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4656"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4656"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4656"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}