{"id":10020767,"date":"2025-04-24T21:50:58","date_gmt":"2025-04-24T13:50:58","guid":{"rendered":"https:\/\/itmax.cn\/?p=10020767"},"modified":"2025-04-24T21:50:58","modified_gmt":"2025-04-24T13:50:58","slug":"full-gc-%e9%a2%91%e7%8e%87%e4%bc%98%e5%8c%96%e5%ae%9e%e6%88%98","status":"publish","type":"post","link":"https:\/\/itmax.cn\/?p=10020767","title":{"rendered":"Full GC \u9891\u7387\u4f18\u5316\u5b9e\u6218"},"content":{"rendered":"<p>\u4f5c\u8005\uff1avivo \u4e92\u8054\u7f51\u670d\u52a1\u5668\u56e2\u961f- Li Gang<\/p>\n<p>\u672c\u6587\u4ecb\u7ecd\u4e86\u6e38\u620f\u4e1a\u52a1\u4f7f\u7528MAT\u548cGC\u65e5\u5fd7\u7b49\u5de5\u5177\u5bf9 Full GC\u9891\u7387\u8fdb\u884c\u4f18\u5316\u7684\u8fc7\u7a0b\u3002<\/p>\n<h2>\u4e00\u3001\u80cc\u666f<\/h2>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477584\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\"><\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477585\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u6e38\u620f\u4e1a\u52a1\u9762\u5bf9\u7528\u6237\u7aef\u7684\u67d0\u4e2a\u5de5\u7a0b\uff0c\u6bcf\u5929Full GC\u9891\u7387\u8fbe\u5230120\u6b21\uff0c\u4e1a\u52a1\u9ad8\u5cf0\u671f\u6bcf7\u5206\u949f\u5c31\u4f1a\u6709\u4e00\u6b21Full GC\u3002\u4e3a\u4e86\u907f\u514d\u60c5\u51b5\u6301\u7eed\u53d8\u5dee\uff0c\u6700\u5927\u7a0b\u5ea6\u51cf\u5c11\u5bf9\u7cfb\u7edf\u54cd\u5e94\u65f6\u95f4\u7684\u8d1f\u9762\u5f71\u54cd\uff0c\u9700\u8981\u5bf9\u8be5\u5de5\u7a0b\u7684Full GC\u9891\u7387\u8fdb\u884c\u4f18\u5316\u3002<\/p>\n<p>\u8be5\u9879\u76eeJDK\u7248\u672c\u4e3a1.8\uff0c\u8001\u5e74\u4ee3\u4f7f\u7528CMS\u4f5c\u4e3a\u5783\u573e\u56de\u6536\u5668\uff0c\u4f18\u5316\u524d\u7684\u90e8\u5206\u542f\u52a8\u53c2\u6570\u5982\u4e0b\uff1a<\/p>\n<pre><code>-Xms4608M -Xmx4608M -Xmn2048M -XX:MetaspaceSize=320M -XX:+UseConcMarkSweepGC -XX:CMSInitiatingOccupancyFraction=92 -XX:+UseCMSInitiatingOccupancyOnly\n<\/code><\/pre>\n<h2>\u4e8c\u3001\u5de5\u5177\u4ecb\u7ecd<\/h2>\n<p>\u5728\u672c\u6b21\u4f18\u5316\u8fc7\u7a0b\u4e2d\uff0c\u6211\u4eec\u4e3b\u8981\u4f7f\u7528\u4e86MAT\u548cGC\u65e5\u5fd7\u4f5c\u4e3a\u6392\u67e5\u5de5\u5177\u3002MAT\u662f\u4e00\u4e2a\u529f\u80fd\u5f3a\u5927\u7684\u5185\u5b58\u5206\u6790\u5de5\u5177\uff0c\u800cGC\u65e5\u5fd7\u5219\u7528\u4e8e\u8bb0\u5f55Java\u865a\u62df\u673a\u4e2d\u7684\u5783\u573e\u56de\u6536\u884c\u4e3a\u548c\u5185\u5b58\u60c5\u51b5\u3002\u8fd9\u4e24\u8005\u7ed3\u5408\u8d77\u6765\uff0c\u80fd\u591f\u5e2e\u52a9\u5f00\u53d1\u4eba\u5458\u6df1\u5165\u5206\u6790\u7a0b\u5e8f\u7684\u5185\u5b58\u4f7f\u7528\u60c5\u51b5\uff0c\u5e76\u8fdb\u884c\u76f8\u5e94\u7684\u4f18\u5316\u3002\u4e0b\u6587\u5c06\u8be6\u7ec6\u7684\u4ecb\u7ecd\u8fd9\u4e24\u79cd\u5de5\u5177\u7684\u4f7f\u7528\u65b9\u6cd5\uff0c\u4ee5\u53ca\u5bf9\u5e94\u7684\u4f18\u5316\u6848\u4f8b\u3002<\/p>\n<h3>2.1 MAT\uff08Memory Analyzer Tool\uff09<\/h3>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477586\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>Eclipse Memory Analyzer Tool\uff08MAT\uff09\u662f\u4e00\u4e2a\u5f00\u6e90\u7684Java\u5806\u8f6c\u50a8\u5206\u6790\u5de5\u5177\u3002\u5b83\u65e8\u5728\u5e2e\u52a9\u5f00\u53d1\u4eba\u5458\u8bc6\u522b\u548c\u6d88\u9664Java\u5806\u4e2d\u7684\u5185\u5b58\u6cc4\u6f0f\u548c\u4f18\u5316\u5185\u5b58\u4f7f\u7528\u3002MAT\u5141\u8bb8\u7528\u6237\u5206\u6790Java\u5806\u8f6c\u50a8\u6587\u4ef6\uff0c\u8bc6\u522b\u5bf9\u8c61\u7684\u5185\u5b58\u5360\u7528\u60c5\u51b5\uff0c\u67e5\u627e\u6f5c\u5728\u7684\u5185\u5b58\u6cc4\u6f0f\u548c\u5197\u4f59\u5bf9\u8c61\uff0c\u4ee5\u4fbf\u6267\u884c\u4e00\u4e9b\u5185\u5b58\u4f18\u5316\u3002<\/p>\n<p>\u4f7f\u7528MAT\u6253\u5f00dump\u6587\u4ef6\u540e\uff0c\u9996\u5148\u8fdb\u5165\u7684\u662f\u4e0a\u56fe\u9875\u9762\uff0c\u6b64\u9875\u9762\u4f1a\u663e\u793adump\u5305\u7684\u7f29\u7565\u6982\u89c8\u4fe1\u606f\uff0c\u5305\u62ec\u5806\u5927\u5c0f\uff0c\u7c7b\u6570\u91cf\uff0c\u5bf9\u8c61\u6570\u91cf\u7b49\u4fe1\u606f\u3002\u5176\u4e2d\u7684Biggest Objects By Retained Size\u548cLeak Suspects\u5728\u95ee\u9898\u660e\u663e\u65f6\u4f1a\u6bd4\u8f83\u6709\u7528\uff0c\u4f46\u5bf9\u76f8\u5bf9\u590d\u6742\u7684\u95ee\u9898\u6765\u8bf4\u5e2e\u52a9\u4e0d\u5927\u3002\u7b14\u8005\u6bd4\u8f83\u5e38\u7528\u7684\u662f\u4e0b\u9762\u8fd9\u51e0\u4e2a\u529f\u80fd\uff0c\u4e0b\u6587\u5c06\u4f9d\u6b21\u4ecb\u7ecd\uff1a<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477587\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<h4>2.1.1 Dominator Tree<\/h4>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477588\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p><strong>\uff081\uff09\u529f\u80fd<\/strong><\/p>\n<p>\u5c55\u793a\u5bf9\u8c61\u7684\u652f\u914d\u5173\u7cfb\u3002\u5bf9\u8c61A\u652f\u914d\u5bf9\u8c61B\u4ee3\u8868\u4eceGC Root\uff08\u4e5f\u4e0d\u4e00\u5b9a\u662fGC ROOT\uff0c\u4e5f\u53ef\u4ee5\u662funreachable\u7684\u8d77\u70b9\uff09\u8fbe\u5230\u5bf9\u8c61B\u7684\u6240\u6709\u8def\u5f84\u90fd\u5fc5\u987b\u7ecf\u8fc7\u5bf9\u8c61A\uff0c\u8fd9\u4e5f\u610f\u5473\u7740\u5bf9\u8c61A\u88ab\u5783\u573e\u56de\u6536\u540e\uff0c\u5bf9\u8c61B\u4e5f\u4f1a\u88ab\u56de\u6536\u3002<\/p>\n<p>\u8fd9\u4e2a\u529f\u80fd\u76f8\u8f83\u4e8e\u4e0b\u9762\u7684Histogram\u66f4\u5f3a\u8c03\u5bf9\u8c61\u7684\u5f15\u7528\u5173\u7cfb\uff0c\u6b64\u5916\u8fd8\u53ef\u4ee5\u901a\u8fc7Group By Class\/Group By Package\/Group By ClassLoader\u6765\u8fdb\u4e00\u6b65\u7684\u805a\u5408\u5bf9\u8c61\u3002<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477589\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>MAT\u7684\u5404\u79cd\u56fe\u6807\u4e2d\u4f1a\u9891\u7e41\u7684\u51fa\u73b0Shallow Heap Size\u548cRetained Heap Size\u8fd9\u4e24\u4e2a\u540d\u8bcd\uff0c\u5176\u542b\u4e49\u5982\u4e0b\uff1a<\/p>\n<ul>\n<li><strong>Shallow Heap Size<\/strong>\uff1a\u8fd9\u4e2a\u5bf9\u8c61\u81ea\u8eab\u5728\u5806\u4e2d\u7684\u5927\u5c0f<\/li>\n<li><strong>Retained Heap Size<\/strong>\uff1a\u8fd9\u4e2a\u5bf9\u8c61\u88ab\u5783\u573e\u56de\u6536\u540e\u4f1a\u91ca\u653e\u7684\u5806\u5185\u5b58\u5927\u5c0f<\/li>\n<\/ul>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477590\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u4e0a\u56fe\u4e2d\uff0c\u60c5\u51b51\u91cc\u5bf9\u8c61A\u7684Retained Heap Size = A\u7684Shallow Heap Size + B\u7684Shallow Heap Size +C\u7684Shallow Heap Size\uff0c\u60c5\u51b52\u91cc\u5bf9\u8c61A\u7684Retained Heap Size = A\u7684Shallow Heap Size + B\u7684Shallow Heap Size\u3002<\/p>\n<p><strong>\uff082\uff09\u4f7f\u7528\u65b9\u6cd5<\/strong><\/p>\n<p>\u2460\u4e0a\u56fe\u4e3aGroup By Class\u7684dominator tree\u3002\u521a\u6253\u5f00dominator tree\u65f6\u9ed8\u8ba4\u662f\u4e0d\u8fdb\u884cgroup\u7684\uff0c\u6b64\u65f6\u53ef\u4ee5\u6392\u67e5\u5355\u4e2a\u5927\u5bf9\u8c61\uff0c\u6392\u67e5\u5b8c\u5355\u4e2a\u5927\u5bf9\u8c61\u540e\uff0c\u9700\u8981\u5c06\u5bf9\u8c61Group\u4e00\u4e0b\u624d\u80fd\u8fdb\u884c\u4e0b\u4e00\u6b65\u7684\u6392\u67e5\u3002<\/p>\n<p>\u2461 \u4ece\u4e0a\u56fe\u53ef\u4ee5\u770b\u51fa\uff0c\u8fd9\u4e2a\u5806\u5185\u7684\u5bf9\u8c61\u5185\u5b58\u5360\u7528\u6bd4\u8f83\u5206\u6563\uff0c\u8bf4\u660e\u5bfc\u81f4\u95ee\u9898\u7684\u539f\u56e0\u53ef\u80fd\u4e0d\u6b62\u4e00\u4e2a\uff0c\u8fd9\u79cd\u60c5\u51b5\u4e0b\u53ea\u80fd\u7ed3\u5408\u81ea\u8eab\u4e1a\u52a1\u9010\u4e2a\u6392\u67e5\u5185\u5b58\u5360\u7528\u6392\u5728\u524d\u9762\u7684\u5bf9\u8c61\u3002<\/p>\n<p>\u2462 \u5bf9\u8fd9\u4e9b\u53ef\u7591\u7684\u5bf9\u8c61\uff0c\u53f3\u952e\u7c7b\uff0c\u9009\u62e9List objects \u2192 with outgoing references\u5c55\u5f00\u5bf9\u8c61\u5217\u8868\uff0c\u67e5\u770b\u8fd9\u7c7b\u5bf9\u8c61\u5177\u4f53\u5b58\u4e86\u4ec0\u4e48\uff0c\u5224\u65ad\u8fd9\u4e9b\u5bf9\u8c61\u7684\u503c\u662f\u5426\u53ef\u4ee5\u518d\u5206\u7c7b\u3002<\/p>\n<p>\u2463 \u6839\u636e\u5bf9\u8c61\u7684\u503c\uff0c\u5224\u65ad\u5bf9\u8c61\u7684\u4e1a\u52a1\u542b\u4e49\uff0c\u786e\u5b9a\u662f\u54ea\u6bb5\u4ee3\u7801\u521b\u5efa\u7684\u5bf9\u8c61\u3002<\/p>\n<p>\u2464 \u7ed3\u5408\u4ee3\u7801\uff0c\u601d\u8003\u8fd9\u7c7b\u5bf9\u8c61\u662f\u5728\u65b0\u751f\u4ee3\u8fd8\u662f\u8001\u5e74\u4ee3\uff0c\u5982\u679c\u80fd\u786e\u5b9a\u90fd\u5728\u65b0\u751f\u4ee3\uff0c\u90a3\u8fd9\u4e9b\u5bf9\u8c61\u4e00\u822c\u4e0d\u4f1a\u5bfc\u81f4\u8001\u5e74\u4ee3\u5feb\u901f\u589e\u957f\u3002<\/p>\n<p>\u2465\u5982\u679c\u5728\u8001\u5e74\u4ee3\uff0c\u9700\u8981\u786e\u5b9a\u5176\u662f\u600e\u4e48\u4ece\u65b0\u751f\u4ee3\u664b\u5347\u7684\uff0c\u5185\u5b58\u5360\u7528\u662f\u5426\u6709\u4e0a\u9650\uff0c\u4e0a\u9650\u662f\u591a\u5c11\uff0c\u4e00\u822c\u591a\u957f\u65f6\u95f4\u80fd\u8fbe\u5230\u4e0a\u9650\uff0c\u518d\u786e\u5b9a\u6709\u6ca1\u6709\u95ee\u9898\u3002<\/p>\n<h4>2.1.2 Histogram<\/h4>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477591\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p><strong>\u529f\u80fd<\/strong><\/p>\n<p>histogram\u53ef\u4ee5\u663e\u793a\u51fa\u5404\u7c7b\u5bf9\u8c61\u7684Shallow Heap Size\u548cRetained Heap Size\uff0cRetained Heap Size\u9ed8\u8ba4\u4e0d\u5c55\u793a\uff0c\u9700\u8981\u70b9\u51fb\u83dc\u5355\u680f\u7684Calculate Retained Size\u8fdb\u884c\u8ba1\u7b97\uff0c\u5806\u8f83\u5927\u65f6\u8ba1\u7b97\u8017\u65f6\u8f83\u957f\u3002<\/p>\n<p>\u8fd9\u5f20\u8868\u4e00\u822c\u548cDominator Tree\u7ed3\u5408\u4f7f\u7528\uff0c\u6211\u4eec\u80fd\u770b\u5230char[]\u5360\u7528\u4e86\u8f83\u5927\u7684\u5185\u5b58\uff0c\u4f46\u7531\u4e8eDominator Tree\u91cc\u805a\u5408\u597d\u7684char[]\u90fd\u662f\u9876\u5c42\u652f\u914d\u8005\uff0c\u4e0a\u5c42\u4e0d\u4f1a\u518d\u6709\u5f15\u7528\uff0c\u6709\u65f6\u65e0\u6cd5\u76f4\u63a5\u786e\u5b9a\u8fd9\u4e9b\u5bf9\u8c61\u66fe\u7ecf\u88ab\u8c01\u6301\u6709\u8fc7\uff0c\u8fd9\u65f6\u53ef\u4ee5\u901a\u8fc7Histogram\u67e5\u770b\u540c\u7c7b\u5bf9\u8c61\uff0c\u627e\u5230\u76f8\u4f3c\u7684\u5e76\u4e14reachable\u7684\u5bf9\u8c61\u6765\u786e\u5b9a\u8fd9\u7c7b\u5bf9\u8c61\u662f\u8c01\u521b\u5efa\u7684\u3002\u4f46\u662f\u8fd9\u4e00\u6b65\u5176\u5b9e\u53ef\u4ee5\u901a\u8fc7oql\u89e3\u51b3\uff0c\u6240\u4ee5\u8fd9\u5f20\u8868\u5728\u6392\u67e5\u8fc7\u7a0b\u4e2d\u7684\u4f7f\u7528\u7387\u5176\u5b9e\u6ca1\u6709Histogram\u9ad8\u3002<\/p>\n<h4>2.1.3 OQL<\/h4>\n<p><strong>\u529f\u80fd<\/strong><\/p>\n<p>MAT\u63d0\u4f9b\u7684\u4e00\u79cd\u7c7b\u4f3cSQL\u7684\u67e5\u8be2\u8bed\u53e5\uff0c\u53ef\u4ee5\u5bf9\u5bf9\u8c61\u8fdb\u884c\u8fc7\u6ee4\u3002\u8fd9\u7bc7\u5b98\u65b9\u6587\u7ae0\u91cc\u7ed9\u4e86\u5f88\u591a\u67e5\u8be2\u8bed\u53e5\u6837\u4f8b\uff1a<a href=\"https:\/\/link.segmentfault.com\/?enc=bjtsMjCmRAjYATYFWpJQQQ%3D%3D.qAvConUo77EB%2FJkHAAVpXn9jkfJvRThcewCgBCE%2FLrJnOayJQ%2FaUrJbf2ZIXX5Lz\" rel=\"nofollow noopener noreferrer\" target=\"_blank\">https:\/\/wiki.eclipse.org\/MemoryAnalyzer\/OQL<\/a>\uff0c\u8fd9\u91cc\u5c31\u7b80\u5355\u5217\u4e00\u4e9b\u7b14\u8005\u6392\u67e5\u8fc7\u7a0b\u4e2d\u7528\u8fc7\u7684\u8bed\u53e5\uff0c\u4e0d\u518d\u8d58\u8ff0\uff1a<\/p>\n<pre><code>\/\/ \u5b57\u7b26\u4e32\u6a21\u7cca\u5339\u914d\nSELECT * FROM char[] b where toString(b) LIKE &quot;.*traceId.*&quot;\n\/\/ \u67e5\u627e\u5730\u5740&gt;0x700000000\u7684\u5bf9\u8c61\nSELECT * FROM java.lang.Object t WHERE  toHex(t.@objectAddress) &gt;= &quot;0x700000000&quot;\n\/\/ \u67e5\u627e\u957f\u5ea6\u7b49\u4e8e73\u5e76\u4e14retained heap size&gt;1000B \u7684\u5bf9\u8c61\nSELECT * FROM java.lang.Object[] a where a.@length=73 and a.@retainedHeapSize&gt;1000\n\/\/ \u67e5\u627e\u957f\u5ea6\u7b49\u4e8e65536\u5e76\u4e14\u4e0a\u5c42\u6709\u5f15\u7528\u7684\u5bf9\u8c61\nSELECT * FROM char[] a where a.@length=65536 and (inbounds(a).size()&gt;0)\n<\/code><\/pre>\n<h3>2.2 GC\u65e5\u5fd7<\/h3>\n<p>GC\u65e5\u5fd7\u662f\u8bb0\u5f55Java\u865a\u62df\u673a\u4e2d\u5783\u573e\u56de\u6536\u6d3b\u52a8\u7684\u65e5\u5fd7\u6587\u4ef6\u3002\u5728GC\u65e5\u5fd7\u4e2d\uff0c\u53ef\u4ee5\u770b\u5230\u5305\u62ec\u5783\u573e\u56de\u6536\u7684\u65f6\u95f4\u3001\u7c7b\u578b\uff08\u5982\u65b0\u751f\u4ee3GC\u3001\u8001\u5e74\u4ee3GC\u7b49\uff09\u3001\u56de\u6536\u5468\u671f\u3001\u56de\u6536\u505c\u987f\u65f6\u95f4\u3001\u56de\u6536\u524d\u540e\u5806\u7684\u4f7f\u7528\u60c5\u51b5\u7b49\u4fe1\u606f\u3002GC\u65e5\u5fd7\u6253\u5370\u7684\u4fe1\u606f\u53ef\u4ee5\u901a\u8fc7\u4ee5\u4e0b\u542f\u52a8\u9879\u63a7\u5236\uff1a<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477592\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<h2>\u4e09\u3001 \u6848\u4f8b\u4ecb\u7ecd<\/h2>\n<p>\u5728\u8fd9\u7bc7\u6587\u7ae0\u4e2d\uff0c\u6211\u4eec\u5c06\u805a\u7126\u4e8e\u4e00\u4e9b\u5177\u4f53\u7684\u6848\u4f8b\uff0c\u6d89\u53ca\u5230\u5927\u91cf\u88abDubbo\u7684FutureAdapter\u5f15\u7528\u7684\u5bf9\u8c61\u3001Jackson\u7684BufferRecycler\u5bfc\u81f4\u7684\u5927\u91cfchar[65536]\u4ee5\u53ca\u5bf9\u8c61\u664b\u5347\u5e74\u9f84\u9608\u503c\u8fc7\u5c0f\u7b49\u95ee\u9898\u3002\u901a\u8fc7\u8fd9\u4e9b\u6848\u4f8b\uff0c\u6211\u4eec\u5c06\u63a2\u8ba8\u8fd9\u4e9b\u5177\u4f53\u95ee\u9898\u7684\u5f15\u8d77\u539f\u56e0\u4ee5\u53ca\u89e3\u51b3\u65b9\u6848\u3002<\/p>\n<h3>3.1 \u5927\u91cf\u88abDubbo\u7684FutureAdapter\u5f15\u7528\u7684\u5bf9\u8c61<\/h3>\n<p><strong>\uff081\uff09\u5206\u6790\u8fc7\u7a0b<\/strong><\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477593\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u4ece\u4e0a\u56fe\u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u770b\u5230dubbo FutureAdapter\u5360\u7528\u4e86230M\u5de6\u53f3\u7684\u5185\u5b58\uff0c\u524d\u9762\u7684PSWMS\u5bf9\u8c61\u867d\u7136\u4e5f\u5360\u7528\u4e86230M\u5de6\u53f3\u7684\u5185\u5b58\uff0c\u4f46\u8fd9\u662f\u4e1a\u52a1\u4f7f\u7528\u7684\u672c\u5730\u7f13\u5b58\u76f8\u5173\u5bf9\u8c61\uff0c\u5176\u5185\u5b58\u5360\u7528\u662f\u5728\u9884\u671f\u8303\u56f4\u5185\u7684\uff0c\u56e0\u6b64\u4f18\u5148\u5206\u6790FutureAdapter\u3002\u5148\u53f3\u952eList objects\u2192with outgoing references\u5c55\u5f00\u5bf9\u8c61\u5217\u8868\u3002<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477594\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u53d1\u73b0\u5176\u4e2d\u6709\u5927\u91cf\u5927\u5c0f\u51e0\u4e4e\u4e00\u81f4\u7684FutureAdapter\uff0c\u4e00\u4e2a\u5360\u7528\u5185\u5b58328KB\u5de6\u53f3\uff0c\u5927\u5c0f\u548c\u5185\u5bb9\u51e0\u4e4e\u4e00\u81f4\u7684\u5bf9\u8c61\u7ea6\u6709550\u591a\u4e2a\uff0c\u603b\u5171\u5360\u7528\u5185\u5b58200M\u5de6\u53f3\u3002<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477595\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>FutureAdapter\u88ab\u7528\u6765\u6267\u884cDubbo\u7684\u5f02\u6b65\u8c03\u7528\uff0c\u9879\u76ee\u4f7f\u7528\u7684dubbo\u7248\u672c\u4e3a2.7.18\u3002dubbo\u7684\u540c\u6b65\u8c03\u7528\u672c\u8d28\u4e0a\u662f\u4e00\u4e2a\u5f02\u6b65\u8f6c\u540c\u6b65\u7684\u8fc7\u7a0b\uff0c\u53d1\u8d77\u5f02\u6b65\u8c03\u7528\u5c06CompletableFuture\u5bf9\u8c61\u653e\u5230ThreadLocal\u7684FutureContext\u91cc\uff0c\u7136\u540e\u7acb\u523b\u8c03\u7528CompletableFuture.get\u65b9\u6cd5\u963b\u585e\u83b7\u53d6\u8fd4\u56de\u503c\uff0c\u83b7\u53d6\u5230\u8fd4\u56de\u503c\u540e\uff0cdubbo\u4e0d\u4f1a\u4e3b\u52a8\u6e05\u7406FutureContext\uff0c\u56e0\u6b64\u8be5\u7ebf\u7a0b\u7684ThreadLocal\u91cc\u4f1a\u6709\u4e00\u6761FutureContext\u2192 FutureAdapter\u2192Result\u7684\u5f15\u7528\uff0c\u5982\u4e0b\u56fe\uff1a<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477596\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u7136\u800c\uff0c\u90a3550\u591a\u4e2aFutureAdapter\u5747\u4e3a\u4e0d\u53ef\u8fbe\u5bf9\u8c61\uff0c\u610f\u5473\u7740\u5176\u4e0d\u88abThreadLocal\u5f15\u7528\uff0c\u5728\u4e0b\u6b21GC\u65f6\u4f1a\u88ab\u56de\u6536\uff0c\u4e0d\u8fc7\u6211\u4eec\u65e0\u6cd5\u76f4\u63a5\u786e\u5b9a\u8fd9\u4e9b\u5bf9\u8c61\u662f\u5728\u8001\u5e74\u4ee3\u8fd8\u662f\u65b0\u751f\u4ee3\uff0c\u6709\u53ef\u80fd\u8fd9\u4e9b\u5bf9\u8c61\u90fd\u5728\u65b0\u751f\u4ee3\uff0c\u4e0b\u6b21young gc\u65f6\u5c31\u4f1a\u88ab\u56de\u6536\uff0c\u4e0d\u4f1a\u664b\u5347\u5230\u8001\u5e74\u4ee3\uff0c\u66f4\u4e0d\u4f1a\u5bfc\u81f4\u8001\u5e74\u4ee3\u589e\u957f\u3002<\/p>\n<p>\u4f46\u7531\u4e8e\u8fd9\u4e2a\u5217\u8868\u91cc\u7684\u6570\u636e\u6709\u660e\u786e\u7684\u4e1a\u52a1\u542b\u4e49\uff0c\u53ef\u4ee5\u627e\u5230\u5bf9\u5e94\u7684\u4e1a\u52a1\u63a5\u53e3\uff0c\u6b64\u63a5\u53e3\u5355\u673a\u5cf0\u503cqps\u7ea6\u4e3a2\uff0c\u54cd\u5e94\u65f6\u95f4\u7ea6100ms\uff0c\u6bcf\u88ab\u8c03\u7528\u4e00\u6b21\uff0c\u5c31\u4f1a\u521b\u5efa\u4e00\u4e2a\u8be5\u5bf9\u8c61\u5217\u8868\uff0c\u6b64\u65f6\u8be5\u673a\u5668\u7684young gc\u9891\u7387\u7ea6\u4e3a10s\u4e00\u6b21\u3002\u5047\u8bbe\u8fd9\u4e9b\u5bf9\u8c61\u90fd\u5728\u65b0\u751f\u4ee3\u6ca1\u6709\u664b\u5347\u8001\u5e74\u4ee3\uff0c\u90a3\u4e48\u8fd9\u4e9b\u5bf9\u8c61\u5728\u65b0\u751f\u4ee3\u6700\u5927\u7684\u5b58\u6d3b\u6570\u91cf\u7ea6\u4e3a((\u63a5\u53e3\u54cd\u5e94\u65f6\u95f4 + \u4e24\u6b21young gc\u95f4\u9694) <em> \u5bf9\u8c61\u521b\u5efa\u901f\u5ea6) = (0.1s + 10s) <\/em> 2 \u2248 20\uff0c\u800c\u5806\u91cc\u6709550\u591a\u4e2a\uff0c\u5982\u679c\u8fd9\u4e9b\u5bf9\u8c61\u6ca1\u6709\u664b\u5347\u5230\u8001\u5e74\u4ee3\u7684\u8bdd\u6570\u91cf\u4e0a\u5bf9\u4e0d\u4e0a\uff0c\u6240\u4ee5\u53ef\u4ee5\u63a8\u6d4b\u51fa\u8fd9\u4e9b\u5bf9\u8c61\u5728\u8001\u5e74\u4ee3\u91cc\uff0c\u9700\u8981\u7b49\u4e0b\u6b21Full GC\u65f6\u624d\u4f1a\u88ab\u56de\u6536\u3002<\/p>\n<p>\u90a3\u4e48\u8fd9\u4e9b\u4e0d\u53ef\u8fbe\u7684FutureAdapter\u4e3a\u4ec0\u4e48\u4f1a\u5728\u8001\u5e74\u4ee3\uff1f\u6bcf\u6b21\u6267\u884cdubbo\u8c03\u7528\uff0cdubbo\u90fd\u4f1a\u7528\u8fd9\u6b21\u8c03\u7528\u7684FutureAdapter\u66ff\u6362\u6389\u4e0a\u6b21\u8c03\u7528\u65f6\u5b58\u5728FutureContext\u91cc\u7684FutureAdapter\uff0c\u4e0a\u6b21\u8c03\u7528\u7684FutureAdapter\u4e0d\u518d\u88abGC Root\u5f15\u7528\uff0c\u5728\u4e0b\u6b21GC\u65f6\u88ab\u56de\u6536\u3002\u5f53\u4e00\u4e2a\u7ebf\u7a0b\u76f8\u5bf9\u9891\u7e41\u7684\u6267\u884cdubbo\u8c03\u7528\u65f6\uff0cFutureAdapter\u4f1a\u88abyoung gc\u56de\u6536\uff0c\u4e0d\u4f1a\u664b\u5347\u5230\u8001\u5e74\u4ee3\u3002\u4f46\u5728\u672c\u4f8b\u4e2d\uff0c\u8be5dubbo\u8c03\u7528\u88ab\u653e\u5230\u4e86corePoolSize=150\uff0cmaxPoolSize=500\u7684\u4e1a\u52a1\u901a\u7528\u7ebf\u7a0b\u6c60\u4e2d\u6267\u884c\uff0c\u8be5\u7ebf\u7a0b\u6c60\u4f1a\u6267\u884c\u5176\u4ed6\u4e0d\u9700\u8981\u8c03\u7528dubbo\u670d\u52a1\u7684\u4efb\u52a1\uff0c\u5e76\u4e14\u8be5\u7ebf\u7a0b\u6c60\u7684\u4f7f\u7528\u7387\u5e76\u4e0d\u9ad8\uff0c\u8fd9\u5c31\u610f\u5473\u7740\u4e00\u4e2a\u7ebf\u7a0b\u8c03\u7528\u5b8cdubbo\u670d\u52a1\u540e\u53ef\u80fd\u8981\u8fc7\u4e00\u6bb5\u65f6\u95f4\u624d\u80fd\u6267\u884c\u4e0b\u4e00\u6b21dubbo\u8c03\u7528\u3002<\/p>\n<p>\u7531\u4e8e\u8fd9\u4e2a\u539f\u56e0\u5bfc\u81f4FutureAdapter\u88ab\u653e\u5165ThreadLocal\u540e\uff0c\u5728\u65b0\u751f\u4ee3\u505c\u7559\u8fc7\u957f\u65f6\u95f4\uff0c\u6700\u7ec8\u664b\u5347\u5230\u8001\u5e74\u4ee3\uff0c\u8fd9\u4e2a&#8221;\u8fc7\u957f\u65f6\u95f4&#8221;\u5bf9\u4e8e\u6b64\u9879\u76ee\u6765\u8bf4\u662f6\u6b21young gc\u7684\u95f4\u9694\u65f6\u957f\uff0c\u8fd9\u4e2a\u65f6\u957f\u7684\u83b7\u53d6\u65b9\u6cd5\u4f1a\u5728\u540e\u7eed\u8bf4\u660e\u3002<\/p>\n<p><strong>\uff082\uff09\u89e3\u51b3\u65b9\u6848<\/strong><\/p>\n<p>\u5bf9\u4e8e\u6b64\u4e1a\u52a1\u6765\u8bf4\uff0c\u8fd9\u4e2adubbo\u8c03\u7528\u53ef\u4ee5\u6539\u4e3a\u67e5\u8be2\u672c\u5730\u7f13\u5b58\uff0c\u76f4\u63a5\u89e3\u51b3\u4e86\u95ee\u9898\u3002\u9664\u6b64\u4e4b\u5916\u8fd8\u6709\u5176\u4ed6\u89e3\u51b3\u65b9\u6848\uff0c\u9700\u8981\u7ed3\u5408\u81ea\u8eab\u4e1a\u52a1\u9009\u62e9\u5408\u9002\u7684\u65b9\u6848\u3002<\/p>\n<ol>\n<li>\u76f4\u63a5\u4f7f\u7528dubbo\u7684\u5f02\u6b65\u8c03\u7528\uff0c\u800c\u4e0d\u662f\u5728\u4e0a\u5c42\u518d\u521b\u5efa\u4e00\u4e2a\u7ebf\u7a0b\u6c60\u6765\u8fdb\u884c\u8c03\u7528\u3002<\/li>\n<li>\u5408\u7406\u8bbe\u7f6e\u7ebf\u7a0b\u6c60\u7684\u5927\u5c0f\uff0c\u63d0\u9ad8\u7ebf\u7a0b\u7684\u5229\u7528\u7387\u3002<\/li>\n<li>\u5199\u4e00\u4e2aDubbo Filter\uff0c\u6bcf\u6b21\u540c\u6b65\u8c03\u7528\u5b8c\u540e\u6e05\u7406FutureContext\uff08\u5f71\u54cd\u9762\u53ef\u80fd\u8f83\u5927\uff0c\u9700\u81ea\u884c\u8bc4\u4f30\u98ce\u9669\uff09\u3002<\/li>\n<\/ol>\n<h3>3.2. Jackson\u7684BufferRecycler\u5bfc\u81f4\u7684\u5927\u91cfchar[65536]<\/h3>\n<p><strong>\uff081\uff09\u5206\u6790\u8fc7\u7a0b<\/strong><\/p>\n<p>\u4ecedominator tree\u4e2d\u6211\u4eec\u80fd\u770b\u5230char[]\u4e5f\u5360\u7528\u4e86\u76f8\u5f53\u5927\u7684\u4e00\u90e8\u5206\u5185\u5b58\uff0c\u5c55\u5f00char[]\uff0c\u53d1\u73b0\u5176\u4e2d\u5305\u542b\u5927\u91cf\u7684char[65536]\uff0c\u4f7f\u7528oql\u7edf\u8ba1\u5f97\u77e5\u4e0d\u88abgc root\u5f15\u7528\u7684\u67091600\u4e2a\uff0c\u5360\u7528\u5185\u5b58200M\u5de6\u53f3\uff0c\u88abgc root\u5f15\u7528\u7684\u6709500\u4e2a\uff0c\u8fd9\u79cdchar[65536]\u91cc\u5b58\u50a8\u7684\u6570\u636e\u5747\u4e3ahttp\u63a5\u53e3\u8fd4\u56de\u503c\u53cd\u5e8f\u5217\u5316\u540e\u7684\u5b57\u7b26\u3002\u5176\u88abgc root\u5f15\u7528\u65f6\u7684\u94fe\u8def\u5982\u4e0b\uff0c\u5747\u88abThreadLocal\u91cc\u7684BufferRecycler\u5f15\u7528\uff1a<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477597\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u5728Jackson\u5e93\u4e2d\uff0cBufferRecycler\u7684\u4e3b\u8981\u4f5c\u7528\u662f\u7ba1\u7406\u7f13\u51b2\u533a\u7684\u91cd\u7528\uff0c\u53ef\u4ee5\u51cf\u5c11\u9891\u7e41\u7684\u5185\u5b58\u5206\u914d\u548c\u91ca\u653e\uff0c\u4ece\u800c\u964d\u4f4e\u5783\u573e\u56de\u6536\u7684\u8d1f\u62c5\uff0c\u63d0\u9ad8\u6027\u80fd\u3002\u4f46\u4ece\u5806\u4e0a\u770b\uff0c\u8fd9\u4e9bchar\u6570\u7ec4\u91cc\u4e0d\u53ef\u8fbe\u7684\u6570\u91cf\u8fdc\u5927\u4e8e\u53ef\u8fbe\u7684\u6570\u91cf\uff081600:500\uff09\uff0c\u8bf4\u660e\u5176\u590d\u7528\u7387\u5e76\u4e0d\u9ad8\uff0c\u4e0e\u5176\u8bbe\u8ba1\u7684\u76ee\u6807\u4e0d\u7b26\uff0c\u9700\u8981\u67e5\u770b\u6e90\u7801\u624d\u80fd\u641e\u6e05\u539f\u56e0\u3002<\/p>\n<p>\u9879\u76ee\u4f7f\u7528jackson\u7684ObjectMapper.<\/p>\n<p>writeValueAsString()\u65b9\u6cd5\u5bf9http\u63a5\u53e3\u8fd4\u56de\u503c\u8fdb\u884c\u4e86\u53cd\u5e8f\u5217\u5316\uff0c\u4f7f\u7528\u7684Jackson\u7248\u672c\u4e3a2.10\uff0c\u8be5\u65b9\u6cd5\u5b8c\u6574\u7684\u6267\u884c\u6d41\u7a0b\u5982\u4e0b\u56fe\uff1a<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477598\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u7b80\u5355\u6765\u8bf4\uff0cjackson\u5728\u53cd\u5e8f\u5217\u5316\u65f6\uff0c\u4f1a\u5c06\u53cd\u5e8f\u5217\u5316\u7684\u7ed3\u679c\u5b58\u50a8\u5728\u591a\u6bb5char[]\u91cc\uff0c\u6bcf\u5f53\u6700\u540e\u4e00\u4e2achar[]\u7a7a\u95f4\u4e0d\u591f\u5b58\u653e\u7ed3\u679c\u65f6\uff0c\u5c31\u65b0\u5efa\u4e00\u4e2achar[]\uff0c\u5927\u5c0f\u4e3a\u6700\u540e\u4f7f\u7528\u7684char[]\u76841.5\u500d\uff0c\u4f46\u4e0d\u8d85\u8fc765536\uff0c\u53cd\u5e8f\u5217\u5316\u7ed3\u675f\u540e\u5c06char[]\u5217\u8868\u62fc\u63a5\u8d77\u6765\u5c31\u5f97\u5230\u4e86\u7ed3\u679c\uff0c\u7136\u540e\u7ebf\u7a0b\u4f1a\u5c06\u6700\u540e\u4f7f\u7528\u7684\u90a3\u4e2achar[]\u5b58\u653e\u5230ThreadLocal\u3002\u6b64\u7ebf\u7a0b\u4e0b\u6b21\u53cd\u5e8f\u5217\u5316\u65f6\uff0c\u4f1a\u4eceThreadLocal\u53d6\u51fa\u8fd9\u4e2achar[]\u8fdb\u884c\u590d\u7528\u3002\u8fd9\u6837\u7684\u4e00\u4e2a\u590d\u7528\u903b\u8f91\u4f1a\u6709\u4e00\u4e2a\u95ee\u9898\uff0c\u53c2\u8003\u4e0b\u56fe\uff1a<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477599\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u56fe\u4e2d\uff0c_segements\u662f\u5f53\u524d\u53cd\u5e8f\u5217\u5316\u4f7f\u7528\u8fc7\u7684char[]\u5217\u8868\uff0ccurrentSegement\u662f\u5f53\u524d\u6b63\u5728\u4f7f\u7528\u7684char[]\u3002\u4e00\u4e2achar[]\u7684\u5927\u5c0f\u6700\u5927\u4e3a65536\u3002\u5728\u7b2c\u4e8c\u6b21\u53cd\u5e8f\u5217\u5316\u5927\u5bf9\u8c61\u65f6\u81f3\u5c11\u4f1a\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u5927\u5c0f\u4e3a65536\u7684char[]\uff08\u4e0a\u4e00\u6b21\u7684char[]\u662f65536\uff0c\u518d\u521b\u5efa\u4e00\u4e2a\u65b0char[]\u5176\u5927\u5c0f\u4ecd\u4e0d\u80fd\u8d85\u8fc765536\uff09\u3002\u53ef\u4ee5\u770b\u5230\u5728\u7b2c\u4e00\u6b21\u53cd\u5e8f\u5217\u5316\u7ed3\u675f\u540e\u548c\u7b2c\u4e8c\u6b21\u53cd\u5e8f\u5217\u5316\u7ed3\u675f\u540e\uff0c\u867d\u7136ThreadLocal\u91cc\u5b58\u653e\u7684char[]\u5927\u5c0f\u90fd\u662f65536\uff0c\u4f46\u5176\u5b9e\u5b83\u4eec\u5df2\u7ecf\u4e0d\u662f\u540c\u4e00\u4e2a\u5bf9\u8c61\u4e86\u3002\u8fd9\u6837\u7684\u4e00\u4e2a\u66ff\u6362\u662f\u6ca1\u6709\u5fc5\u8981\u7684\uff0c\u5b8c\u5168\u53ef\u4ee5\u4e00\u76f4\u590d\u7528\u540c\u4e00\u4e2achar[]\u3002<\/p>\n<p>\u5f53\u4e1a\u52a1\u6240\u6709http\u63a5\u53e3\u7684\u8fd4\u56de\u503c\u90fd\u5927\u4e14\u6d41\u91cf\u4e5f\u5927\u65f6\uff0c\u6bcf\u6b21\u4fdd\u5b58\u5728ThreadLocal\u91cc\u7684char[65536]\u867d\u7136\u4f1a\u5728\u4e0b\u6b21\u53cd\u5e8f\u5217\u5316\u7ed3\u675f\u65f6\u88ab\u66ff\u6362\u5bfc\u81f4\u5176\u5931\u53bb\u5f15\u7528\uff0c\u4f46\u7531\u4e8e\u5176\u5728\u65b0\u751f\u4ee3\u53ea\u5b58\u6d3b\u4e86\u4e00\u6b21\u63a5\u53e3\u8bf7\u6c42\u7684\u65f6\u95f4\uff0c\u6240\u4ee5\u4e0d\u4f1a\u664b\u5347\u5230\u8001\u5e74\u4ee3\uff0c\u53ef\u4ee5\u88abyoung gc\u56de\u6536\u3002\u4f46\u662f\u6211\u4eec\u9879\u76ee\u7528\u6765\u5904\u7406http\u8bf7\u6c42\u7684\u7ebf\u7a0b\u6c60\u90fd\u662f\u540c\u4e00\u4e2a\uff0c\u8fd9\u4e9b\u63a5\u53e3\u7684\u8fd4\u56de\u503c\u53ea\u6709\u4e00\u90e8\u5206\u8d85\u8fc7\u4e8665536\uff0c\u5728\u5c0f\u4e8e\u7684\u65f6\u5019ThreadLocal\u91cc\u7684char[]\u4e0d\u4f1a\u88ab\u66ff\u6362\uff0c\u5f53\u8fd9\u4e2achar[]\u5728ThreadLocal\u91cc\u505c\u7559\u4e00\u6bb5\u65f6\u95f4\u540e\uff0c\u5c31\u4f1a\u664b\u5347\u5230\u8001\u5e74\u4ee3\uff0c\u4ece\u800c\u5bfc\u81f4\u8001\u5e74\u4ee3\u5185\u5b58\u589e\u957f\u3002<\/p>\n<p><strong>\uff082\uff09\u89e3\u51b3\u65b9\u6848<\/strong><\/p>\n<ol>\n<li>\n<p>\u5173\u95edJackson\u7684USE\/_THREAD\/_LOCAL_<\/p>\n<p>FOR\/_BUFFER\/_RECYCLING\uff0c\u5173\u95ed\u8be5\u5f00\u5173\u4f1a\u5728\u6bcf\u6b21\u53cd\u5e8f\u5217\u5316\u65f6\u521b\u5efa\u4e00\u4e2aBufferRecycler\uff0c\u800c\u4e0d\u662f\u590d\u7528ThreadLocal\u91cc\u7684BufferRecycler\uff0c\u8fd9\u6837\u53ef\u80fd\u5bfc\u81f4young gc\u9891\u7387\u63d0\u9ad8\u3002<\/p>\n<\/li>\n<li>\u5347\u7ea7Jackson\u7248\u672c\uff0c\u8bf7\u53c2\u8003\u6b64<a href=\"https:\/\/link.segmentfault.com\/?enc=u03TEX0naNVP1qEkG4MPYA%3D%3D.qMtRWZsGjQ5YekR14U3MUoEdOb13YxYrBu6VpnTUTDIhWRBHGolu6IZS%2F9CfwxYnRf0ZFGFC7yKF8XBSbiGUpQ%3D%3D\" rel=\"nofollow noopener noreferrer\" target=\"_blank\">issue<\/a>\uff0c2.17\u7248\u672c\u7684jackson\u5728\u8c03\u7528releaseByteBuffer\u65f6\u4f1a\u907f\u514d\u8f83\u5c0f\u6216\u8005\u76f8\u540c\u5927\u5c0f\u7684char\u6570\u7ec4\u66ff\u6362\u539f\u6709\u6570\u7ec4\u3002<\/li>\n<\/ol>\n<p>\u7531\u4e8e\u9879\u76ee\u4f7f\u7528\u7684jackson\u7248\u672c\u662f2.10\uff0c\u76f4\u63a5\u5347\u7ea7\u52302.17\u7684\u7248\u672c\u8de8\u5ea6\u8f83\u5927\uff0c\u53ef\u80fd\u5e26\u6765\u4e0d\u5fc5\u8981\u7684\u98ce\u9669\uff0c\u56e0\u6b64\u91c7\u7528\u4e86\u65b9\u68481\uff0c\u4e0a\u7ebf\u540e\uff0cyoung gc\u9891\u7387\u6ca1\u6709\u660e\u663e\u589e\u52a0\u3002\u65b9\u68482\u7684issue\u91cc\u6709\u63d0\u5230\u4f7f\u75282.16\u7248\u672c\u5f15\u5165\u7684RecyclerPool\u4ee3\u66ff\u57fa\u4e8eThreadLocal\u7684\u5b9e\u73b0\uff0c\u8fd9\u4e5f\u662f\u89e3\u51b3\u65b9\u6848\u4e4b\u4e00\u3002<\/p>\n<h3>3.3 \u5bf9\u8c61\u664b\u5347\u5e74\u9f84\u9608\u503c\u8fc7\u5c0f<\/h3>\n<p><strong>\uff081\uff09\u80cc\u666f\u77e5\u8bc6<\/strong><\/p>\n<p>java\u5bf9\u8c61\u4ece\u65b0\u751f\u4ee3\u664b\u5347\u5230\u8001\u5e74\u4ee3\u6709\u591a\u79cd\u539f\u56e0\uff0c\u5728\u672c\u9879\u76ee\u4e2d\uff0c\u5bf9\u8c61\u7684\u4e3b\u8981\u664b\u5347\u539f\u56e0\u662f\u5728\u65b0\u751f\u4ee3\u957f\u671f\u5b58\u6d3b\uff0c\u8fd9\u4e2a\u957f\u671f\u5177\u4f53\u662f\u591a\u4e45\u6709\u4ee5\u4e0b\u4e24\u4e2a\u5224\u65ad\u6761\u4ef6\uff1a<\/p>\n<ul>\n<li>\n<p><strong>\u5bf9\u8c61\u664b\u5347\u5e74\u9f84\u9608\u503c<\/strong>\uff1a<\/p>\n<p>\u53ef\u901a\u8fc7-XX:MaxTenuringThreshold\u542f\u52a8\u9879\u8fdb\u884c\u914d\u7f6e\uff0c\u5bf9\u4e8eCMS\uff0c\u9ed8\u8ba4\u503c\u662f6\u3002\u6b64\u53c2\u6570\u5b9a\u4e49\u4e86\u5bf9\u8c61\u5728\u5e74\u8f7b\u4ee3\u5b58\u6d3b\u7684\u6700\u5927\u5e74\u9f84\uff0c\u5982\u679c\u4e00\u4e2a\u5bf9\u8c61\u5728\u5e74\u8f7b\u4ee3\u7ecf\u8fc7N\u6b21GC\u540e\u4f9d\u7136\u5b58\u6d3b\uff0c\u5b83\u5c06\u4f1a\u88ab\u664b\u5347\u5230\u8001\u5e74\u4ee3\u3002<\/p>\n<\/li>\n<li>\n<p><strong>\u52a8\u6001\u5e74\u9f84\u5224\u5b9a<\/strong>\uff1a<\/p>\n<p>\u5728survivor\u533a\u4e2d\u5c0f\u4e8e\u6216\u7b49\u4e8e\u67d0\u5e74\u9f84\u7684\u7684\u6240\u6709\u5bf9\u8c61\u5927\u5c0f\u7684\u603b\u548c\u5927\u4e8esurvivor\u7a7a\u95f4\u7684\u4e00\u5b9a\u6bd4\u4f8b\u65f6\uff0c\u5927\u4e8e\u6216\u7b49\u4e8e\u8be5\u5e74\u9f84\u7684\u5bf9\u8c61\u5c31\u76f4\u63a5\u8fdb\u5165\u8001\u5e74\u4ee3\uff0c\u8fd9\u4e2a\u6bd4\u4f8b\u53ef\u4ee5\u901a\u8fc7-XX:TargetSurvivorRatio\u542f\u52a8\u9879\u63a7\u5236\uff0c\u9ed8\u8ba4\u503c\u4e3a50\uff0c\u4ee3\u886850%\u3002<\/p>\n<\/li>\n<\/ul>\n<p>\u4e00\u4e2a\u5bf9\u8c61\u7684\u5e74\u9f84\u6ee1\u8db3\u4e0a\u8ff0\u4e24\u4e2a\u6761\u4ef6\u4e4b\u4e00\u65f6\uff0c\u5c31\u4f1a\u664b\u5347\u5230\u8001\u5e74\u4ee3\uff0c\u5177\u4f53\u7684\u664b\u5347\u5e74\u9f84\u53ef\u4ee5\u901a\u8fc7\u5728\u542f\u52a8\u9879\u91cc\u6dfb\u52a0-XX:+PrintTenuringDistribution\u83b7\u53d6\uff0c\u6dfb\u52a0\u8be5\u53c2\u6570\u540e\u7684gc\u65e5\u5fd7\u5982\u4e0b\u56fe\uff1a<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477600\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u5176\u4e2d\u533a\u57df2\u7684(max 6)\u4ee3\u8868-XX:MaxTenuringThreshold\u542f\u52a8\u9879\u914d\u7f6e\u7684\u503c\uff0c\u4e5f\u5c31\u662f\u8bf4\u5bf9\u8c61\u5230\u8fbe\u8fd9\u4e2a\u5e74\u9f84\u4e00\u5b9a\u4f1a\u664b\u5347\uff0c\u800cnew threshold 6\u4ee3\u8868\u5bf9\u8c61\u5b9e\u9645\u664b\u5347\u7684\u5e74\u9f84\uff0c\u4e0a\u56fe\u4ee3\u8868\u8fd9\u6b21young gc\u56e0\u5bf9\u8c61\u5230\u8fbe\u5e74\u9f84\u9608\u503c\u4f1a\u5bfc\u81f49946864 bytes\u7684\u5bf9\u8c61\u664b\u5347\u3002<\/p>\n<p>\u533a\u57df1\u4ee3\u8868\u52a8\u6001\u5e74\u9f84\u5224\u5b9a\u6240\u9700\u7684\u7a7a\u95f4\u5927\u5c0f\uff0c\u4e5f\u5c31\u662f(survivor\u7a7a\u95f4\u5927\u5c0f x targetSurvivotRatio)\u3002\u6b64\u9879\u76ee\u5806\u7684\u5355\u4e2asurvivor\u7a7a\u95f4\u4e3a200M\uff0c\u6240\u4ee5\u53ea\u8981\u5728survivor\u533a\u4e2d\u5c0f\u4e8e\u6216\u7b49\u4e8e\u67d0\u5e74\u9f84\u7684\u6240\u6709\u5bf9\u8c61\u5927\u5c0f\u7684\u603b\u548c\u5927\u4e8e200Mx50%\uff0c\u5927\u4e8e\u6216\u7b49\u4e8e\u8be5\u5e74\u9f84\u7684\u5bf9\u8c61\u5c31\u4f1a\u664b\u5347\uff0c\u3002<\/p>\n<p>\u800c\u4e0b\u56fe\u7684\u5bf9\u8c61\u662f\u56e0\u4e3a\u52a8\u6001\u5e74\u9f84\u5224\u5b9a\u624d\u664b\u5347\u7684\uff0c\u8fd9\u6b21young gc\u56e0\u52a8\u6001\u5e74\u9f84\u5224\u5b9a\u4f1a\u5bfc\u81f438660424 bytes\u7684\u5bf9\u8c61\u664b\u5347\uff1a<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477601\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p><strong>\uff082\uff09\u5206\u6790\u8fc7\u7a0b<\/strong><\/p>\n<p><strong>\u4f18\u5316\u524d+\u8c03\u53c2\u524d\uff1a<\/strong><\/p>\n<p>\u5728\u8fdb\u884cdubbo\u548cjackson\u4ee5\u53ca\u5176\u4ed6\u4e1a\u52a1\u4ee3\u7801\u4e0a\u7684\u4f18\u5316\u524d\uff0c\u6211\u4eec\u4fdd\u5b58\u4e86\u5f53\u65f6\u7684gc\u65e5\u5fd7\uff0c\u53ef\u4ee5\u770b\u5230\u5927\u90e8\u5206\u5bf9\u8c61\u90fd\u662f\u56e0\u4e3a\u5e74\u9f84\u5230\u8fbe6\u664b\u5347\u7684\uff0c\u6bcf\u6b21young gc\u7ea6\u670910M~16M\u5de6\u53f3\u7684\u5bf9\u8c61\u664b\u5347\uff0c\u663e\u7136\u5bf9\u8c61\u7684\u664b\u5347\u5e74\u9f84\u9608\u503c\u592a\u5c0f\uff0c\u9700\u8981\u8c03\u5927\u3002<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477602\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p><strong>\u4f18\u5316\u540e+\u8c03\u53c2\u524d\uff1a<\/strong><\/p>\n<p>\u5728\u8c03\u6574 JVM \u53c2\u6570\u4e4b\u524d\uff0c\u6211\u4eec\u51b3\u5b9a\u5148\u7740\u624b\u8fdb\u884c\u4e1a\u52a1\u4e0a\u7684\u4f18\u5316\u3002\u56e0\u4e3a\u76f4\u63a5\u8fdb\u884c\u53c2\u6570\u8c03\u6574\u53ef\u80fd\u4f1a\u6cbb\u6807\u4e0d\u6cbb\u672c\uff0c\u65e0\u6cd5\u6d88\u9664\u6f5c\u5728\u7684\u9690\u60a3\u3002\u5728\u5b8c\u6210\u4e1a\u52a1\u4ee3\u7801\u4e0a\u7684\u4f18\u5316\u540e\uff0c\u53ef\u4ee5\u770b\u5230\u6b64\u65f6\u7531\u4e8e\u5e74\u9f84\u8fbe\u52306\u8fd9\u4e00\u9608\u503c\u664b\u5347\u7684\u5bf9\u8c61\u5927\u5c0f\u4ece\u6700\u5f00\u59cb\u768410M~16M\u964d\u4e3a\u4e864M\u4ee5\u4e0b\uff0c\u610f\u5473\u7740\u5728\u65b0\u751f\u4ee3\u957f\u671f\u5b58\u6d3b\u7684\u5bf9\u8c61\u6570\u91cf\u660e\u663e\u51cf\u5c11\u4e86\uff0c\u4f46\u4ecd\u7136\u6709\u4f18\u5316\u7a7a\u95f4\u3002<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477603\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p><strong>\uff083\uff09\u89e3\u51b3\u65b9\u6848<\/strong><\/p>\n<p>\u5728\u5b8c\u6210\u4e1a\u52a1\u4ee3\u7801\u4e0a\u7684\u4f18\u5316\u540e\uff0c\u6211\u4eec\u5bf9 JVM \u53c2\u6570\u8fdb\u884c\u4e86\u8c03\u6574\u3002\u5c06-XX:MaxTenuringThreshold\u53c2\u6570\u6539\u4e3a15\uff0c-XX:TargetSurvivorRatio\u6539\u4e3a75%\uff08\u5b9e\u9645\u4e0a\uff0c\u901a\u8fc7\u8c03\u53c2\u540e\u7684gc\u65e5\u5fd7\u6211\u4eec\u80fd\u786e\u5b9a\u5bf9\u4e8e\u8fd9\u4e2a\u9879\u76ee\u6765\u8bf4\uff0c50%\u4e5f\u5df2\u7ecf\u591f\u7528\uff0c\u56e0\u4e3a\u5e74\u9f841\u523015\u7684\u5bf9\u8c61\u5360\u7528\u7684\u603b\u5185\u5b58\u53ea\u670938M\u5de6\u53f3\uff0c\u8fdc\u8fdc\u5c0f\u4e8e\u5355\u4e2asurvivor\u7a7a\u95f4\u768450%\uff09\uff0c\u4ee5\u5ef6\u957f\u5bf9\u8c61\u5728\u65b0\u751f\u4ee3\u7684\u5b58\u6d3b\u65f6\u95f4\u3002\u6211\u4eec\u53ef\u4ee5\u89c2\u5bdf\u5230\uff0c\u5c3d\u7ba1\u4f1a\u6709\u4e00\u4e9b\u5bf9\u8c61\u5b58\u6d3b\u5230\u5e74\u9f8415\u7684\u9608\u503c\u624d\u664b\u5347\uff0c\u4f46\u662f\u8fd9\u90e8\u5206\u5bf9\u8c61\u7684\u603b\u5927\u5c0f\u53d8\u5c0f\u4e86\uff0c\u5927\u90e8\u5206\u60c5\u51b5\u4e0b\u90fd\u662f\u5c0f\u4e8e2M\u3002\u8fd9\u90e8\u5206\u5bf9\u8c61\u901a\u8fc7\u6dfb\u52a0\u76d1\u63a7\u7684\u65b9\u5f0f\u5224\u65ad\u5927\u6982\u7387\u662f\u88ab\u79fb\u9664\uff08\u5927\u5c0f\u4e0d\u8db3\u88ab\u6dd8\u6c70\uff0c\u8fc7\u671f\u7b49\u539f\u56e0\uff09\u7684caffeine\u672c\u5730\u7f13\u5b58\u3002<\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477604\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u5728\u7ecf\u8fc7\u4e0a\u8ff0\u4e00\u7cfb\u5217\u4f18\u5316\u63aa\u65bd\u4ee5\u53ca\u4e00\u4e9b\u5176\u4ed6\u95ee\u9898\u7684\u4fee\u590d\u540e\uff0c\u8be5\u5de5\u7a0b\u7684 Full GC \u9891\u7387\u4ece\u6700\u521d\u7684\u6bcf\u5929 120 \u6b21\uff0c\u603b\u8017\u65f6 1 \u5206\u949f\u5230 1.5 \u5206\u949f\uff0c\u6210\u529f\u964d\u4f4e\u5230\u6bcf\u5929\u7ea6 30 \u6b21\u5de6\u53f3\uff0c\u603b\u8017\u65f6\u63a7\u5236\u5728 15 \u79d2\u5230 25 \u79d2\u4e4b\u95f4\u3002<\/p>\n<p><strong>\u2460 GC\u6b21\u6570\u4f18\u5316\u66f2\u7ebf<\/strong><\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477605\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477606\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p><strong>\u2461 GC\u603b\u8017\u65f6\u4f18\u5316\u66f2\u7ebf<\/strong><\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477607\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p><img decoding=\"async\"   referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000046477608\" alt=\"\u56fe\u7247\" title=\"\u56fe\u7247\" loading=\"lazy\"><\/p>\n<p>\u603b\u7684\u6765\u8bf4\uff0c\u8fdb\u884cGC\u4f18\u5316\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u5de5\u5177\u5206\u6790\u5f53\u524d\u5185\u5b58\/GC\u60c5\u51b5\uff1a<\/p>\n<ol>\n<li>\u5148\u7528jamp\u751f\u6210dump\u6587\u4ef6\uff0c\u518d\u4f7f\u7528MAT\u8fdb\u884c\u5206\u6790\uff0c\u627e\u5230\u53ef\u80fd\u5f15\u53d1\u95ee\u9898\u7684\u5bf9\u8c61\u3002<\/li>\n<li>\u4f7f\u7528\u5185\u5b58\u5206\u914d\u706b\u7130\u56fe\u627e\u5230\u54ea\u4e9b\u4ee3\u7801\u5728\u9891\u7e41\u7684\u5206\u914d\u5185\u5b58\u3002<\/li>\n<li>\u4f7f\u7528GC\u65e5\u5fd7\u5206\u6790GC\u60c5\u51b5\uff0c\u4e86\u89e3GC\u9891\u7387\/\u89e6\u53d1GC\u7684\u539f\u56e0\u7b49\u4fe1\u606f\u3002<\/li>\n<\/ol>\n<p>\u4f7f\u7528\u8fd9\u4e9b\u5de5\u5177\u627e\u5230\u95ee\u9898\u540e\uff0c\u53ef\u4ee5\u4fee\u6539\u5bf9\u5e94\u7684\u4e1a\u52a1\u4ee3\u7801\u6216\u8005\u8c03\u6574JVM\u76f8\u5173\u53c2\u6570\uff0c\u4ee5\u4f18\u5316Full GC\u9891\u7387\u3002<\/p>\n<p><a href=\"https:\/\/segmentfault.com\/a\/1190000046477582\">https:\/\/segmentfault.com\/a\/1190000046477582<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4f5c\u8005\uff1avivo \u4e92\u8054\u7f51\u670d\u52a1\u5668\u56e2\u961f- Li Gang \u672c\u6587\u4ecb\u7ecd\u4e86\u6e38\u620f\u4e1a\u52a1\u4f7f\u7528MAT\u548cGC\u65e5\u5fd7\u7b49\u5de5\u5177\u5bf9 Full  [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[4],"tags":[],"class_list":["post-10020767","post","type-post","status-publish","format-standard","hentry","category-share"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10020767","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10020767"}],"version-history":[{"count":0,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10020767\/revisions"}],"wp:attachment":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10020767"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10020767"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10020767"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}