{"id":116,"date":"2023-02-18T10:16:35","date_gmt":"2023-02-18T02:16:35","guid":{"rendered":"https:\/\/www.appblog.cn\/?p=116"},"modified":"2023-02-18T10:18:13","modified_gmt":"2023-02-18T02:18:13","slug":"jvm-younggen-8-1-1-reason","status":"publish","type":"post","link":"https:\/\/www.appblog.cn\/index.php\/2023\/02\/18\/jvm-younggen-8-1-1-reason\/","title":{"rendered":"JVM \u65b0\u751f\u4ee3 8:1:1 \u539f\u56e0"},"content":{"rendered":"

GC\u662f\u7edf\u8ba1\u5b66\u6d4b\u7b97\u51fa\u5f53\u5185\u5b58\u4f7f\u7528\u8d85\u8fc798%\u4ee5\u4e0a\u65f6\uff0c\u5185\u5b58\u5c31\u5e94\u8be5\u88abminor gc<\/code>\u65f6\u56de\u6536\u4e00\u6b21\u3002\u4f46\u662f\u5b9e\u9645\u5e94\u7528\u4e2d\uff0c\u6211\u4eec\u4e0d\u80fd\u8f83\u771f\u7684\u53ea\u7ed9\u4ed6\u4eec\u7559\u4e0b2%\uff0c\u6362\u53e5\u8bdd\u8bf4\u5f53\u5185\u5b58\u4f7f\u7528\u8fbe\u523098%\u65f6\u624dGC \u5c31\u6709\u70b9\u665a\u4e86\uff0c\u5e94\u8be5\u662f\u591a\u4e00\u4e9b\u9884\u755910%\u5185\u5b58\u7a7a\u95f4\uff0c\u8fd9\u9884\u7559\u4e0b\u6765\u7684\u7a7a\u95f4\u6211\u4eec\u79f0\u4e3aS\u533a\uff08\u6709\u4e24\u4e2as\u533a\uff1as1 \u548c\u00a0 s0\uff09\uff0cS\u533a\u662f\u7528\u6765\u5b58\u50a8\u65b0\u751f\u4ee3GC\u540e\u5b58\u6d3b\u4e0b\u6765\u7684\u5bf9\u8c61\uff0c\u800c\u6211\u4eec\u77e5\u9053\u65b0\u751f\u4ee3GC\u7b97\u6cd5\u4f7f\u7528\u7684\u662f\u590d\u5236\u56de\u6536\u7b97\u6cd5<\/strong>\u3002<\/p>\n

\u6240\u4ee5\u6211\u4eec\u5b9e\u9645GC\u53d1\u751f\u662f\u5728\uff0c\u65b0\u751f\u4ee3\u5185\u5b58\u4f7f\u7528\u8fbe\u523090%\u65f6\u5f00\u59cb\u8fdb\u884c\uff0c\u590d\u5236\u5b58\u6d3b\u7684\u5bf9\u8c61\u5230S1\u533a\uff0c\u8981\u77e5\u9053GC\u7ed3\u675f\u540e\u5728S1\u533a\u6d3b\u4e0b\u6765\u7684\u5bf9\u8c61\uff0c\u5728\u4e0b\u4e00\u6b21GC\u7684\u8303\u56f4\u662f\uff0ceden\u533a\u548cS1\uff0c\u628a\u8fd9\u4e24\u90e8\u5206\u5b58\u6d3b\u7684\u5bf9\u8c61\u653e\u5165S0\u533a\uff0c\u5982\u6b64\u53cd\u590d\uff0c\u4e0b\u4e00\u6b21GC\u8303\u56f4\u662feden\u533a\u548cS0\u533a\uff0c\u4e00\u53e5\u8bdd\u6bcf\u6b21GC\u8303\u56f4\u662feden\u533a+\u4e00\u4e2aS\u533a\u3002\uff08\u6bd4\u4f8b\u662feden:s1:s0=80%:10%:10%=8:1:1<\/code>\uff09\u8fd9\u91cc\u7684eden\u533a\uff0880%\uff09 \u548c\u5176\u4e2d\u7684\u4e00\u4e2aS\u533a\uff0810%\uff09\u00a0\u5408\u8d77\u6765\u5171\u5360\u636e90%\uff0cGC\u5c31\u662f\u6e05\u7406\u7684\u4ed6\u4eec\uff0c\u59cb\u7ec8\u4fdd\u6301\u7740\u5176\u4e2d\u4e00\u4e2aS\u533a\u662f\u7a7a\u7559\u7684\uff0c\u4fdd\u8bc1GC\u7684\u65f6\u5019\u590d\u5236\u5b58\u6d3b\u7684\u5bf9\u8c61\u6709\u4e2a\u5b58\u50a8\u7684\u5730\u65b9\u3002<\/p>\n

<\/p>\n

\u95ee\u8fd9\u6837\u505a\u7684\u597d\u5904\u662f\u4ec0\u4e48\uff1f<\/p>\n

\u7b54\uff1a\u9ad8\u6548\uff01\uff01\uff01GC \u7b97\u6cd5\u603b\u4f53\u5c31\u662f\u4e09\u79cd\uff1a1 \u590d\u5236\u00a0 2 \u6807\u8bb0\u00a0 3\u6807\u8bb0\u6574\u7406\uff0c\u5783\u573e\u56de\u6536\u7b97\u6cd5\u5c06\u8fd9\u51e0\u79cd\u9009\u62e9\u8d77\u6765\u76f8\u4e92\u7ec4\u5408\u3002\u6beb\u65e0\u7591\u95ee\uff0c\u53ea\u5b58\u5728\u5c11\u91cf\u5b58\u6d3b\u7684\u5bf9\u8c61\uff0c\u53ea\u9700\u590d\u5236\u5c11\u91cf\u5b58\u6d3b\u7684\u5bf9\u8c61\uff0c\u8fdc\u8fdc\u6bd4\u6807\u8bb0\u548c\u6807\u8bb0\u6574\u7406\u9ad8\u6548\u591a\u3002<\/p>\n

\n

\u6ce8\u610f\uff1a\u5982\u4f55\u5224\u65ad\u5bf9\u8c61\u5b58\u6d3b\u53ef\u7528\uff0c\u53ef\u8fbe\u6027\u5206\u6790\u6cd5\u6765\u5224\u65ad\uff1a\u901a\u8fc7\u4e00\u7cfb\u5217\u79f0\u4e3a GCRoot \u5bf9\u8c61\u505a\u8d77\u70b9\uff0c\u4ece\u8fd9\u4e9b\u8282\u70b9\u5411\u4e0b\u641c\u7d22\uff0c\u641c\u7d22\u6240\u8d70\u8fc7\u7684\u8def\u5f84\u79f0\u4e3a\u5f15\u7528\u94fe\uff0c\u5982\u679c\u4e00\u4e2a\u5bf9\u8c61\u5728\u5f15\u7528\u94fe\u4e0a\uff0c\u5c31\u8bf4\u662f\u53ef\u8fbe\u7684\uff0c\u8fd9\u79cd\u5bf9\u8c61\u5c31\u662f\u9700\u8981\u5b58\u6d3b\u4e0b\u6765\u7684\uff01\uff01\u4f5c\u4e3aGC Roots\u7684\u5bf9\u8c61\u5305\u62ec\u4e0b\u9762\u51e0\u79cd\uff1a<\/p>\n

    \n
  1. \u5f53\u524d\u865a\u62df\u673a\u6808\u4e2d\u5c40\u90e8\u53d8\u91cf\u8868\u4e2d\u7684\u5f15\u7528\u7684\u5bf9\u8c61<\/li>\n
  2. \u5f53\u524d\u672c\u5730\u65b9\u6cd5\u6808\u4e2d\u5c40\u90e8\u53d8\u91cf\u8868\u4e2d\u7684\u5f15\u7528\u7684\u5bf9\u8c61<\/li>\n
  3. \u65b9\u6cd5\u533a\u4e2d\u7c7b\u9759\u6001\u5c5e\u6027\u5f15\u7528\u7684\u5bf9\u8c61<\/li>\n
  4. \u65b9\u6cd5\u533a\u4e2d\u7684\u5e38\u91cf\u5f15\u7528\u7684\u5bf9\u8c61<\/li>\n<\/ol>\n<\/blockquote>\n

    \u8981\u77e5\u9053\u8bbe\u7f6eSurvivor\u533a\u662f\u4e3a\u4e86\u51cf\u5c11\u9001\u5230\u8001\u5e74\u4ee3\u7684\u5bf9\u8c61\uff01\uff01\uff01<\/p>\n

    \u5177\u4f53\u6765\u8bf4<\/p>\n

    \u9996\u5148\uff0c\u5806 = \u65b0\u751f\u4ee3 + \u8001\u5e74\u4ee3\uff0c\u5176\u4e2d\uff0c\u65b0\u751f\u4ee3\u4e3aeden+from+to<\/code>\uff0ceden:from:to=8:1:1<\/code>\u9ed8\u8ba4\u4f1a\u8fd9\u6837<\/p>\n

    \"Java\u5806\u7a7a\u95f4\u7ed3\u6784\"<\/p>\n

      \n
    • \u5806\u5927\u5c0f = \u65b0\u751f\u4ee3 + \u8001\u5e74\u4ee3\u3002\u5806\u7684\u5927\u5c0f\u53ef\u901a\u8fc7\u53c2\u6570\u2013Xms<\/code>\uff08\u5806\u7684\u521d\u59cb\u5bb9\u91cf\uff09\u3001-Xmx<\/code>\uff08\u5806\u7684\u6700\u5927\u5bb9\u91cf\uff09 \u6765\u6307\u5b9a\u3002<\/li>\n
    • \u5176\u4e2d\uff0c\u65b0\u751f\u4ee3 ( Young ) \u88ab\u7ec6\u5206\u4e3a Eden \u548c \u4e24\u4e2a Survivor \u533a\u57df\uff0c\u8fd9\u4e24\u4e2a Survivor \u533a\u57df\u5206\u522b\u88ab\u547d\u540d\u4e3a from \u548c to\uff0c\u4ee5\u793a\u533a\u5206\u3002\u9ed8\u8ba4\u7684\uff0cedem:from:to = 8:1:1<\/code>(\u53ef\u4ee5\u901a\u8fc7\u53c2\u6570\u2013XX:SurvivorRatio<\/code>\u6765\u8bbe\u5b9a\u3002<\/li>\n
    • Survivor\u533a\u548cEden\u533a\u7684\u6bd4\u503c\uff1a-XX:SurvivorRatio=8<\/code>\u8868\u793a Eden \uff1a\u4e24\u4e2aSurvivor = 8 : 2<\/code>\uff0c\u6bcf\u4e2aSurvivor\u5360 1\/10\uff1b\u53ef\u4ee5\u4fee\u6539\u4e3a-XX:SurvivorRatio=2<\/code>\uff0c2 \u8868\u793aEden \uff1a\u4e24\u4e2aSurvivor\u00a0 = 2 : 2<\/code>\uff0c\u5404\u5360\u4e00\u534a<\/li>\n
    • JVM \u6bcf\u6b21\u53ea\u4f1a\u4f7f\u7528 Eden \u548c\u5176\u4e2d\u7684\u4e00\u5757 Survivor \u533a\u57df\u6765\u4e3a\u5bf9\u8c61\u670d\u52a1\uff0c\u6240\u4ee5\u65e0\u8bba\u4ec0\u4e48\u65f6\u5019\uff0c\u603b\u662f\u6709\u4e00\u5757 Survivor \u533a\u57df\u662f\u7a7a\u95f2\u7740\u7684<\/li>\n
    • \u65b0\u751f\u4ee3\u5b9e\u9645\u53ef\u7528\u7684\u5185\u5b58\u7a7a\u95f4\u4e3a 9\/10 ( \u537390% )\u7684\u65b0\u751f\u4ee3\u7a7a\u95f4<\/li>\n<\/ul>\n

      \u5f53\u5bf9\u8c61\u5728 Eden\uff08\u5305\u62ec\u4e00\u4e2a Survivor \u533a\u57df\uff0c\u5c31\u662f\u6307\u4e24\u4e2aSurvivor \u533a\u5176\u4e2d\u4e00\u4e2a\uff0c\u8fd9\u91cc\u5047\u8bbe\u662f from \u533a\u57df\uff09\u51fa\u751f\u540e\uff0c\u5728\u7ecf\u8fc7\u4e00\u6b21 Minor GC \u524d\uff0c\u4f1a\u6807\u8bb0\u4e0d\u9700\u8981\u6e05\u9664\u7684\u5bf9\u8c61\uff0c\u7136\u540e\u4f7f\u7528\u590d\u5236\u7b97\u6cd5\u5c06\u6807\u8bb0\u7684\u5bf9\u8c61\u590d\u5236\u5230\u53e6\u5916\u4e00\u5757 Survivor\u533a\uff08\u5373Survivor\u533a\u57df\u4e2d\u7684to\u533a\u57df\uff09\u4e2d\uff0c\u7136\u540e\u6e05\u7406\u6240\u4f7f\u7528\u8fc7\u7684 Eden \u4ee5\u53ca Survivor \u533a\u57df \uff08\u5373 from \u533a\u57df\uff09\uff0c\u5e76\u4e14\u5c06\u8fd9\u4e9b\u5b58\u6d3b\u7684\u5bf9\u8c61\u7684\u5e74\u9f84\u8bbe\u7f6e\u4e3a 1\uff0c\uff08\u7136\u540e\u518d\u6b21\u540c\u4e0a\uff0c\u4ee5\u540e\u5bf9\u8c61\u5728 Survivor \u533a\u6bcf\u71ac\u8fc7\u4e00\u6b21 Minor GC\uff0c\u5c31\u5c06\u5bf9\u8c61\u7684\u5e74\u9f84+1<\/code>\uff0c\u5f53\u5bf9\u8c61\u7684\u5e74\u9f84\u8fbe\u5230\u67d0\u4e2a\u503c\u65f6\uff08\u9ed8\u8ba4\u662f 15 \u5c81\uff0cCMS\u9ed8\u8ba46\u5c81\uff0c\u53ef\u4ee5\u901a\u8fc7\u53c2\u6570-XX:MaxTenuringThreshold<\/code>\u6765\u8bbe\u5b9a\uff09\uff0c\u8fd9\u4e9b\u5bf9\u8c61\u5c31\u4f1a\u6210\u4e3a\u8001\u5e74\u4ee3<\/strong><\/p>\n

      \n

      \u8865\u5145\uff1a\u4f46\u8fd9\u4e5f\u4e0d\u662f\u7edd\u5bf9\u7684\uff0c\u5bf9\u4e8e\u4e00\u4e9b\u8f83\u5927\u7684\u5bf9\u8c61\uff08\u5373\u9700\u8981\u5206\u914d\u4e00\u5757\u8f83\u5927\u7684\u8fde\u7eed\u5185\u5b58\u7a7a\u95f4\uff09\u5219\u662f\u76f4\u63a5\u8fdb\u5165\u5230\u8001\u5e74\u4ee3<\/p>\n<\/blockquote>\n

      \u8fd8\u6709\u5f53\u4ee3\u7801\u4e2d\u8c03\u7528System.gc()<\/code>\u5bf9\u4e8e\u53ef\u8fbe\u7684\u5bf9\u8c61\u4f1a\u63d0\u524d\u8fdb\u5165\u8001\u5e74\u4ee3\uff0c\u5e76\u4e14\u8fd9\u4e2a\u65b9\u6cd5\u5148minor gc<\/code>\u7136\u540e\u5728full gc<\/code><\/p>\n","protected":false},"excerpt":{"rendered":"

      GC\u662f\u7edf\u8ba1\u5b66\u6d4b\u7b97\u51fa\u5f53\u5185\u5b58\u4f7f\u7528\u8d85\u8fc798%\u4ee5\u4e0a\u65f6\uff0c\u5185\u5b58\u5c31\u5e94\u8be5\u88abminor gc\u65f6\u56de\u6536\u4e00\u6b21\u3002\u4f46\u662f\u5b9e\u9645\u5e94\u7528\u4e2d\uff0c\u6211\u4eec\u4e0d\u80fd […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[43],"tags":[59],"class_list":["post-116","post","type-post","status-publish","format-standard","hentry","category-java-basic","tag-jvm"],"_links":{"self":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts\/116","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/comments?post=116"}],"version-history":[{"count":0,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts\/116\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/media?parent=116"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/categories?post=116"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/tags?post=116"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}