{"id":198,"date":"2021-08-02T17:01:25","date_gmt":"2021-08-02T09:01:25","guid":{"rendered":"http:\/\/blog.nonot.cn\/?p=198"},"modified":"2024-07-08T12:53:47","modified_gmt":"2024-07-08T04:53:47","slug":"%e5%bd%bb%e5%ba%95%e6%90%9e%e6%b8%85%e6%a5%9atomcat%e5%90%af%e5%8a%a8%e6%85%a2%e7%9a%84%e5%8e%9f%e5%9b%a0%e5%8f%8a%e8%a7%a3%e5%86%b3%e6%96%b9%e6%b3%952","status":"publish","type":"post","link":"https:\/\/blog.nonot.cn\/index.php\/2021\/08\/02\/%e5%bd%bb%e5%ba%95%e6%90%9e%e6%b8%85%e6%a5%9atomcat%e5%90%af%e5%8a%a8%e6%85%a2%e7%9a%84%e5%8e%9f%e5%9b%a0%e5%8f%8a%e8%a7%a3%e5%86%b3%e6%96%b9%e6%b3%952\/","title":{"rendered":"\u5f7b\u5e95\u641e\u6e05\u695aTomcat\u542f\u52a8\u6162\u7684\u539f\u56e0\u53ca\u89e3\u51b3\u65b9\u6cd52"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">\u95ee\u9898\u73b0\u8c61<\/h2>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"\/wp-content\/uploads\/replace\/5029e206b46562efdaf1cf9675b686b1.gif\" alt=\"\u5f7b\u5e95\u627e\u5230\u00a0<wbr&gt;Tomcat\u00a0<wbr&gt;\u542f\u52a8\u901f\u5ea6\u6162\u7684\u5143\u51f6\"\/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Tomcat\u542f\u52a8\u5f88\u6162\u3002\u5f00\u59cb\u6211\u4ee5\u4e3a\u662f\u7a0b\u5e8f\u5199\u7684\u95ee\u9898\uff0c\u6240\u4ee5\u628awebapps\u4e0b\u6240\u6709\u7a0b\u5e8f\u90fd\u5220\u9664\u6389\u3002\uff08\u53ea\u4fdd\u7559Tomcat\u81ea\u5e26\uff09\u7075\u5f02\u7684\u4e8b\u60c5\u53d1\u751f\u4e86\uff0cTomcat\u505c\u6b62\u5728\u2014\u2014\u6211\u67e5\u770b\u4e86\u4e00\u4e0b\u8fdb\u7a0b\uff0cTomcat\u6240\u5728\u7684JVM\u8fdb\u7a0b\u5df2\u7ecf\u88ab\u542f\u52a8\u4e86\u6240\u4ee5\u53ef\u4ee5\u6392\u9664\u662fJVM\u9000\u51fa\u5f15\u8d77\u7684\u95ee\u9898\u3002\u90a3\u4e48\u95ee\u9898\u771f\u7684\u5c31\u662fJVM\u56e0\u4e3a\u67d0\u79cd\u539f\u56e0\u88ab\u00a0<strong>\u963b\u585e<\/strong>\u00a0\u4e86\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u5206\u6790<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u95ee\u9898\u6bd4\u8f83\u68d8\u624b\uff0c\u6211\u6392\u9664\u4e86CPU\u3001\u5185\u5b58\u4e0d\u8db3\u5f15\u8d77\u7684\u95ee\u9898\uff1b\u6392\u9664\u4e86\u786c\u76d8\u7a7a\u95f4\u4e0d\u8db3\u5f15\u8d77\u7684\u95ee\u9898\uff1b\u6211\u751a\u81f3\u53bb\u89c2\u5bdf\u4e86\u7f51\u7edcI\/O\u3001\u786c\u76d8I\/O\u60c5\u51b5\uff0c\u90fd\u975e\u5e38\u6b63\u5e38\u3002\u7a0b\u5e8f\u88ab&nbsp;<strong>\u963b\u585e<\/strong>&nbsp;\u4e00\u822c\u6765\u8bf4\u4e00\u5b9a\u662f\u8981\u7b49\u5f85\u67d0\u4e2a\u8d44\u6e90\uff0c\u800c\u73b0\u5728\u7684\u60c5\u51b5\u662f\u6240\u6709\u8d44\u6e90\u90fd\u5145\u8db3\uff0c\u6240\u4ee5\u6211\u51e0\u4e4e\u60f3\u4e0d\u5230\u662f\u4ec0\u4e48\u95ee\u9898\u5f15\u8d77\u7684\u3002&nbsp;\u6211\u5f00\u59cb\u6000\u7591\u662fKVM Hypervisor\u865a\u62df\u5316\u7684\u95ee\u9898\uff08\u7528\u7684\u662f\u865a\u62df\u673a\uff09\u6211\u6539\u53d8\u4e86\u7b56\u7565\u5728VMWare\u5f00\u4e86\u4e24\u53f0\u865a\u62df\u673a\u4e0a\u76f4\u63a5\u4e0b\u8f7dTomcat\u542f\u52a8\u3002\u5176\u4e2d\u4e00\u53f0\u5f88\u5feb\u542f\u52a8\uff0c\u53e6\u4e00\u53f0\u5c45\u7136\u4e5f\u88ab&nbsp;<strong>\u963b\u585e<\/strong>&nbsp;\uff0c\u95ee\u9898\u88ab\u91cd\u73b0\u4e86\u3002&nbsp;\u773c\u770b\u8981\u5728\u7f8e\u5973\u9762\u524d\u4e22\u8138\uff0c\u6211\u5149\u8f89\u4f1f\u5cb8\u7684\u5f62\u8c61\u8981\u8361\u7136\u65e0\u5b58\u3002\u8fd9\u79cd\u60c5\u51b5\u4e0b\u6211\u4e0d\u80fd\u53bb\u201c\u64b8\u201d\u4ee3\u7801\u5427\uff1f\u51b5\u4e14Tomcat\u90a3\u4e48\u591a\u4eba\u7528\uff0c\u771f\u6709\u8fd9\u4e48\u660e\u663e\u7684Bug\u65e9\u5c31\u70b8\u5f00\u9505\u4e86\u3002\uff08Tomcat\u8fd8\u662f\u5f88\u9760\u8c31\u7684\u4e0d\u50cfxxxxStack\u90a3\u4e48\u72d7\u5c4e\uff09\u4ed4\u7ec6\u60f3\u60f3\u6211\u9700\u8981\u627e\u5230Tomcat\u505c\u6b62\u5728\u4e86\u54ea\u91cc\uff1f\u4ee3\u7801\u91cc\u53d1\u751f\u4e86\u4ec0\u4e48\u4e8b\u60c5\uff0c\u4f46\u662f\u6211\u53c8\u4e0d\u53ef\u80fd\u53bb\u64b8\u4ee3\u7801\u3002\u65e0\u53ef\u5948\u4f55\u7684\u60c5\u51b5\u4e0b\u6211\u51b3\u5b9a\u8bd5\u4e00\u4e0b&nbsp;&nbsp;<strong>strace<\/strong>&nbsp;\uff0c\u8fd9\u662f\u4e00\u4e2a&nbsp;<strong>\u8ddf\u8e2a\u7cfb\u7edf\u8c03\u7528(System Call)\u7684\u5de5\u5177<\/strong>&nbsp;\uff0c\u65e0\u8bba\u662fJava\u8fd8\u662fPyhton\u5f88\u591a\u8d44\u6e90\u7533\u8bf7\u90fd\u4f1a\u53d8\u6210\u90fd\u4f1a\u53d8\u6210System Call\u3002\uff08\u6bd4\u5982\u6253\u5f00\u6587\u4ef6\u3001\u65b0\u5efa\u7ebf\u7a0b\u3001\u8bfb\u5199\u6570\u636e\u3001\u7b49\u5f85I\/O\uff09\u901a\u8fc7\u8fd9\u4e2a\u5de5\u5177\u6211\u81f3\u5c11\u53ef\u4ee5\u77e5\u9053&nbsp;<strong>Tomcat\u662f\u505c\u6b62\u5728\u54ea\u4e2aSystem Call\u4e0a\u7684<\/strong>&nbsp;\uff0c\u8fd9\u6837\u53ef\u4ee5\u65b9\u4fbf\u6211\u63a8\u65ad\u51fa\u95ee\u9898\u7684\u539f\u56e0\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">strace -f -o strace.out .\/catalina.sh&nbsp;run<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">strace\u6709\u5f88\u591a\u53c2\u6570\uff0c\u6211\u7528\u4e86\u4e8c\u4e2a\u53c2\u6570<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>-f \u8ddf\u8e2afork\u7684\u5b50\u8fdb\u7a0b\uff0c\u901a\u4fd7\u7684\u8bf4\u4f1a\u8ddf\u8e2a\u6240\u6709\u7ebf\u7a0b\u7684\u7cfb\u7edf\u8c03\u7528<\/li><li>-o\u628a\u5185\u5bb9\u8f93\u51fa\u5230\u6587\u4ef6<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"\/wp-content\/uploads\/replace\/5029e206b46562efdaf1cf9675b686b1.gif\" alt=\"\u5f7b\u5e95\u627e\u5230\u00a0<wbr&gt;Tomcat\u00a0<wbr&gt;\u542f\u52a8\u901f\u5ea6\u6162\u7684\u5143\u51f6\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"\/wp-content\/uploads\/replace\/5029e206b46562efdaf1cf9675b686b1.gif\" alt=\"\u5f7b\u5e95\u627e\u5230\u00a0<wbr&gt;Tomcat\u00a0<wbr&gt;\u542f\u52a8\u901f\u5ea6\u6162\u7684\u5143\u51f6\"\/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u5176\u4ed6\u53c2\u6570\u8bf7\u81ea\u884c\u641c\u7d22&nbsp;\u4e0b\u9762\u5206\u6790strace.out\u6587\u4ef6\uff0c\u5206\u6790\u7684\u65b9\u6cd5\u662f\u4ece\u4e0b\u5f80\u4e0a\uff08\u88ab&nbsp;<strong>\u963b\u585e<\/strong>&nbsp;\u7684\u5730\u65b9\u80af\u5b9a\u662f\u5728\u6700\u540e\u54af\uff09\u3002\u9996\u5148\u6211\u4eec\u9700\u8981\u53bb\u6389Tomcat\u505c\u6b62\u5f15\u8d77\u7684System Call\uff0c\u5b83\u4eec\u4e0d\u662f\u6211\u4eec\u9700\u8981\u7684\u3002\u4ece\u540e\u5f80\u524d\u641c\u7d22\u627e\u5230&nbsp;<code>SIGINT<\/code>\u7ea2\u8272\u90e8\u5206\u4ee5\u4e0a\u5c31\u662f\u5f15\u8d77\u963b\u585e\u7684\u7cfb\u7edf\u8c03\u7528\u4e86\uff0c\u4e0a\u9762\u6709\u4e00\u5927\u5806\u4e00\u5927\u5806\u7684&nbsp;<code>futex<\/code>&nbsp;\u7684\u8c03\u7528\uff0c\u5b83\u662fLinux\u4e2d\u7684\u4e00\u79cd\u8f7b\u91cf\u7ea7\u7684\u540c\u6b65\u65b9\u6cd5\uff0c\u6240\u4ee5\u6211\u4eec\u53ef\u4ee5\u5224\u65ad\u51fa\u6700\u4e0a\u9762\u80af\u5b9a\u662f\u6709\u67d0\u4e2aSystem Call\u5c31\u662f&nbsp;<strong>\u963b\u585e<\/strong>&nbsp;\u7684\u771f\u6b63\u5143\u51f6\u3002\u8df3\u8fc7\u6240\u6709\u7684&nbsp;<code>futex<\/code>&nbsp;\uff1a\u8fd9\u4e2a&nbsp;<code>read<\/code>&nbsp;\u5c31\u662f\u5f15\u8d77\u540e\u9762\u4e00\u4e32&nbsp;<code>futex<\/code>&nbsp;\u7684\u771f\u6b63\u539f\u56e0\uff0c&nbsp;<strong>strace<\/strong>&nbsp;\u975e\u5e38\u806a\u660e\u5b83\u4e0d\u4ec5\u4ec5\u7ed9\u51fa\u4e86System Call\u8fd8\u7ed9\u51fa\u4e86\u4f20\u9012\u7684\u53c2\u6570\u548c\u8fd4\u56de\u503c\uff0cread\u8bfb\u53d6\u7684\u662f51\u53f7\u6587\u4ef6\u53e5\u67c4\uff0c\u6ca1\u6709\u8fd4\u56de\u6210\u529f(unfinished)\u3002&nbsp;\u987a\u7740\u8fd9\u6761\u8def\uff0c\u6211\u4eec\u770b\u4e00\u4e0b51\u53f7\u6587\u4ef6\u53e5\u67c4\u662f\u4ec0\u4e48&nbsp;<strong>\/dev\/random<\/strong>&nbsp;\u662fLinux\u4e0b\u7684\u968f\u673a\u51fd\u6570\u751f\u6210\u5668\uff0c\u8bfb\u53d6\u5b83\u76f8\u5f53\u4e8e\u751f\u6210\u968f\u673a\u6570\u5b57\u3002\u641c\u7d22\u5b83\uff0c\u7b2c\u4e00\u4e2a\u662fwiki&nbsp;\u81f3\u6b64\u4f3c\u4e4e\u4e00\u5207\u771f\u76f8\u5927\u767d\u4e86\uff0c\/dev\/random\u4f1a\u6839\u636e&nbsp;<strong>\u566a\u97f3<\/strong>\u4ea7\u751f\u968f\u673a\u6570\uff0c\u5982\u679c&nbsp;<strong>\u566a\u97f3<\/strong>&nbsp;\u4e0d\u591f\u5b83\u5c31\u4f1a\u963b\u585e\u3002Linux\u662f\u901a\u8fc7I\/O\uff0c\u952e\u76d8\u7ec8\u7aef\u3001\u5185\u5b58\u4f7f\u7528\u91cf\u3001CPU\u5229\u7528\u7387\u7b49\u65b9\u5f0f\u6765\u6536\u96c6&nbsp;<strong>\u566a\u97f3<\/strong>&nbsp;\u7684\uff0c\u5982\u679c&nbsp;<strong>\u566a\u97f3<\/strong>&nbsp;\u4e0d\u591f\u751f\u6210\u968f\u673a\u6570\u7684\u65f6\u5019\u5c31\u4f1a\u88ab&nbsp;<strong>\u963b\u585e<\/strong>&nbsp;\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u6df1\u5165\u5206\u6790<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u679c\u7528Tomcat \/dev\/random\u4f5c\u4e3a\u5173\u952e\u5b57\u57fa\u672c\u4e0a\u5c31\u80fd\u591f\u56de\u7b54\u6211\u4eec\u7684\u7591\u60d1\u4e86\u3002Tocmat\u7684Session ID\u662f\u901a\u8fc7SHA1\u7b97\u6cd5\u8ba1\u7b97\u5f97\u5230\u7684\uff0c\u8ba1\u7b97Session ID\u7684\u65f6\u5019\u5fc5\u987b\u6709\u4e00\u4e2a\u5bc6\u94a5\u3002\u4e3a\u4e86\u63d0\u9ad8\u5b89\u5168\u6027Tomcat\u5728\u542f\u52a8\u7684\u65f6\u5019\u56de\u901a\u8fc7\u968f\u673a\u751f\u6210\u4e00\u4e2a\u5bc6\u94a5\u3002&nbsp;\u5728 http:\/\/wiki.apache.org\/tomcat\/HowTo\/FasterStartUp (Entropy Source\u90e8\u5206)\u6709\u4e00\u6bb5\u89e3\u91ca\u3002stackoverflow\u4e0a\u9762\u4e5f\u6709\u4e00\u5927\u6279\u8fd9\u65b9\u9762\u7684\u8bf4\u660e\uff0c\u6240\u4ee5\u8fd9\u91cc\u5c31\u4e0d\u518d\u591a\u505a\u4ecb\u7ecd\u3002&nbsp;\u660e\u767d\u4e86\u95ee\u9898\u7684\u539f\u56e0\u89e3\u51b3\u8d77\u6765\u5c31\u975e\u5e38\u7b80\u5355\u4e86\u2014\u2014\u66ff\u6362\/dev\/random\u4e3a\/dev\/unrandom\uff0c\u7528\u4f2a\u968f\u673a\u51fd\u6570\u751f\u6210\u5668(\/dev\/urandom)\u6765\u66ff\u4ee3\u968f\u673a\u51fd\u6570\u751f\u6210\u5668(\/dev\/random)\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u901a\u8fc7\u4fee\u6539Tomcat\u542f\u52a8\u6587\u4ef6catalina.sh\u6587\u4ef6\u4e2d\u52a0\u5165&nbsp;<\/li><li>\u6b64\u884c\u4ee3\u7801-Djava.security.egd=file:\/dev\/urandom<\/li><li>\u901a\u8fc7\u4fee\u6539JRE\u4e2d\u7684$JAVA_PATH\/jre\/lib\/security\/java.security\u6587\u4ef6&nbsp;<code>securerandom.source=file:\/dev\/urandom<\/code><\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f53\u7136JVM\u7684\u5f00\u53d1\u8005\u4e0d\u662f\u50bb\u74dc\uff0cTomcat\u7684\u5f00\u53d1\u8005\u4e5f\u4e0d\u662f\u4e8c\u767e\u4e94\u3002\u4ed6\u4eec\u4e4b\u6240\u4ee5\u6ca1\u6709\u9009\u62e9\/dev\/urandom\u662f\u4e3a\u4e86\u63d0\u9ad8\u7cfb\u7edf\u7684\u5b89\u5168\u6027\uff0c\/dev\/urandom\u5e76\u4e0d\u662f\u771f\u6b63\u7684\u968f\u673a\u884c\u4e3a\u3002\uff08\u5176\u5b9e\u4e00\u822c\u60c5\u51b5\u4e0b\/dev\/urandom\u4e5f\u662f\u8db3\u591f\u5b89\u5168\u7684\u4e0d\u592a\u5bb9\u6613\u88ab\u201c\u91cd\u590d\u201d\uff09<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u5f7b\u5e95\u89e3\u51b3\u95ee\u9898<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0a\u9762\u4ecb\u7ecd\u7684\u4e24\u79cd\u65b9\u5f0f\u90fd\u662f\u7528\/dev\/urandom\u66ff\u6362\/dev\/random\uff0c\u5176\u5b9e\u8fd8\u6709\u7b2c\u4e09\u79cd\u65b9\u5f0f\u2014\u2014\u589e\u5927\/dev\/random\u7684\u71b5\u6c60\u3002\u95ee\u9898\u7684\u539f\u56e0\u662f\u7531\u4e8e\u71b5\u6c60\u4e0d\u591f\u5927\uff0c\u6240\u4ee5\u589e\u5927\u5b83\u662f\u6700\u5f7b\u5e95\u7684\u65b9\u6cd5\u3002&nbsp;\u901a\u8fc7&nbsp;<code>cat \/proc\/sys\/kernel\/random\/entropy_avail<\/code>&nbsp;\u6211\u4eec\u53ef\u4ee5\u67e5\u770b\u73b0\u5728\u7684\u71b5\u6c60\u5927\u5c0f\uff1b\u6211\u4eec\u9700\u8981\u627e\u5230\u4e00\u79cd\u65b9\u5f0f\u6765\u63d0\u9ad8\u8fd9\u4e2a\u503c\u5c31\u884c\u4e86\u3002\u5982\u679c\u4f60\u7684CPU\u5e26\u6709DRNG\u7279\u6027\uff0c\u53ef\u4ee5\u5145\u5206\u5229\u7528\u786c\u4ef6\u6765\u63d0\u9ad8\u71b5\u6c60\u4ea7\u751f\u7684\u901f\u5ea6 \u3002\u901a\u8fc7&nbsp;<code>cat \/proc\/cpuinfo | grep rdrand<\/code>&nbsp;\u53ef\u4ee5\u67e5\u770b\u81ea\u5df1\u7684CPU\u662f\u5426\u652f\u6301\uff0c\u4e00\u822c\u6765\u8bf4Intel\u7684Ivy_Bridge\u67b6\u6784\u7684CPU\u90fd\u652f\u6301\uff08i3\u3001i5\u9700\u8981\u6ce8\u610f\u662f\u5426\u91c7\u7528\u8be5\u79cd\u67b6\u6784\uff0ci7\u548cxeon\u57fa\u672c\u4e0a\u90fd\u652f\u6301\uff09\uff1bAMD\u7684CPU\u57282015\u5e74\u4ee5\u540e\u751f\u6210\u7684\u90fd\u652f\u6301\u3002\uff08\u5982\u679c\u4f60\u662f\u865a\u62df\u673a\u9700\u8981\u5f00\u542f\u989d\u5916\u7684\u53c2\u6570)\u3002\u5982\u679c\u4f60\u7684\u786c\u4ef6\u4e0d\u652f\u6301\uff0c\u4e5f\u6ca1\u6709\u5173\u7cfb\uff0c\u6211\u4eec\u53ef\u4ee5\u8ba9\/dev\/unrandom\u6765\u505a\u201c\u71b5\u6e90\u201d\u3002&nbsp;\u4ee5Centos7\u4e3a\u4f8b\uff0c<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><code>yum install rngd-tools<\/code>&nbsp;\u5b89\u88c5rngd\u670d\u52a1\uff08\u71b5\u670d\u52a1\uff09<\/li><li><code>systemctl start rngd<\/code>&nbsp;\u542f\u52a8\u670d\u52a1\u5982\u679c\u4f60\u7684CPU\u4e0d\u652f\u6301DRNG\u7279\u6027\u6216\u8005\u50cf\u6211\u4e00\u6837\u4f7f\u7528\u865a\u62df\u673a\uff0c\u53ef\u4ee5\u4f7f\u7528\/dev\/unrandom\u6765\u6a21\u62df\u3002<\/li><li><code>cp \/usr\/lib\/systemd\/system\/rngd.service \/etc\/systemd\/system<\/code><\/li><li>\u7f16\u8f91&nbsp;<code>\/etc\/systemd\/system\/rngd.service<\/code>&nbsp;service\u5c0f\u7ed3\uff0c&nbsp;<code>ExecStart=\/sbin\/rngd -f -r \/dev\/urandom<\/code><\/li><li><code>systemctl daemon-reload<\/code>&nbsp;\u91cd\u65b0\u8f7d\u5165\u670d\u52a1<\/li><li><code>systemctl restart rngd<\/code>&nbsp;\u91cd\u542f\u670d\u52a1<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ecf\u8fc7\u4e0a\u9762\u7684\u4fee\u6539\uff0c\u6211\u4eec\u518d\u89c2\u5bdf&nbsp;<code>\/proc\/sys\/kernel\/random\/entropy_avail<\/code>&nbsp;\u57fa\u672c\u4e0a\u57283000\u5de6\u53f3\u3002\u6211\u4eec\u53ef\u4ee5\u6d4b\u8bd5\u4e00\u4e0b\u968f\u673a\u6570\u7684\u751f\u6210\u901f\u5ea6<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><code>watch -n 1 cat \/proc\/sys\/kernel\/random\/entropy_avail<\/code>&nbsp;\u89c2\u5bdf\u8fd9\u4e2a\u503c<\/li><li>\u65b0\u6253\u5f00\u4e00\u4e2ashell\uff0c\u7528dd\u547d\u4ee4\u6d4b\u8bd5\u968f\u673a\u6570\u3002&nbsp;<code>dd if=\/dev\/random of=random.dat count=40960<\/code><\/li><\/ul>\n\n\n\n<pre class=\"wp-block-preformatted\">[root@localhost&nbsp;bin]# dd if=\/dev\/random of=random.dat count=40960\n\u8bb0\u5f55\u4e860+40960 \u7684\u8bfb\u5165\n\u8bb0\u5f55\u4e866004+1 \u7684\u5199\u51fa\n3074362\u5b57\u8282(3.1&nbsp;MB)\u5df2\u590d\u5236\uff0c5.01017 \u79d2\uff0c614 kB\/\u79d2<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">5\u79d2\u4ea7\u751f\u4e8640960\u4e2a\u968f\u673a\u6570\uff0c\/proc\/sys\/kernel\/random\/entropy_avail\u4f1a\u6709\u5267\u70c8\u7684\u53d8\u5316\uff0c\u6240\u6709\u968f\u673a\u6570\u4ea7\u751f\u4e4b\u540e\u5b83\u53c8\u4f1a\u4fdd\u6301\u57283000\u5de6\u53f3\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u9009\u62e9\u54ea\u79cd\u89e3\u51b3\u65b9\u6cd5<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e2a\u4eba\u5efa\u8bae\u9009\u62e9\u7b2c\u4e09\u79cd\u65b9\u5f0f\uff0c\u71b5\u6c60\u4e0d\u4ec5\u4ec5Tomcat\u7528\uff0cLinux\u4e0b\u7684\u6240\u6709\u5e94\u7528\u7a0b\u5e8f\u4ea7\u751f\u968f\u673a\u6570\u90fd\u4f1a\u7528\u5230\u8fd9\u4e2a\uff0c\u6240\u4ee5\u4e0d\u4ec5\u4ec5\u662fTomcat\u53ef\u80fd\u88ab&nbsp;<strong>\u963b\u585e<\/strong>&nbsp;\u3002\u5982\u679c\u4f60\u641c\u7d22\u4f1a\u53d1\u73b0Apache\u3001Nginx\u3001OpenSSL\u90fd\u88ab\u8fd9\u4e2a\u95ee\u9898&nbsp;<strong>\u5751\u8fc7<\/strong>&nbsp;\u3002\u5982\u679c\u6211\u4eec\u901a\u8fc7\u4fee\u6539Java\u7684\u914d\u7f6e\u6765\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u5176\u5b9e\u53ea\u662f\u89e3\u51b3Java\u5e94\u7528\u7a0b\u5e8f\u7684\u95ee\u9898\uff0c\u53ea\u80fd\u662f\u6cbb\u6807\u4e0d\u6cbb\u672c\u3002\u6839\u6cbb\u7684\u65b9\u6cd5\u5e94\u8be5\u662f\u901a\u8fc7&nbsp;<code>rngd<\/code>&nbsp;\u63d0\u9ad8\u968f\u673a\u6570\u751f\u6210\u7684\u901f\u5ea6\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u603b\u7ed3<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ecf\u9a8c\u4e0d\u662f\u7ecf\u5386\u3002\u7528\u522b\u4eba\u7684\u7ecf\u9a8c\u89e3\u51b3\u4e00\u4e2a\u95ee\u9898\u4e0d\u96be\uff0c\u96be\u7684\u662f\u81ea\u5df1\u4ece\u5934\u8d70\u4e00\u904d\u8fd9\u6761\u8def\uff0c\u66f4\u52a0\u96be\u7684\u662f\u63a8\u7ffb\u524d\u4eba\u7684\u7ecf\u9a8c\u5bf9\u4e00\u4e2a\u95ee\u9898\u80fd\u591f\u6709\u81ea\u5df1\u7684\u770b\u6cd5\u548c\u9886\u609f\u3002&nbsp;\u8fd9\u4e2a\u6848\u4f8b\u52a0\u6df1\u4e86\u6211\u5bf9&nbsp;<code>strace<\/code>&nbsp;\u7684\u7406\u89e3\uff0c\u5bf9\u4e8e&nbsp;<code>\u7a7a\u4e2d\u52a0\u6cb9<\/code>&nbsp;\u8fd9\u79cd\u7c7b\u578b\u7684\u7cfb\u7edf\u8c03\u8bd5\u6709\u4e86\u81ea\u5df1\u7684\u7ecf\u9a8c\uff1b\u901a\u8fc7\u5bf9\u539f\u56e0\u7684\u6df1\u5165\u5206\u6790\u6211\u627e\u5230\u4e86&nbsp;<strong>\u66f4\u597d\u7684\u529e\u6cd5<\/strong>\u3002\u8fd9\u5c31\u662f&nbsp;<strong>\u5eb7\u5fb7\u7cbe\u795e<\/strong>&nbsp;\u2014\u2014\u601d\u8003\u3001\u6279\u5224\u3001\u7406\u6027\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u5982\u4f55\u91cd\u73b0\u6545\u969c<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u53ef\u4ee5\u5f88\u5bb9\u6613\u7684\u91cd\u73b0\u6587\u7ae0\u4e2d\u63cf\u8ff0\u7684\u6545\u969c<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><code>systemctl stop rngd<\/code>&nbsp;\u505c\u6b62rngd\u670d\u52a1\uff08\u5982\u679c\u4f60\u6709\u542f\u52a8rngd\uff09<\/li><li>\u67e5\u770b\u5f53\u524d\u71b5\u6c60\u7684\u5927\u5c0f&nbsp;<code>cat \/proc\/sys\/kernel\/random\/entropy_avail<\/code><\/li><li><code>head -c1024 \/dev\/random<\/code>&nbsp;\uff0c\u5f3a\u5236\u6d88\u8d391024\u4e2a\u968f\u673a\u6570\uff0c\u7cfb\u7edf\u4f1a\u957f\u65f6\u95f4\u6ca1\u6709\u53cd\u5e94\u3002\u76f4\u63a5ctrl+c<\/li><li>\u518d\u6b21\u67e5\u770b\u71b5\u6c60\u7684\u5927\u5c0f&nbsp;<code>cat \/proc\/sys\/kernel\/random\/entropy_avail<\/code>&nbsp;\uff0c\u4fdd\u8bc1\u5b83\u7684\u5927\u5c0f\u5728\u5c3d\u53ef\u80fd\u7684\u5c0f<\/li><li>\u542f\u52a8tomcat\uff0c\u4f1a\u53d1\u73b0\u957f\u65f6\u95f4\u5f88\u957f\u65f6\u95f4\u7684\u7b49\u5f85<\/li><\/ul>\n","protected":false},"excerpt":{"rendered":"<p>\u95ee\u9898\u73b0\u8c61 Tomcat\u542f\u52a8\u5f88\u6162\u3002\u5f00\u59cb\u6211\u4ee5\u4e3a\u662f\u7a0b\u5e8f\u5199\u7684\u95ee\u9898\uff0c\u6240&hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9],"tags":[],"class_list":["post-198","post","type-post","status-publish","format-standard","hentry","category-tomcat"],"_links":{"self":[{"href":"https:\/\/blog.nonot.cn\/index.php\/wp-json\/wp\/v2\/posts\/198","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.nonot.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.nonot.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.nonot.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.nonot.cn\/index.php\/wp-json\/wp\/v2\/comments?post=198"}],"version-history":[{"count":1,"href":"https:\/\/blog.nonot.cn\/index.php\/wp-json\/wp\/v2\/posts\/198\/revisions"}],"predecessor-version":[{"id":1214,"href":"https:\/\/blog.nonot.cn\/index.php\/wp-json\/wp\/v2\/posts\/198\/revisions\/1214"}],"wp:attachment":[{"href":"https:\/\/blog.nonot.cn\/index.php\/wp-json\/wp\/v2\/media?parent=198"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.nonot.cn\/index.php\/wp-json\/wp\/v2\/categories?post=198"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.nonot.cn\/index.php\/wp-json\/wp\/v2\/tags?post=198"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}