{"id":2870,"date":"2015-03-23T09:16:35","date_gmt":"2015-03-23T01:16:35","guid":{"rendered":"http:\/\/leybreeze.com\/blog\/?p=2870"},"modified":"2015-03-23T09:16:35","modified_gmt":"2015-03-23T01:16:35","slug":"java-%e7%9a%84%e5%86%85%e5%ad%98%e5%a4%a7%e5%b0%8f%e4%b8%8e%e5%9e%83%e5%9c%be%e5%9b%9e%e6%94%b6%e7%ae%80%e8%bf%b0","status":"publish","type":"post","link":"http:\/\/leybreeze.com\/blog\/?p=2870","title":{"rendered":"Java \u7684\u5185\u5b58\u5927\u5c0f\u4e0e\u5783\u573e\u56de\u6536\u7b80\u8ff0"},"content":{"rendered":"<p>\u4e00\u4e9b Java \u7a0b\u5e8f\u5728\u9ad8\u8d1f\u8377\u65f6\u6027\u80fd\u4f1a\u51fa\u73b0\u663e\u8457\u4e0b\u964d\u3002\u4e00\u4e2a\u53ef\u80fd\u7684\u539f\u56e0\u662f\u6ca1\u6709\u8bbe\u5b9a\u6070\u5f53\u7684\u5185\u5b58\u5927\u5c0f\uff08memory sizing\uff09\uff0c\u5bfc\u81f4\u5783\u573e\u56de\u6536\uff08Garbage collection\uff0c\u4e0b\u79f0 GC\uff09\u9891\u7e41\u6267\u884c\u3002\u5373\u4f7f CPU \u6ee1\u8d1f\u8377\u8fd0\u4f5c\uff0c\u6027\u80fd\u4f9d\u7136\u8f83\u5dee\u3002<\/p>\n<p>JVM \u7684\u5185\u5b58\u5206 Java \u4e13\u7528\u533a\u57df\u4e0e C Heap \u4e24\u90e8\u5206\uff0c\u5176\u4e2d\u524d\u8005\u53c8\u5206\u4e3a\u7ef4\u62a4 Java \u5bf9\u8c61\u7684 Java Heap \u533a\u57df\u4e0e\u7ef4\u62a4\u7c7b\u4fe1\u606f\u7684\u00a0Permanent \u533a\u57df\u3002\u4e00\u4e9b\u91c7\u7528\u4e86\u5206\u4ee3\u6536\u96c6\u673a\u5236\uff08Generational Garbage Collection\uff0c\u6216\u79f0 Generation Scavenging\uff09\u7684 GC \u7cfb\u7edf\u8fd8\u5c06 Java Heap \u8fdb\u4e00\u6b65\u7ec6\u5206\u4e3a\u00a0Eden\u3001Survivor\u00a0\u4e0e\u00a0Old \u533a\u57df\u3002Eden \u7ef4\u62a4\u751f\u6210\u7684\u5bf9\u8c61\uff0cGC \u65f6\u672a\u88ab\u56de\u6536\u7684\u5bf9\u8c61\u5c06\u88ab\u79fb\u5165 Survivor\uff0c\u957f\u671f\u5b58\u5728\u7684\u5bf9\u8c61\u8fdb\u4e00\u6b65\u8fdb\u5165 Old \u533a\u57df\u3002<\/p>\n<p>\u5bf9\u4e8e\u5206\u4ee3\u6536\u96c6\uff0cGC \u53ef\u5206\u4e3a Full GC \u4e0e Copy GC\uff0c\u5176\u4e2d\uff0cCopy GC \u4ec5\u9488\u5bf9 New \u533a\u57df\uff08Eden+Survivor\uff09\uff0cFull GC \u5219\u9488\u5bf9\u6240\u6709\u533a\u57df\u3002\u4e3a\u9632\u6b62 GC \u8fc7\u4e8e\u9891\u7e41\uff0c\u6211\u4eec\u9700\u8981\u8bbe\u7f6e\u5408\u9002\u7684\u5185\u5b58\u5927\u5c0f\u3002\u5e38\u89c1\u7684\u60c5\u51b5\u6709\u4ee5\u4e0b\u8fd9\u4e9b\uff1a<\/p>\n<p>Copy GC<\/p>\n<ul>\n<li>Eden \u533a\u57df\u7a7a\u95f4\u4e0d\u8db3<\/li>\n<\/ul>\n<p>Full GC<\/p>\n<ul>\n<li>Eden \u533a\u57df\u7a7a\u95f4\u4e0d\u8db3\u65f6\uff0cOld \u533a\u57df\u7684\u53ef\u7528\u5185\u5b58\u5927\u5c0f\u4e0d\u8db3\u4ee5\u5bb9\u7eb3 New \u533a\u57df\u7684\u5df2\u4f7f\u7528\u5185\u5b58<\/li>\n<li>New \u533a\u57df\u4e0e Old \u533a\u57df\u7684\u53ef\u7528\u5185\u5b58\u7a7a\u95f4\u4e0d\u8db3<\/li>\n<li>GC \u540e Old \u533a\u57df\u7684\u5269\u4f59\u7a7a\u95f4\u8fc7\u4f4e<\/li>\n<li>GC \u540e Old \u533a\u57df\u7684\u7a7a\u95f4\u589e\u52a0<\/li>\n<li>Permanent \u533a\u57df\u7684\u53ef\u7528\u7a7a\u95f4\u4e0d\u8db3<\/li>\n<\/ul>\n<p>\u5728\u7a0b\u5e8f\u6267\u884c\u8fc7\u7a0b\u4e2d\uff0cPermanent \u533a\u57df\u5f88\u5c11\u53d1\u751f\u53d8\u5316\uff0c\u56e0\u6b64\u6211\u4eec\u56e0\u4e3b\u8981\u8003\u8651 Full GC \u7684\u524d\u4e24\u79cd\u60c5\u51b5\u3002\u672a\u907f\u514d Old \u533a\u57df\u7684\u7a7a\u95f4\u589e\u52a0\uff0c\u5efa\u8bae\u5c06 Java Heap \u7684\u521d\u59cb\u503c\u4e0e\u6700\u5927\u503c\u8bbe\u4e3a\u540c\u4e00\u503c\u3002<\/p>\n<p>\u901a\u5e38\uff0cFull GC \u66f4\u4e3a\u8017\u65f6\uff0c\u56e0\u6b64\u6211\u4eec\u5e94\u4e3b\u8981\u8003\u8651\u51cf\u5c11 Full GC\uff0c\u4ee4 Copy GC \u53ef\u4ee5\u89e3\u51b3\u5927\u90e8\u5206\u56de\u6536\u3002\u4e3a\u6b64\uff0cOld \u533a\u57df\u7684\u5185\u5b58\u5927\u5c0f\u662f\u4e00\u4e2a\u5173\u952e\u3002<\/p>\n<p>Old \u533a\u57df\u7684\u5185\u5b58\u5927\u5c0f\u5e94\u4e0e Java \u7a0b\u5e8f\u5360\u7528\u5185\u5b58\u3001Java \u670d\u52a1\u5668\u5360\u7528\u5185\u5b58\uff0c\u53ca New \u533a\u57df\u7684\u5185\u5b58\u5927\u5c0f\uff0c\u4e4b\u548c\uff0c\u76f8\u5f53\u3002<\/p>\n<p>\u4e3e\u4f8b\u6765\u8bf4\uff0c\u5bf9\u4e8e Web \u7a0b\u5e8f\uff0c\u4e8b\u52a1\u5904\u7406\u5360\u7528\u7684\u5185\u5b58\u53ef\u4ee5\u88ab\u7acb\u5373\u91ca\u653e\uff0c\u4f1a\u8bdd\u5360\u7528\u7684\u5185\u5b58\u5219\u9700\u8981\u957f\u671f\u4fdd\u5b58\u3002\u56e0\u6b64\u540e\u8005\u5e94\u5f52\u4e3a Java \u7a0b\u5e8f\u5360\u7528\u5185\u5b58\u3002<\/p>\n<p>New \u533a\u57df\u7684\u5185\u5b58\u5927\u5c0f\u4e5f\u9700\u8981\u4e13\u95e8\u8003\u8651\uff0c\u5c24\u5176\u662f\u00a0Survivor \u533a\u57df\u7684\u5927\u5c0f\u5341\u5206\u91cd\u8981\u3002\u5982\u679c\u00a0Survivor \u533a\u57df\u7684\u5185\u5b58\u5927\u5c0f\u4e0d\u8db3\uff0c\u5bf9\u8c61\u5c31\u9700\u8981\u88ab\u79fb\u52a8\u81f3 Old \u533a\u57df\u3002\u5982\u679c\u8fd9\u4e9b\u5bf9\u8c61\u7684\u751f\u5b58\u5468\u671f\u4e0d\u591f\u957f\uff0c\u5c31\u4f1a\u8fdb\u4e00\u6b65\u5f15\u53d1 Full GC\u3002\u589e\u52a0 Survivor \u533a\u57df\u53ef\u4ee5\u7f13\u89e3\u8be5\u95ee\u9898\u3002\u7136\u800c\uff0c\u5982\u679c Survivor \u533a\u57df\u8fc7\u5927\uff0cCopy GC \u7684\u5904\u7406\u65f6\u95f4\u5c31\u4f1a\u589e\u52a0\u3002\u56e0\u6b64\uff0c\u5e94\u5f53\u8bbe\u7f6e\u4e00\u4e2a\u9600\u503c\uff0c\u5c06\u7ecf\u5386 Copy GC \u6b21\u6570\u8d85\u8fc7\u8be5\u503c\u7684\u5bf9\u8c61\u79fb\u690d Old \u533a\u57df\u3002\u5e94\u5c3d\u53ef\u80fd\u907f\u514d Survivor \u533a\u57df\u5df2\u6ee1\uff0c\u5bf9\u8c61\u4ece Eden \u533a\u57df\u76f4\u63a5\u88ab\u79fb\u52a8\u81f3 Ole \u533a\u57df\u7684\u60c5\u51b5\u3002\u4e3a\u6b64\uff0c\u9700\u8981\u5728 Copy GC \u53d1\u751f\u540e\u68c0\u67e5 Survivor \u533a\u57df\u662f\u5426\u88ab\u5b8c\u5168\u5360\u7528\uff0c\u4ee5\u53ca\u79fb\u52a8\u81f3 Old \u533a\u57df\u7684\u5bf9\u8c61\u5e74\u9f84\uff08\u751f\u5b58\u6b21\u6570\uff09\u662f\u5426\u5408\u9002\u3002\u5982\u6709\u53ef\u80fd\uff0c\u5e94\u4e3a Survivor \u533a\u57df\u5206\u914d\u8f83\u5927\u7684\u5185\u5b58\u5927\u5c0f\uff0c\u4ee5\u9002\u5e94\u9700\u6c42\u3002\u5177\u4f53\u7684\u5185\u5b58\u5927\u5c0f\u4f30\u7b97\u65b9\u5f0f\uff0c\u53ef\u4ee5\u67e5\u627e\u5176\u4ed6\u76f8\u5173\u6587\u7ae0\u3002<\/p>\n<p>Eden \u533a\u57df\u7684\u5185\u5b58\u5927\u5c0f\u5c06\u76f4\u63a5\u5f71\u54cd Copy GC \u7684\u9891\u7387\u3002\u901a\u5e38\uff0c\u6bcf\u53d1\u751f 10-20 \u6b21 Copy GC \u540e\u6267\u884c\u4e00\u6b21 Full GC \u8f83\u4e3a\u5408\u9002\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e00\u4e9b Java \u7a0b\u5e8f\u5728\u9ad8\u8d1f\u8377\u65f6\u6027\u80fd\u4f1a\u51fa\u73b0\u663e\u8457\u4e0b\u964d\u3002\u4e00\u4e2a\u53ef\u80fd\u7684\u539f\u56e0\u662f\u6ca1\u6709\u8bbe\u5b9a\u6070\u5f53\u7684\u5185\u5b58\u5927\u5c0f\uff08memory siz &hellip; <a href=\"http:\/\/leybreeze.com\/blog\/?p=2870\" class=\"more-link\">\u7ee7\u7eed\u9605\u8bfb<span class=\"screen-reader-text\">\u201cJava \u7684\u5185\u5b58\u5927\u5c0f\u4e0e\u5783\u573e\u56de\u6536\u7b80\u8ff0\u201d<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[135],"tags":[123],"_links":{"self":[{"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2870"}],"collection":[{"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2870"}],"version-history":[{"count":6,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2870\/revisions"}],"predecessor-version":[{"id":2876,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2870\/revisions\/2876"}],"wp:attachment":[{"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2870"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2870"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2870"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}