{"id":621,"date":"2014-11-28T14:29:34","date_gmt":"2014-11-28T06:29:34","guid":{"rendered":"http:\/\/fineyi.com\/?p=621"},"modified":"2014-11-28T14:29:34","modified_gmt":"2014-11-28T06:29:34","slug":"%e4%bf%ae%e6%94%b9tomcat%e4%b8%adjvm%e9%9d%9e%e5%a0%86%e5%86%85%e5%ad%98%e9%bb%98%e8%ae%a4%e9%85%8d%e7%bd%ae%e8%a7%a3%e5%86%b3%e5%86%85%e5%ad%98%e6%ba%a2%e5%87%ba","status":"publish","type":"post","link":"http:\/\/www.fineyi.com\/?p=621","title":{"rendered":"\u4fee\u6539tomcat\u4e2dJVM\u975e\u5806\u5185\u5b58\u9ed8\u8ba4\u914d\u7f6e\u89e3\u51b3\u5185\u5b58\u6ea2\u51fa"},"content":{"rendered":"<p>\t\t\t\t&nbsp;<\/p>\n<div><span style=\"font-family: 'Microsoft Yahei';\">\u7cfb\u7edfCentOS6.4\u4e0byum\u5b89\u88c5\u4e86tomcat6\u548cjdk1.6,\u5b89\u88c5\u914d\u7f6e\u8fc7\u7a0b\u5982\u4e0b:<\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\"><a title=\"Permalink to Linux|CentOS+Nginx+Apache+MySQL+PHP+Tomcat\u7684\u914d\u7f6e\u6559\u7a0b\uff0c\u5b8c\u7f8e\u652f\u6301PHP\u3001JAVA\" href=\"http:\/\/fineyi.com\/archives\/599.html\">Linux|CentOS+Nginx+Apache+MySQL+PHP+Tomcat\u7684\u914d\u7f6e\u6559\u7a0b\uff0c\u5b8c\u7f8e\u652f\u6301PHP\u3001JAVA<\/a><\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\">tomcat\u4e2d\u90e8\u7f72\u4e24\u4e2a\u9879\u76eeA\u3001B\uff0c\u540c\u65f6\u90e8\u7f72\u65f6\u62a5\u5185\u5b58\u6ea2\u51fa\u9519\u8bef\uff0c\u7cfb\u7edfCPU\u8d1f\u8f7d\u98d9\u5347\uff0c\u800c\u5355\u72ec\u90e8\u7f72A\u3001B \u548c \u53ea\u90e8\u7f72\u591a\u4e2aA\u6216\u8005\u53ea\u90e8\u7f72\u591a\u4e2aB\u9879\u76ee\u7cfb\u7edf\u8fd0\u884c\u6b63\u5e38\u3002<\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\">\u67e5\u770b\u65e5\u5fd7\u62a5\u9519:OutOfMemoryError\uff1a PermGen space&#8230;. \u00a0\u00a0<\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\">\u67e5\u8be2\u8d44\u6599\u5f97\u77e5\uff1a\u662f\u975e\u5806\u6ea2\u51fa\uff08\u6c38\u4e45\u4fdd\u5b58\u533a\u57df\u6ea2\u51fa\uff09<\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\">\u8fd9\u79cd\u9519\u8bef\u5e38\u89c1\u5728web\u670d\u52a1\u5668\u5bf9JSP\u8fdb\u884cpre compile\u7684\u65f6\u5019\u3002\u5982\u679c\u4f60\u7684WEB APP\u4e0b\u90fd\u7528\u4e86\u5927\u91cf\u7684\u7b2c\u4e09\u65b9jar, \u5176\u5927\u5c0f\u8d85\u8fc7\u4e86jvm\u9ed8\u8ba4\u7684\u5927\u5c0f(4M)\u90a3\u4e48\u5c31\u4f1a\u4ea7\u751f\u6b64\u9519\u8bef\u4fe1\u606f\u4e86\u3002\u5982\u679cweb app\u7528\u4e86\u5927\u91cf\u7684\u7b2c\u4e09\u65b9jar\u6216\u8005\u5e94\u7528\u6709\u592a\u591a\u7684class\u6587\u4ef6\u800c\u6070\u597dMaxPermSize\u8bbe\u7f6e\u8f83\u5c0f\uff0c\u8d85\u51fa\u4e86\u4e5f\u4f1a\u5bfc\u81f4\u8fd9\u5757\u5185\u5b58\u7684\u5360\u7528\u8fc7\u591a\u9020\u6210\u6ea2\u51fa\uff0c\u6216\u8005tomcat\u70ed\u90e8\u7f72\u65f6\u4faf\u4e0d\u4f1a\u6e05\u7406\u524d\u9762\u52a0\u8f7d\u7684\u73af\u5883\uff0c\u53ea\u4f1a\u5c06context\u66f4\u6539\u4e3a\u65b0\u90e8\u7f72\u7684\uff0c\u975e\u5806\u5b58\u7684\u5185\u5bb9\u5c31\u4f1a\u8d8a\u6765\u8d8a\u591a\u3002<\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\">\u89e3\u51b3\u529e\u6cd5\uff1a\u4fee\u6539JVM\u975e\u5806\u5185\u5b58\u9ed8\u8ba4\u5927\u5c0f<\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\">\u7f51\u4e0a\u63d0\u4f9b\u7684\u65b9\u6cd5\u662f\uff1a<\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\">\u4fee\u6539tomcat\u662fbin\u76ee\u5f55\u4e0b\u7684catalina.sh\u6587\u4ef6\u4e2d\u7684\u914d\u7f6e\uff0c\u4f46\u662fyum\u5b89\u88c5\u7684tomcat\u6b64\u6587\u4ef6\u7684\u5185\u5bb9\u4e3a\u7a7a\uff0c\u5c06\u914d\u7f6e\u9879\u00a0JAVA_OPTS=&#8221; -XX:PermSize=512M -XX:MaxPermSize=1024m&#8221; \u52a0\u8fdb\u00a0catalina.sh\u6587\u4ef6\uff0c\u91cd\u542ftomcat\uff0c\u65e0\u6548\u3002<\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\">\u641c\u7d22JAVA_OPTS\u5b57\u7b26\u4e32\u627e\u5230tomcat\u7684\u914d\u7f6e\u6587\u4ef6\u4f4d\u7f6e<\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\">find \u00a0\/etc \u00a0|xargs grep &#8220;JAVA_OPTS&#8221;<\/span><\/div>\n<div>\n<pre class=\"lang:default decode:true  \">[root@AY14070314494954704eZ\u00a0tomcat6]# find \/etc |xargs grep \"JAVA_OPTS\"\u00a0\n\/etc\/tomcat6\/tomcat6.conf:#JAVA_OPTS=\"-Xminf0.1 -Xmaxf0.3\"\u00a0\n\/etc\/tomcat6\/tomcat6.conf:# Use JAVA_OPTS to set java.library.path for libtcnative.so\u00a0\n\/etc\/tomcat6\/tomcat6.conf:#JAVA_OPTS=\"-Djava.library.path=\/usr\/lib\"\u00a0\n\/etc\/tomcat6\/tomcat6.conf:JAVA_OPTS=\"${JAVA_OPTS} -Djavax.sql.DataSource.Factory=org.apache.commons.dbcp.BasicDataSourceFactory\"\n\u5728\/etc\/tomcat6\/tomcat6.conf\u6587\u4ef6\u4e2d\u52a0\u5165\nJAVA_OPTS=\" -XX:PermSize=512M -XX:MaxPermSize=1024m\"<\/pre>\n<\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\">\u91cd\u542ftomcat \u9879\u76ee\u8fd0\u884c\u6b63\u5e38\u3002<\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\">PS\uff1a\u5177\u4f53\u8bbe\u7f6e\u5927\u5c0f\u53ef\u4ee5\u6839\u636e\u7269\u7406\u5185\u5b58\u548c\u9879\u76ee\u5b9e\u9645\u8fd0\u884c\u9700\u6c42\u8fdb\u884c\u8c03\u6574\u3002<\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\">yum\u5b89\u88c5tomcat\u7684\u9ed8\u8ba4\u8def\u5f84\uff1a\/usr\/share\/tomcat6\/<\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\">\u5176\u5b83\u76f8\u5173\u8def\u5f84\u5982\u4e0b\uff1a\uff08\u4f9b\u53c2\u8003\uff09<\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\"><img decoding=\"async\" src=\"file:\/\/\/C:\/Users\/%E6%80%A1\/AppData\/Local\/YNote\/data\/yonyea@126.com\/074a57d8e197483a9f1d1a2f437a183e\/clipboard.png\" alt=\"\" data-media-type=\"image\" data-inited=\"true\" data-attr-org-src-id=\"9F890B2CC2024FDF8C801CE3FE697F72\" data-attr-org-img-file=\"file:\/\/\/C:\/Users\/%E6%80%A1\/AppData\/Local\/YNote\/data\/yonyea@126.com\/074a57d8e197483a9f1d1a2f437a183e\/clipboard.png\" \/><a href=\"http:\/\/v3.fineyi.com\/wp-content\/uploads\/2014\/11\/clipboard.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-622\" src=\"http:\/\/v3.fineyi.com\/wp-content\/uploads\/2014\/11\/clipboard.png\" alt=\"clipboard\" width=\"627\" height=\"119\" srcset=\"http:\/\/www.fineyi.com\/wp-content\/uploads\/2014\/11\/clipboard.png 627w, http:\/\/www.fineyi.com\/wp-content\/uploads\/2014\/11\/clipboard-300x57.png 300w\" sizes=\"auto, (max-width: 627px) 100vw, 627px\" \/><\/a><\/span><\/div>\n<p><span style=\"font-family: 'Microsoft Yahei';\"><i>&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;..<\/i><\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">Tomcat\u4e2dJAVA JVM\u5185\u5b58\u6ea2\u51fa\u53ca\u5408\u7406\u914d\u7f6e<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">Tomcat\u672c\u8eab\u4e0d\u80fd\u76f4\u63a5\u5728\u8ba1\u7b97\u673a\u4e0a\u8fd0\u884c\uff0c\u9700\u8981\u4f9d\u8d56\u4e8e\u786c\u4ef6\u57fa\u7840\u4e4b\u4e0a\u7684\u64cd\u4f5c\u7cfb\u7edf\u548c\u4e00\u4e2aJava\u865a\u62df\u673a\u3002Tomcat\u7684\u5185\u5b58\u6ea2\u51fa\u672c\u8d28\u5c31\u662fJVM\u5185\u5b58\u6ea2\u51fa\uff0c\u6240\u4ee5\u5728\u672c\u6587\u5f00\u59cb\u65f6\uff0c\u5e94\u8be5\u5148\u5bf9Java JVM\u6709\u5173\u5185\u5b58\u65b9\u9762\u7684\u77e5\u8bc6\u8fdb\u884c\u8be6\u7ec6\u4ecb\u7ecd\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u4e00\u3001Java JVM\u5185\u5b58\u4ecb\u7ecd<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">JVM\u7ba1\u7406\u4e24\u79cd\u7c7b\u578b\u7684\u5185\u5b58\uff0c\u5806\u548c\u975e\u5806\u3002\u6309\u7167\u5b98\u65b9\u7684\u8bf4\u6cd5\uff1a\u201cJava \u865a\u62df\u673a\u5177\u6709\u4e00\u4e2a\u5806\uff0c\u5806\u662f\u8fd0\u884c\u65f6\u6570\u636e\u533a\u57df\uff0c\u6240\u6709\u7c7b\u5b9e\u4f8b\u548c\u6570\u7ec4\u7684\u5185\u5b58\u5747\u4ece\u6b64\u5904\u5206\u914d\u3002\u5806\u662f\u5728 Java \u865a\u62df\u673a\u542f\u52a8\u65f6\u521b\u5efa\u7684\u3002\u201d\u201c\u5728JVM\u4e2d\u5806\u4e4b\u5916\u7684\u5185\u5b58\u79f0\u4e3a\u975e\u5806\u5185\u5b58(Non-heap memory)\u201d\u3002\u7b80\u5355\u6765\u8bf4\u5806\u5c31\u662fJava\u4ee3\u7801\u53ef\u53ca\u7684\u5185\u5b58\uff0c\u662f\u7559\u7ed9\u5f00\u53d1\u4eba\u5458\u4f7f\u7528\u7684\uff1b\u975e\u5806\u5c31\u662fJVM\u7559\u7ed9\u81ea\u5df1\u7528\u7684\uff0c\u6240\u4ee5\u65b9\u6cd5\u533a\u3001JVM\u5185\u90e8\u5904\u7406\u6216\u4f18\u5316\u6240\u9700\u7684\u5185\u5b58(\u5982JIT\u7f16\u8bd1\u540e\u7684\u4ee3\u7801\u7f13\u5b58)\u3001\u6bcf\u4e2a\u7c7b\u7ed3\u6784(\u5982\u8fd0\u884c\u65f6\u5e38\u6570\u6c60\u3001\u5b57\u6bb5\u548c\u65b9\u6cd5\u6570\u636e)\u4ee5\u53ca\u65b9\u6cd5\u548c\u6784\u9020\u65b9\u6cd5\u7684\u4ee3\u7801\u90fd\u5728\u975e\u5806\u5185\u5b58\u4e2d\uff0c\u5b83\u548c\u5806\u4e0d\u540c\uff0c\u8fd0\u884c\u671f\u5185GC\u4e0d\u4f1a\u91ca\u653e\u5176\u7a7a\u95f4\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">(1). \u5806\u5185\u5b58\u5206\u914d<br \/>\nJVM\u521d\u59cb\u5206\u914d\u7684\u5185\u5b58\u7531-Xms\u6307\u5b9a\uff0c\u9ed8\u8ba4\u662f\u7269\u7406\u5185\u5b58\u76841\/64\uff1bJVM\u6700\u5927\u5206\u914d\u7684\u5185\u5b58\u7531-Xmx\u6307 \u5b9a\uff0c\u9ed8\u8ba4\u662f\u7269\u7406\u5185\u5b58\u76841\/4\u3002\u9ed8\u8ba4\u7a7a\u4f59\u5806\u5185\u5b58\u5c0f\u4e8e 40%\u65f6\uff0cJVM\u5c31\u4f1a\u589e\u5927\u5806\u76f4\u5230-Xmx\u7684\u6700\u5927\u9650\u5236\uff1b\u7a7a\u4f59\u5806\u5185\u5b58\u5927\u4e8e70%\u65f6\uff0cJVM\u4f1a\u51cf\u5c11\u5806\u76f4\u5230-Xms\u7684\u6700\u5c0f\u9650\u5236\u3002\u56e0\u6b64\u670d\u52a1\u5668\u4e00\u822c\u8bbe\u7f6e-Xms\u3001 -Xmx\u76f8\u7b49\u4ee5\u907f\u514d\u5728\u6bcf\u6b21GC \u540e\u8c03\u6574\u5806\u7684\u5927\u5c0f\u3002\u53ef\u4ee5\u5229\u7528JVM\u63d0\u4f9b\u7684-Xmn -Xms -Xmx\u7b49\u9009\u9879\u53ef\u8fdb\u884c\u5806\u5185\u5b58\u8bbe\u7f6e\uff0c\u4e00\u822c\u7684\u8981\u5c06-Xms\u548c-Xmx\u9009\u9879\u8bbe\u7f6e\u4e3a\u76f8\u540c\uff0c\u800c-Xmn\u4e3a1\/4\u7684-Xmx\u503c\uff0c\u5efa\u8bae\u5806\u7684\u6700\u5927\u503c\u8bbe\u7f6e\u4e3a\u53ef\u7528\u5185\u5b58\u7684\u6700\u5927\u503c\u768480%\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u521d\u59cb\u5316\u5806\u7684\u5927\u5c0f\u662fJVM\u5728\u542f\u52a8\u65f6\u5411\u7cfb\u7edf\u7533\u8bf7\u7684\u5185\u5b58\u7684\u5927\u5c0f\u3002\u4e00\u822c\u800c\u8a00\uff0c\u8fd9\u4e2a\u53c2\u6570\u4e0d\u91cd\u8981\u3002\u4f46\u662f\u6709\u7684\u5e94\u7528\u7a0b\u5e8f\u5728\u5927\u8d1f\u8f7d\u7684\u60c5\u51b5\u4e0b\u4f1a\u6025\u5267\u5730\u5360\u7528\u66f4\u591a\u7684\u5185\u5b58\uff0c\u6b64\u65f6\u8fd9\u4e2a\u53c2\u6570\u5c31\u662f\u663e\u5f97\u975e\u5e38\u91cd\u8981\uff0c\u5982\u679cJVM\u542f\u52a8\u65f6\u8bbe\u7f6e\u4f7f\u7528\u7684\u5185\u5b58\u6bd4\u8f83\u5c0f\u800c\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\u6709\u8bb8\u591a\u5bf9\u8c61\u8fdb\u884c\u521d\u59cb\u5316\uff0cJVM\u5c31\u5fc5\u987b\u91cd\u590d\u5730\u589e\u52a0\u5185\u5b58\u6765\u6ee1\u8db3\u4f7f\u7528\u3002\u7531\u4e8e\u8fd9\u79cd\u539f\u56e0\uff0c\u6211\u4eec\u4e00\u822c\u628a-Xms\u548c-Xmx\u8bbe\u4e3a\u4e00\u6837\u5927\uff0c\u800c\u5806\u7684\u6700\u5927\u503c\u53d7\u9650\u4e8e\u7cfb\u7edf\u4f7f\u7528\u7684\u7269\u7406\u5185\u5b58\u3002\u4e00\u822c\u4f7f\u7528\u6570\u636e\u91cf\u8f83\u5927\u7684\u5e94\u7528\u7a0b\u5e8f\u4f1a\u4f7f\u7528\u6301\u4e45\u5bf9\u8c61\uff0c\u5185\u5b58\u4f7f\u7528\u6709\u53ef\u80fd\u8fc5\u901f\u5730\u589e\u957f\u3002\u5f53\u5e94\u7528\u7a0b\u5e8f\u9700\u8981\u7684\u5185\u5b58\u8d85\u51fa\u5806\u7684\u6700\u5927\u503c\u65f6JVM\u5c31\u4f1a\u63d0\u793a\u5185\u5b58\u6ea2\u51fa\uff0c\u5e76\u4e14\u5bfc\u81f4\u5e94\u7528\u670d\u52a1\u5d29\u6e83\u3002\u6240\u4ee5\uff0c\u5982\u679cXms\u8d85\u8fc7\u4e86Xmx\u503c\uff0c\u6216\u8005\u5806\u6700\u5927\u503c\u548c\u975e\u5806\u6700\u5927\u503c\u7684\u603b\u548c\u8d85\u8fc7\u4e86\u7269\u7406\u5185\u5b58\u6216\u8005\u64cd\u4f5c\u7cfb\u7edf\u7684\u6700\u5927\u9650\u5236\u90fd\u4f1a\u5f15\u8d77\u670d\u52a1\u5668\u542f\u52a8\u4e0d\u8d77\u6765\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">(2). \u975e\u5806\u5185\u5b58\u5206\u914d<br \/>\n\u4e5f\u53eb\u6c38\u4e45\u4fdd\u5b58\u7684\u533a\u57df\uff0c\u7528\u4e8e\u5b58\u653eClass\u548cMeta\u4fe1\u606f,Class\u5728\u88abLoad\u7684\u65f6\u5019\u88ab\u653e\u5165\u8be5\u533a\u57df\u3002\u5b83\u548c\u5b58\u653e\u7c7b\u5b9e\u4f8b(Instance)\u7684Heap\u533a\u57df\u4e0d\u540c,GC(Garbage Collection)\u4e0d\u4f1a\u5728\u4e3b\u7a0b\u5e8f\u8fd0\u884c\u671f\u5bf9PermGen space\u8fdb\u884c\u6e05\u7406\u3002JVM\u4f7f\u7528-XX:PermSize\u8bbe\u7f6e\u975e\u5806\u5185\u5b58\u521d\u59cb\u503c\uff0c\u9ed8\u8ba4\u662f\u7269\u7406\u5185\u5b58\u76841\/64\uff1b\u7531XX:MaxPermSize\u8bbe\u7f6e\u6700\u5927\u975e\u5806\u5185\u5b58\u7684\u5927\u5c0f\uff0c\u9ed8\u8ba4\u662f\u7269\u7406\u5185\u5b58\u76841\/4\u3002 GC\u4e0d\u4f1a\u5bf9PermGen space\u8fdb\u884c\u6e05\u7406\uff0c\u6240\u4ee5\u5982\u679c\u4f60\u7684APP\u4f1aLOAD\u5f88\u591aCLASS\u7684\u8bdd,\u5c31\u5f88\u53ef\u80fd\u51fa\u73b0PermGen space\u9519\u8bef\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">(3). JVM\u5185\u5b58\u9650\u5236(\u6700\u5927\u503c)<br \/>\n\u9996\u5148JVM\u5185\u5b58\u9650\u5236\u4e8e\u5b9e\u9645\u7684\u6700\u5927\u7269\u7406\u5185\u5b58\uff08\u5e9f\u8bdd\uff01\uff0c\u5475\u5475\uff09\uff0c\u5047\u8bbe\u7269\u7406\u5185\u5b58\u65e0\u9650\u5927\u7684\u8bdd\uff0cJVM\u5185\u5b58\u7684\u6700\u5927\u503c\u8ddf\u64cd\u4f5c\u7cfb\u7edf\u6709\u5f88\u5927\u7684\u5173\u7cfb\u3002\u7b80\u5355\u7684\u8bf4\u5c3132\u4f4d\u5904\u7406\u5668\u867d\u7136\u53ef\u63a7\u5185\u5b58\u7a7a\u95f4\u67094GB,\u4f46\u662f\u5177\u4f53\u7684\u64cd\u4f5c\u7cfb\u7edf\u4f1a\u7ed9\u4e00\u4e2a\u9650\u5236\uff0c\u8fd9\u4e2a\u9650\u5236\u4e00\u822c\u662f2GB-3GB\uff08\u4e00\u822c\u6765\u8bf4Windows\u7cfb\u7edf\u4e0b\u4e3a1.5G-2G\uff0cLinux\u7cfb\u7edf \u4e0b\u4e3a2G-3G\uff09\uff0c\u800c64bit\u4ee5\u4e0a\u7684\u5904\u7406\u5668\u5c31\u4e0d\u4f1a\u6709\u9650\u5236\u4e86\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u4e8c\u3001\u4e09\u79cd\u5185\u5b58\u6ea2\u51fa\u5f02\u5e38\u4ecb\u7ecd<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">1. OutOfMemoryError\uff1a Java heap space\u00a0 \u5806\u6ea2\u51fa<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u5185\u5b58\u6ea2\u51fa\u4e3b\u8981\u5b58\u5728\u95ee\u9898\u5c31\u662f\u51fa\u73b0\u5728\u8fd9\u4e2a\u60c5\u51b5\u4e2d\u3002\u5f53\u5728JVM\u4e2d\u5982\u679c98\uff05\u7684\u65f6\u95f4\u662f\u7528\u4e8eGC\u4e14\u53ef\u7528\u7684 Heap size \u4e0d\u8db32\uff05\u7684\u65f6\u5019\u5c06\u629b\u51fa\u6b64\u5f02\u5e38\u4fe1\u606f\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u00a02. OutOfMemoryError\uff1a PermGen space\u00a0\u00a0 \u975e\u5806\u6ea2\u51fa\uff08\u6c38\u4e45\u4fdd\u5b58\u533a\u57df\u6ea2\u51fa\uff09<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u8fd9\u79cd\u9519\u8bef\u5e38\u89c1\u5728web\u670d\u52a1\u5668\u5bf9JSP\u8fdb\u884cpre compile\u7684\u65f6\u5019\u3002\u5982\u679c\u4f60\u7684WEB APP\u4e0b\u90fd\u7528\u4e86\u5927\u91cf\u7684\u7b2c\u4e09\u65b9jar, \u5176\u5927\u5c0f\u8d85\u8fc7\u4e86jvm\u9ed8\u8ba4\u7684\u5927\u5c0f(4M)\u90a3\u4e48\u5c31\u4f1a\u4ea7\u751f\u6b64\u9519\u8bef\u4fe1\u606f\u4e86\u3002\u5982\u679cweb app\u7528\u4e86\u5927\u91cf\u7684\u7b2c\u4e09\u65b9jar\u6216\u8005\u5e94\u7528\u6709\u592a\u591a\u7684class\u6587\u4ef6\u800c\u6070\u597dMaxPermSize\u8bbe\u7f6e\u8f83\u5c0f\uff0c\u8d85\u51fa\u4e86\u4e5f\u4f1a\u5bfc\u81f4\u8fd9\u5757\u5185\u5b58\u7684\u5360\u7528\u8fc7\u591a\u9020\u6210\u6ea2\u51fa\uff0c\u6216\u8005tomcat\u70ed\u90e8\u7f72\u65f6\u4faf\u4e0d\u4f1a\u6e05\u7406\u524d\u9762\u52a0\u8f7d\u7684\u73af\u5883\uff0c\u53ea\u4f1a\u5c06context\u66f4\u6539\u4e3a\u65b0\u90e8\u7f72\u7684\uff0c\u975e\u5806\u5b58\u7684\u5185\u5bb9\u5c31\u4f1a\u8d8a\u6765\u8d8a\u591a\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">3. OutOfMemoryError\uff1a unable to create new native thread.\u00a0\u00a0 \u65e0\u6cd5\u521b\u5efa\u65b0\u7684\u7ebf\u7a0b<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u8fd9\u79cd\u73b0\u8c61\u6bd4\u8f83\u5c11\u89c1\uff0c\u4e5f\u6bd4\u8f83\u5947\u602a\uff0c\u4e3b\u8981\u662f\u548cjvm\u4e0e\u7cfb\u7edf\u5185\u5b58\u7684\u6bd4\u4f8b\u6709\u5173\u3002\u8fd9\u79cd\u602a\u4e8b\u662f\u56e0\u4e3aJVM\u5df2\u7ecf\u88ab\u7cfb\u7edf\u5206\u914d\u4e86\u5927\u91cf\u7684\u5185\u5b58\uff08\u6bd4\u59821.5G\uff09\uff0c\u5e76\u4e14\u5b83\u81f3\u5c11\u8981\u5360\u7528\u53ef\u7528\u5185\u5b58\u7684\u4e00\u534a\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u4e09\u3001Java JVM\u5185\u5b58\u914d\u7f6e<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">1. JVM\u5185\u5b58\u5206\u914d\u8bbe\u7f6e\u7684\u53c2\u6570\u6709\u56db\u4e2a<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">-Xmx\u00a0\u00a0\u00a0 Java Heap\u6700\u5927\u503c\uff0c\u9ed8\u8ba4\u503c\u4e3a\u7269\u7406\u5185\u5b58\u76841\/4\uff1b<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">-Xms\u00a0\u00a0\u00a0 Java Heap\u521d\u59cb\u503c\uff0cServer\u7aefJVM\u6700\u597d\u5c06-Xms\u548c-Xmx\u8bbe\u4e3a\u76f8\u540c\u503c\uff0c\u5f00\u53d1\u6d4b\u8bd5\u673aJVM\u53ef\u4ee5\u4fdd\u7559\u9ed8\u8ba4\u503c\uff1b<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">-Xmn\u00a0\u00a0\u00a0 Java Heap Young\u533a\u5927\u5c0f\uff0c\u4e0d\u719f\u6089\u6700\u597d\u4fdd\u7559\u9ed8\u8ba4\u503c\uff1b<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">-Xss\u00a0\u00a0\u00a0\u00a0\u00a0 \u6bcf\u4e2a\u7ebf\u7a0b\u7684Stack\u5927\u5c0f\uff0c\u4e0d\u719f\u6089\u6700\u597d\u4fdd\u7559\u9ed8\u8ba4\u503c\uff1b<\/span><\/p>\n<p><em><span style=\"font-family: 'Microsoft Yahei';\">-XX:PermSize\uff1a\u8bbe\u5b9a\u5185\u5b58\u7684\u6c38\u4e45\u4fdd\u5b58\u533a\u57df\uff1b<br \/>\n<\/span><\/em><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">-XX:MaxPermSize\uff1a\u8bbe\u5b9a\u6700\u5927\u5185\u5b58\u7684\u6c38\u4e45\u4fdd\u5b58\u533a\u57df\uff1b<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">-XX:PermSize\uff1a\u8bbe\u5b9a\u5185\u5b58\u7684\u6c38\u4e45\u4fdd\u5b58\u533a\u57df\uff1b<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">-XX:NewSize\uff1a\u8bbe\u7f6eJVM\u5806\u7684\u2018\u65b0\u751f\u4ee3\u2019\u7684\u9ed8\u8ba4\u5927\u5c0f\uff1b<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">-XX:MaxNewSize\uff1a\u8bbe\u7f6eJVM\u5806\u7684\u2018\u65b0\u751f\u4ee3\u2019\u7684\u6700\u5927\u5927\u5c0f\uff1b<br \/>\n<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">2. \u5982\u4f55\u8bbe\u7f6eJVM\u7684\u5185\u5b58\u5206\u914d<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\uff081\uff09\u5f53\u5728\u547d\u4ee4\u63d0\u793a\u7b26\u4e0b\u542f\u52a8\u5e76\u4f7f\u7528JVM\u65f6\uff08\u53ea\u5bf9\u5f53\u524d\u8fd0\u884c\u7684\u7c7bTest\u751f\u6548\uff09\uff1a<\/span><\/p>\n<div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">java -Xmx128m -Xms64m -Xmn32m -Xss16m Test<\/span><\/p>\n<\/div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\uff082\uff09\u5f53\u5728\u96c6\u6210\u5f00\u53d1\u73af\u5883\u4e0b\uff08\u5982eclipse\uff09\u542f\u52a8\u5e76\u4f7f\u7528JVM\u65f6\uff1a<\/span><\/p>\n<div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">a. \u5728eclipse\u6839\u76ee\u5f55\u4e0b\u6253\u5f00eclipse.ini\uff0c\u9ed8\u8ba4\u5185\u5bb9\u4e3a\uff08\u8fd9\u91cc\u8bbe\u7f6e\u7684\u662f\u8fd0\u884c\u5f53\u524d\u5f00\u53d1\u5de5\u5177\u7684JVM\u5185\u5b58\u5206\u914d\uff09\uff1a\u00a0 -vmargs -Xms40m -Xmx256m -vmargs\u8868\u793a\u4ee5\u4e0b\u4e3a\u865a\u62df\u673a\u8bbe\u7f6e\u53c2\u6570\uff0c\u53ef\u4fee\u6539\u5176\u4e2d\u7684\u53c2\u6570\u503c\uff0c\u4e5f\u53ef\u6dfb\u52a0-Xmn\uff0c-Xss\uff0c\u53e6\u5916\uff0ceclipse.ini\u5185\u8fd8\u53ef\u4ee5\u8bbe\u7f6e\u975e\u00a0\u00a0 \u5806\u5185\u5b58\uff0c\u5982\uff1a-XX:PermSize=56m\uff0c-XX:MaxPermSize=128m\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">b. \u6253\u5f00eclipse\uff0d\u7a97\u53e3\uff0d\u9996\u9009\u9879\uff0dJava\uff0d\u5df2\u5b89\u88c5\u7684JRE\uff08\u5bf9\u5728\u5f53\u524d\u5f00\u53d1\u73af\u5883\u4e2d\u8fd0\u884c\u7684java\u7a0b\u5e8f\u7686\u751f\u6548\uff09\u00a0 \u7f16\u8f91\u5f53\u524d\u4f7f\u7528\u7684JRE\uff0c\u5728\u7f3a\u7701VM\u53c2\u6570\u4e2d\u8f93\u5165\uff1a-Xmx128m -Xms64m -Xmn32m \u2013Xss16m\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">c. \u6253\u5f00eclipse\uff0d\u8fd0\u884c\uff0d\u8fd0\u884c\uff0dJava\u5e94\u7528\u7a0b\u5e8f\uff08\u53ea\u5bf9\u6240\u8bbe\u7f6e\u7684java\u7c7b\u751f\u6548\uff09\u00a0 \u9009\u5b9a\u9700\u8bbe\u7f6e\u5185\u5b58\u5206\u914d\u7684\u7c7b\uff0d\u81ea\u53d8\u91cf\uff0c\u5728VM\u81ea\u53d8\u91cf\u4e2d\u8f93\u5165\uff1a-Xmx128m -Xms64m -Xmn32m -Xss16m\u00a0 \u6ce8\uff1a\u5982\u679c\u5728\u540c\u4e00\u5f00\u53d1\u73af\u5883\u4e2d\u540c\u65f6\u8fdb\u884c\u4e86b\u548cc\u8bbe\u7f6e\uff0c\u5219b\u8bbe\u7f6e\u751f\u6548\uff0cc\u8bbe\u7f6e\u65e0\u6548\uff0c\u5982\uff1a\u00a0 \u5f00\u53d1\u73af\u5883\u7684\u8bbe\u7f6e\u4e3a\uff1a-Xmx256m\uff0c\u800c\u7c7bTest\u7684\u8bbe\u7f6e\u4e3a\uff1a-Xmx128m -Xms64m\uff0c\u5219\u8fd0\u884cTest\u65f6\u751f\u6548\u7684\u8bbe\u7f6e\u4e3a\uff1a\u00a0 -Xmx256m -Xms64m\u3002<\/span><\/p>\n<\/div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\uff083\uff09\u5f53\u5728\u670d\u52a1\u5668\u73af\u5883\u4e0b\uff08\u5982Tomcat\uff09\u542f\u52a8\u5e76\u4f7f\u7528JVM\u65f6\uff08\u5bf9\u5f53\u524d\u670d\u52a1\u5668\u73af\u5883\u4e0b\u6240\u4ee5Java\u7a0b\u5e8f\u751f\u6548\uff09\uff1a<\/span><\/p>\n<div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">a. \u8bbe\u7f6e\u73af\u5883\u53d8\u91cf\uff1a\u00a0 \u53d8\u91cf\u540d\uff1aCATALINA_OPTS\u00a0 \u53d8\u91cf\u503c\uff1a-Xmx128m -Xms64m -Xmn32m -Xss16m\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">b. \u6253\u5f00Tomcat\u6839\u76ee\u5f55\u4e0b\u7684bin\u6587\u4ef6\u5939\uff0c\u7f16\u8f91catalina.bat\uff0c\u5c06\u5176\u4e2d\u7684%CATALINA_OPTS%\uff08\u5171\u6709\u56db\u5904\uff09\u66ff\u6362\u4e3a\uff1a-Xmx128m -Xms64m -Xmn32m -Xss16m\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">c. \u82e5\u6ca1\u6709catalina.bat\uff0c\u53ea\u6709tomcat.exe,tomcat6w.exe;\u5219\u53ef\u4ee5\u5728\u542f\u52a8tomcat6w.exe \u540e \u53f3\u952e\u914d\u7f6e&#8211;Java&#8211;java option \u4e0b\u9762\u8f93\u5165\uff1a<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">-Xmx256m \u2013Xms64m<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u4e5f\u53ef\u4ee5\u627e\u5230\u6ce8\u518c\u8868HKEY_LOCAL_MACHINE\\SOFTWARE\\Apache Software Foundation\\TomcatService Manager\\Tomcat6\\Parameters\\JavaOptions\u539f\u503c\u4e3a -Dcatalina.home=&#8221;C:\\ApacheGroup\\Tomcat 6.0&#8243; -Djava.endorsed.dirs=&#8221;C:\\ApacheGroup\\Tomcat 6.0\\common\\endorsed&#8221; -Xrs \u52a0\u5165\u00a0 -Xms300m\u00a0 -Xmx350m\u00a0 \uff08\u6211\u7684\u662f\u52a0\u5165-Xmx350m\uff0ctomcat\u624d\u80fd\u542f\u52a8\uff0c\u52a0\u5165-Xms300m\u00a0 -Xmx350m\u53cd\u800ctomcat\u90fd\u4e0d\u80fd\u542f\u52a8\uff09\u91cd\u8d77tomcat\u670d\u52a1,\u8bbe\u7f6e\u751f\u6548\u3002<\/span><\/p>\n<\/div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">3. \u67e5\u770bJVM\u5185\u5b58\u4fe1\u606f<\/span><\/p>\n<div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">Runtime.getRuntime().maxMemory(); \/\/\u6700\u5927\u53ef\u7528\u5185\u5b58\uff0c\u5bf9\u5e94-Xmx\u00a0<\/span><\/p>\n<\/div>\n<div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">Runtime.getRuntime().freeMemory(); \/\/\u5f53\u524dJVM\u7a7a\u95f2\u5185\u5b58\u00a0<\/span><\/p>\n<\/div>\n<div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">Runtime.getRuntime().totalMemory(); \/\/\u5f53\u524dJVM\u5360\u7528\u7684\u5185\u5b58\u603b\u6570\uff0c\u5176\u503c\u76f8\u5f53\u4e8e\u5f53\u524dJVM\u5df2\u4f7f\u7528\u7684\u5185\u5b58\u53cafreeMemory()\u7684\u603b\u548c\u00a0<\/span><\/p>\n<\/div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u5173\u4e8emaxMemory()\uff0cfreeMemory()\u548ctotalMemory()\uff1amaxMemory()\u4e3aJVM\u7684\u6700\u5927\u53ef\u7528\u5185\u5b58\uff0c\u53ef\u901a\u8fc7-Xmx\u8bbe\u7f6e\uff0c\u9ed8\u8ba4\u503c\u4e3a\u7269\u7406\u5185\u5b58\u76841\/4\uff0c\u8bbe\u7f6e\u4e0d\u80fd\u9ad8\u4e8e\u8ba1\u7b97\u673a\u7269\u7406\u5185\u5b58\uff1b\u00a0 totalMemory()\u4e3a\u5f53\u524dJVM\u5360\u7528\u7684\u5185\u5b58\u603b\u6570\uff0c\u5176\u503c\u76f8\u5f53\u4e8e\u5f53\u524dJVM\u5df2\u4f7f\u7528\u7684\u5185\u5b58\u53cafreeMemory()\u7684\u603b\u548c\uff0c\u4f1a\u968f\u7740JVM\u4f7f\u7528\u5185\u5b58\u7684\u589e\u52a0\u800c\u589e\u52a0\uff1b\u00a0 freeMemory()\u4e3a\u5f53\u524dJVM\u7a7a\u95f2\u5185\u5b58\uff0c\u56e0\u4e3aJVM\u53ea\u6709\u5728\u9700\u8981\u5185\u5b58\u65f6\u624d\u5360\u7528\u7269\u7406\u5185\u5b58\u4f7f\u7528\uff0c\u6240\u4ee5freeMemory()\u7684\u503c\u4e00\u822c\u60c5\u51b5\u4e0b\u90fd\u5f88\u5c0f\uff0c\u800cJVM\u5b9e\u9645\u53ef\u7528\u5185\u5b58\u5e76\u4e0d\u7b49\u4e8efreeMemory()\uff0c\u800c\u5e94\u8be5\u7b49\u4e8emaxMemory()-totalMemory()+freeMemory()\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">4. \u5b9e\u4f8b\uff0c\u4ee5\u4e0b\u7ed9\u51fa1G\u5185\u5b58\u73af\u5883\u4e0bjava jvm \u7684\u53c2\u6570\u8bbe\u7f6e\u53c2\u8003<\/span><\/p>\n<div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">JAVA_OPTS=&#8221;-server -Xms800m -Xmx800m -XX:PermSize=64M -XX:MaxNewSize=256m -XX:MaxPermSize=128m -Djava.awt.headless=true &#8220;<\/span><\/p>\n<\/div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u5927\u578b\u7684web\u5de5\u7a0b\uff0c\u7528tomcat\u9ed8\u8ba4\u5206\u914d\u7684\u5185\u5b58\u7a7a\u95f4\u65e0\u6cd5\u542f\u52a8\uff0c\u5982\u679c\u4e0d\u662f\u5728myeclipse\u4e2d\u542f\u52a8tomcat\u53ef\u4ee5\u5bf9tomcat\u8fd9\u6837\u8bbe\u7f6e\uff1a<\/span><\/p>\n<div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">TOMCAT_HOME\\bin\\catalina.bat \u4e2d\u6dfb\u52a0\u8fd9\u6837\u4e00\u53e5\u8bdd\uff1a<\/span><\/p>\n<\/div>\n<div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">set JAVA_OPTS= -Xmx1024M -Xms512M -XX:MaxPermSize=256m<\/span><\/p>\n<\/div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u5982\u679c\u8981\u5728myeclipse\u4e2d\u542f\u52a8\uff0c\u4e0a\u8ff0\u7684\u4fee\u6539\u5c31\u4e0d\u8d77\u4f5c\u7528\u4e86\uff0c\u53ef\u5982\u4e0b\u8bbe\u7f6e\uff1a<\/span><\/p>\n<div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">Myeclipse-&gt;preferences-&gt;myeclipse-&gt;servers-&gt;tomcat-&gt;tomcat\u00d7.\u00d7-&gt;JDK\u9762\u677f\u4e2d\u7684<\/span><\/p>\n<\/div>\n<div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">Optional Java VM arguments\u4e2d\u6dfb\u52a0\uff1a-Xmx1024M -Xms512M -XX:MaxPermSize=256m<\/span><\/p>\n<\/div>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u5bf9\u4e8e\u5355\u72ec\u7684.class\uff0c\u53ef\u4ee5\u7528\u4e0b\u9762\u7684\u65b9\u6cd5\u5bf9Test\u8fd0\u884c\u65f6\u7684jvm\u5185\u5b58\u8fdb\u884c\u8bbe\u7f6e\u3002 java -Xms64m -Xmx256m Test -Xms\u662f\u8bbe\u7f6e\u5185\u5b58\u521d\u59cb\u5316\u7684\u5927\u5c0f -Xmx\u662f\u8bbe\u7f6e\u6700\u5927\u80fd\u591f\u4f7f\u7528\u5185\u5b58\u7684\u5927\u5c0f\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u56db\u3001JVM\u5185\u5b58\u914d\u7f6e\u4e0eGC<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u9700\u8981\u8003\u8651\u7684\u662fJava\u63d0\u4f9b\u7684\u5783\u573e\u56de\u6536\u673a\u5236\u3002JVM\u7684\u5806\u5927\u5c0f\u51b3\u5b9a\u4e86JVM\u82b1\u8d39\u5728\u6536\u96c6\u5783\u573e\u4e0a\u7684\u65f6\u95f4\u548c\u9891\u5ea6\u3002\u6536\u96c6\u5783\u573e\u53ef\u4ee5\u63a5\u53d7\u7684\u901f\u5ea6\u4e0e\u5e94\u7528\u6709\u5173\uff0c\u5e94\u8be5\u901a\u8fc7\u5206\u6790\u5b9e\u9645\u7684\u5783\u573e\u6536\u96c6\u7684\u65f6\u95f4\u548c\u9891\u7387\u6765\u8c03\u6574\u3002\u5982\u679c\u5806\u7684\u5927\u5c0f\u5f88\u5927\uff0c\u90a3\u4e48\u5b8c\u5168\u5783\u573e\u6536\u96c6\u5c31\u4f1a\u5f88\u6162\uff0c\u4f46\u662f\u9891\u5ea6\u4f1a\u964d\u4f4e\u3002\u5982\u679c\u4f60\u628a\u5806\u7684\u5927\u5c0f\u548c\u5185\u5b58\u7684\u9700\u8981\u4e00\u81f4\uff0c\u5b8c\u5168\u6536\u96c6\u5c31\u5f88\u5feb\uff0c\u4f46\u662f\u4f1a\u66f4\u52a0\u9891\u7e41\u3002\u8c03\u6574\u5806\u5927\u5c0f\u7684\u7684\u76ee\u7684\u662f\u6700\u5c0f\u5316\u5783\u573e\u6536\u96c6\u7684\u65f6\u95f4\uff0c\u4ee5\u5728\u7279\u5b9a\u7684\u65f6\u95f4\u5185\u6700\u5927\u5316\u5904\u7406\u5ba2\u6237\u7684\u8bf7\u6c42\u3002\u5728\u57fa\u51c6\u6d4b\u8bd5\u7684\u65f6\u5019\uff0c\u4e3a\u4fdd\u8bc1\u6700\u597d\u7684\u6027\u80fd\uff0c\u8981\u628a\u5806\u7684\u5927\u5c0f\u8bbe\u5927\uff0c\u4fdd\u8bc1\u5783\u573e\u6536\u96c6\u4e0d\u5728\u6574\u4e2a\u57fa\u51c6\u6d4b\u8bd5\u7684\u8fc7\u7a0b\u4e2d\u51fa\u73b0\u3002\u5982\u679c\u7cfb\u7edf\u82b1\u8d39\u5f88\u591a\u7684\u65f6\u95f4\u6536\u96c6\u5783\u573e\uff0c\u8bf7\u51cf\u5c0f\u5806\u5927\u5c0f\u3002\u4e00\u6b21\u5b8c\u5168\u7684\u5783\u573e\u6536\u96c6\u5e94\u8be5\u4e0d\u8d85\u8fc7 3-5 \u79d2\u3002\u5982\u679c\u5783\u573e\u6536\u96c6\u6210\u4e3a\u74f6\u9888\uff0c\u90a3\u4e48\u9700\u8981\u6307\u5b9a\u5806\u7684\u5927\u5c0f\uff0c\u68c0\u67e5\u5783\u573e\u6536\u96c6\u7684\u8be6\u7ec6\u8f93\u51fa\uff0c\u7814\u7a76\u5783\u573e\u6536\u96c6\u53c2\u6570\u5bf9\u6027\u80fd\u7684\u5f71\u54cd\u3002\u4e00\u822c\u8bf4\u6765\uff0c\u4f60\u5e94\u8be5\u4f7f\u7528\u7269\u7406\u5185\u5b58\u7684 80% \u4f5c\u4e3a\u5806\u5927\u5c0f\u3002\u5f53\u589e\u52a0\u5904\u7406\u5668\u65f6\uff0c\u8bb0\u5f97\u589e\u52a0\u5185\u5b58\uff0c\u56e0\u4e3a\u5206\u914d\u53ef\u4ee5\u5e76\u884c\u8fdb\u884c\uff0c\u800c\u5783\u573e\u6536\u96c6\u4e0d\u662f\u5e76\u884c\u7684\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">Java Heap\u5206\u4e3a3\u4e2a\u533a\uff1a<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">1.Young 2.Old 3.Permanent\u3002Young\u4fdd\u5b58\u521a\u5b9e\u4f8b\u5316\u7684\u5bf9\u8c61\u3002\u5f53\u8be5\u533a\u88ab\u586b\u6ee1\u65f6\uff0cGC\u4f1a\u5c06\u5bf9\u8c61\u79fb\u5230Old\u533a\u3002Permanent\u533a\u5219\u8d1f\u8d23\u4fdd\u5b58\u53cd\u5c04\u5bf9\u8c61\uff0c\u672c\u6587\u4e0d\u8ba8\u8bba\u8be5\u533a\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">JVM\u67092\u4e2aGC\u7ebf\u7a0b\uff1a<br \/>\n\u7b2c\u4e00\u4e2a\u7ebf\u7a0b\u8d1f\u8d23\u56de\u6536Heap\u7684Young\u533a\uff1b<br \/>\n\u7b2c\u4e8c\u4e2a\u7ebf\u7a0b\u5728Heap\u4e0d\u8db3\u65f6\uff0c\u904d\u5386Heap\uff0c\u5c06Young \u533a\u5347\u7ea7\u4e3aOlder\u533a\uff0cOlder\u533a\u7684\u5927\u5c0f\u7b49\u4e8e-Xmx\u51cf\u53bb-Xmn\uff0c\u4e0d\u80fd\u5c06-Xms\u7684\u503c\u8bbe\u7684\u8fc7\u5927\uff0c\u56e0\u4e3a\u7b2c\u4e8c\u4e2a\u7ebf\u7a0b\u88ab\u8feb\u8fd0\u884c\u4f1a\u964d\u4f4eJVM\u7684\u6027\u80fd\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u4e3a\u4ec0\u4e48\u4e00\u4e9b\u7a0b\u5e8f\u9891\u7e41\u53d1\u751fGC\uff1f\u6709\u5982\u4e0b\u539f\u56e0\uff1a<br \/>\n1. \u7a0b\u5e8f\u5185\u8c03\u7528\u4e86System.gc()\u6216Runtime.gc()\u3002<br \/>\n2. \u4e00\u4e9b\u4e2d\u95f4\u4ef6\u8f6f\u4ef6\u8c03\u7528\u81ea\u5df1\u7684GC\u65b9\u6cd5\uff0c\u6b64\u65f6\u9700\u8981\u8bbe\u7f6e\u53c2\u6570\u7981\u6b62\u8fd9\u4e9bGC\u3002<br \/>\n3. Java\u7684Heap\u592a\u5c0f\uff0c\u4e00\u822c\u9ed8\u8ba4\u7684Heap\u503c\u90fd\u5f88\u5c0f\u3002<br \/>\n4. \u9891\u7e41\u5b9e\u4f8b\u5316\u5bf9\u8c61\uff0cRelease\u5bf9\u8c61 \u6b64\u65f6\u5c3d\u91cf\u4fdd\u5b58\u5e76\u91cd\u7528\u5bf9\u8c61\uff0c\u4f8b\u5982\u4f7f\u7528StringBuffer()\u548cString()\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u5982\u679c\u4f60\u53d1\u73b0\u6bcf\u6b21GC\u540e\uff0cHeap\u7684\u5269\u4f59\u7a7a\u95f4\u4f1a\u662f\u603b\u7a7a\u95f4\u768450%\uff0c\u8fd9\u8868\u793a\u4f60\u7684Heap\u5904\u4e8e\u5065\u5eb7\u72b6\u6001\u8bb8\u591aServer\u7aef\u7684Java\u7a0b\u5e8f\u6bcf\u6b21GC\u540e\u6700\u597d\u80fd\u670965%\u7684\u5269\u4f59\u7a7a\u95f4\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u7ecf\u9a8c\u4e4b\u8c08\uff1a<br \/>\n1\uff0eServer\u7aefJVM\u6700\u597d\u5c06-Xms\u548c-Xmx\u8bbe\u4e3a\u76f8\u540c\u503c\u3002\u4e3a\u4e86\u4f18\u5316GC\uff0c\u6700\u597d\u8ba9-Xmn\u503c\u7ea6\u7b49\u4e8e-Xmx\u76841\/3\u3002<br \/>\n2\uff0e\u4e00\u4e2aGUI\u7a0b\u5e8f\u6700\u597d\u662f\u6bcf10\u523020\u79d2\u95f4\u8fd0\u884c\u4e00\u6b21GC\uff0c\u6bcf\u6b21\u5728\u534a\u79d2\u4e4b\u5185\u5b8c\u6210\u3002<\/span><\/p>\n<p><span style=\"font-family: 'Microsoft Yahei';\">\u6ce8\u610f\uff1a<br \/>\n1\uff0e\u589e\u52a0Heap\u7684\u5927\u5c0f\u867d\u7136\u4f1a\u964d\u4f4eGC\u7684\u9891\u7387\uff0c\u4f46\u4e5f\u589e\u52a0\u4e86\u6bcf\u6b21GC\u7684\u65f6\u95f4\u3002\u5e76\u4e14GC\u8fd0\u884c\u65f6\uff0c\u6240\u6709\u7684\u7528\u6237\u7ebf\u7a0b\u5c06\u6682\u505c\uff0c\u4e5f\u5c31\u662fGC\u671f\u95f4\uff0cJava\u5e94\u7528\u7a0b\u5e8f\u4e0d\u505a\u4efb\u4f55\u5de5\u4f5c\u3002<br \/>\n2\uff0eHeap\u5927\u5c0f\u5e76\u4e0d\u51b3\u5b9a\u8fdb\u7a0b\u7684\u5185\u5b58\u4f7f\u7528\u91cf\u3002\u8fdb\u7a0b\u7684\u5185\u5b58\u4f7f\u7528\u91cf\u8981\u5927\u4e8e-Xmx\u5b9a\u4e49\u7684\u503c\uff0c\u56e0\u4e3aJava\u4e3a\u5176\u4ed6\u4efb\u52a1\u5206\u914d\u5185\u5b58\uff0c\u4f8b\u5982\u6bcf\u4e2a\u7ebf\u7a0b\u7684Stack\u7b49\u3002<\/span><\/p>\n<div><span style=\"font-family: 'Microsoft Yahei';\">\u53c2\u8003\uff1a<\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\">http:\/\/blog.csdn.net\/ye1992\/article\/details\/9344807<\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\">http:\/\/www.cnblogs.com\/edwardlauxh\/archive\/2010\/04\/25\/1918602.html<\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\">http:\/\/www.lirongzhen.cn\/?p=1194<\/span><\/div>\n<div><span style=\"font-family: 'Microsoft Yahei';\">http:\/\/www.dgdxs.com\/it\/jishu\/450.html<\/span><\/div>\n<p><em><span style=\"font-family: 'Microsoft Yahei';\">\u8f6c\u8f7d\u8bf7\u6ce8\u660e\u51fa\u5904\uff1a<a href=\"http:\/\/fineyi.com\/\">\u6021\u7136\u4e4b\u4e50 \u2013 FineYi<\/a><\/span><\/em>\t\t<\/p>\n","protected":false},"excerpt":{"rendered":"<p>&nbsp; \u7cfb\u7edfCentOS6.4\u4e0byum\u5b89\u88c5\u4e86tomcat6\u548cjdk1.6, &hellip; <a href=\"http:\/\/www.fineyi.com\/?p=621\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a> <a href=\"http:\/\/www.fineyi.com\/?p=621\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_mi_skip_tracking":false,"footnotes":""},"categories":[3,5],"tags":[19,23,24,25,30,47,48],"class_list":["post-621","post","type-post","status-publish","format-standard","hentry","category-development-tools","category-linux","tag-centos","tag-java","tag-jdk","tag-jdk1-6","tag-linux","tag-tomcat","tag-tomcat6"],"aioseo_notices":[],"_links":{"self":[{"href":"http:\/\/www.fineyi.com\/index.php?rest_route=\/wp\/v2\/posts\/621","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.fineyi.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.fineyi.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.fineyi.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.fineyi.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=621"}],"version-history":[{"count":0,"href":"http:\/\/www.fineyi.com\/index.php?rest_route=\/wp\/v2\/posts\/621\/revisions"}],"wp:attachment":[{"href":"http:\/\/www.fineyi.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=621"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.fineyi.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=621"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.fineyi.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=621"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}