{"id":3343,"date":"2017-06-08T21:37:43","date_gmt":"2017-06-08T13:37:43","guid":{"rendered":"https:\/\/ixyzero.com\/blog\/?p=3343"},"modified":"2017-06-08T21:37:43","modified_gmt":"2017-06-08T13:37:43","slug":"collect%e6%80%a7%e8%83%bd%e8%b0%83%e4%bc%98%e6%94%bb%e7%95%a5","status":"publish","type":"post","link":"https:\/\/ixyzero.com\/blog\/archives\/3343.html","title":{"rendered":"[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565"},"content":{"rendered":"<p>=Start=<\/p>\n<h4 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u7f18\u7531\uff1a\">\u7f18\u7531\uff1a<\/h4>\n<p>\u672c\u6587\u662f\u9177\u58f3\u535a\u4e3b\u9648\u7693\u51e0\u5e74\u524d(2012\u5e7406\u670820\u65e5)\u5199\u7684\u300c<a class=\"external-link\" href=\"http:\/\/coolshell.cn\/articles\/7490.html\" rel=\"nofollow\">\u6027\u80fd\u8c03\u4f18\u653b\u7565<\/a>\u300d\uff0c\u65f6\u9694\u591a\u5e74\u518d\u770b\uff0c\u4f9d\u65e7\u5f88\u6709\u542f\u53d1\u6027\u3002\u5728\u5f81\u5f97\u4f5c\u8005\u540c\u610f\u7684\u60c5\u51b5\u4e0b\uff0c\u8f6c\u8f7d\u81f3\u6b64\uff0c\u65b9\u4fbf\u7ecf\u5e38\u89c2\u6469\u5b66\u4e60\u3002<\/p>\n<p>\u539f\u6587\u94fe\u63a5\uff1a<a class=\"external-link\" href=\"http:\/\/coolshell.cn\/articles\/7490.html\" rel=\"nofollow\">http:\/\/coolshell.cn\/articles\/7490.html<\/a><\/p>\n<h4 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u6b63\u6587\uff1a\">\u6b63\u6587\uff1a<\/h4>\n<p>\u5173\u4e8e\u6027\u80fd\u4f18\u5316\u8fd9\u662f\u4e00\u4e2a\u6bd4\u8f83\u5927\u7684\u8bdd\u9898\uff0c\u5728\u300a<a class=\"external-link\" title=\"\u753112306.cn\u8c08\u8c08\u7f51\u7ad9\u6027\u80fd\u6280\u672f\" href=\"http:\/\/coolshell.cn\/articles\/6470.html\" rel=\"nofollow\">\u753112306.cn\u8c08\u8c08\u7f51\u7ad9\u6027\u80fd\u6280\u672f<\/a>\u300b\u4e2d\u6211\u4ece\u4e1a\u52a1\u548c\u8bbe\u8ba1\u4e0a\u8bf4\u8fc7\u4e00\u4e9b\u53ef\u7528\u7684\u6280\u672f\u4ee5\u53ca\u90a3\u4e9b\u6280\u672f\u7684\u4f18\u7f3a\u70b9\uff0c\u4eca\u5929\uff0c\u60f3\u4ece\u4e00\u4e9b\u6280\u672f\u7ec6\u8282\u4e0a\u8c08\u8c08\u6027\u80fd\u4f18\u5316\uff0c\u4e3b\u8981\u662f\u4e00\u4e9b\u4ee3\u7801\u7ea7\u522b\u7684\u6280\u672f\u548c\u65b9\u6cd5\u3002<strong>\u672c\u6587\u7684\u4e1c\u897f\u662f\u6211\u7684\u4e00\u4e9b\u7ecf\u9a8c\u548c\u77e5\u8bc6\uff0c\u5e76\u4e0d\u4e00\u5b9a\u5168\u5bf9\uff0c\u5e0c\u671b\u5927\u5bb6\u6307\u6b63\u548c\u8865\u5145<\/strong>\u3002<\/p>\n<p>\u5728\u5f00\u59cb\u8fd9\u7bc7\u6587\u7ae0\u4e4b\u524d\uff0c\u5927\u5bb6\u53ef\u4ee5\u79fb\u6b65\u53bb\u770b\u4e00\u4e0b\u9177\u58f3\u4ee5\u524d\u53d1\u8868\u7684\u300a<a class=\"external-link\" title=\"\u4ee3\u7801\u4f18\u5316\u6982\u8981\" href=\"http:\/\/coolshell.cn\/articles\/2967.html\" rel=\"nofollow\">\u4ee3\u7801\u4f18\u5316\u6982\u8981<\/a>\u300b\uff0c\u8fd9\u7bc7\u6587\u7ae0\u57fa\u672c\u4e0a\u544a\u8bc9\u4f60\u2014\u2014<strong>\u8981\u8fdb\u884c\u4f18\u5316\uff0c\u5148\u5f97\u627e\u5230\u6027\u80fd\u74f6\u9888<\/strong>\uff01 \u4f46\u662f\u5728\u8bb2\u5982\u4f55\u5b9a\u4f4d\u7cfb\u7edf\u6027\u80fd\u74f6\u52b2\u4e4b\u524d\uff0c\u8bf7\u8ba9\u6211\u8bb2\u4e00\u4e0b\u7cfb\u7edf\u6027\u80fd\u7684\u5b9a\u4e49\u548c\u6d4b\u8bd5\uff0c\u56e0\u4e3a\u6ca1\u6709\u8fd9\u4e24\u4ef6\u4e8b\uff0c\u540e\u9762\u7684\u5b9a\u4f4d\u548c\u4f18\u5316\u65e0\u4ece\u8c08\u8d77\u3002<\/p>\n<h3 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u7cfb\u7edf\u6027\u80fd\u5b9a\u4e49\">\u7cfb\u7edf\u6027\u80fd\u5b9a\u4e49<\/h3>\n<p>\u8ba9\u6211\u4eec\u5148\u6765\u8bf4\u8bf4\u5982\u4f55\u4ec0\u4e48\u662f\u7cfb\u7edf\u6027\u80fd\u3002\u8fd9\u4e2a\u5b9a\u4e49\u975e\u5e38\u5173\u952e\uff0c\u5982\u679c\u6211\u4eec\u4e0d\u6e05\u695a\u4ec0\u4e48\u662f\u7cfb\u7edf\u6027\u80fd\uff0c\u90a3\u4e48\u6211\u4eec\u5c06\u65e0\u6cd5\u5b9a\u4f4d\u4e4b\u3002\u6211\u89c1\u8fc7\u5f88\u591a\u670b\u53cb\u4f1a\u89c9\u5f97\u8fd9\u5f88\u5bb9\u6613\uff0c\u4f46\u662f\u4ed4\u7ec6\u4e00\u95ee\uff0c\u5176\u5b9e\u4ed6\u4eec\u5e76\u6ca1\u6709\u4e00\u4e2a\u6bd4\u8f83\u7cfb\u7edf\u7684\u65b9\u6cd5\uff0c\u6240\u4ee5\uff0c\u5728\u8fd9\u91cc\u6211\u60f3\u544a\u8bc9\u5927\u5bb6\u5982\u4f55\u7cfb\u7edf\u5730\u6765\u5b9a\u4f4d\u6027\u80fd\u3002 \u603b\u4f53\u6765\u8bf4\uff0c\u7cfb\u7edf\u6027\u80fd\u5c31\u662f\u4e24\u4e2a\u4e8b\uff1a<\/p>\n<ol class=\"list-paddingleft-2\">\n<li><strong>Throughput<\/strong>\uff0c\u541e\u5410\u91cf\u3002\u4e5f\u5c31\u662f\u6bcf\u79d2\u949f\u53ef\u4ee5\u5904\u7406\u7684\u8bf7\u6c42\u6570\uff0c\u4efb\u52a1\u6570\u3002<\/li>\n<li><strong>Latency<\/strong>\uff0c \u7cfb\u7edf\u5ef6\u8fdf\u3002\u4e5f\u5c31\u662f\u7cfb\u7edf\u5728\u5904\u7406\u4e00\u4e2a\u8bf7\u6c42\u6216\u4e00\u4e2a\u4efb\u52a1\u65f6\u7684\u5ef6\u8fdf\u3002<\/li>\n<\/ol>\n<p>\u4e00\u822c\u6765\u8bf4\uff0c\u4e00\u4e2a\u7cfb\u7edf\u7684\u6027\u80fd\u53d7\u5230\u8fd9\u4e24\u4e2a\u6761\u4ef6\u7684\u7ea6\u675f\uff0c\u7f3a\u4e00\u4e0d\u53ef\u3002\u6bd4\u5982\uff0c\u6211\u7684\u7cfb\u7edf\u53ef\u4ee5\u9876\u5f97\u4f4f\u4e00\u767e\u4e07\u7684\u5e76\u53d1\uff0c\u4f46\u662f\u7cfb\u7edf\u7684\u5ef6\u8fdf\u662f 2 \u5206\u949f\u4ee5\u4e0a\uff0c\u90a3\u4e48\uff0c\u8fd9\u4e2a\u4e00\u767e\u4e07\u7684\u8d1f\u8f7d\u6beb\u65e0\u610f\u4e49\u3002\u7cfb\u7edf\u5ef6\u8fdf\u5f88\u77ed\uff0c\u4f46\u662f\u541e\u5410\u91cf\u5f88\u4f4e\uff0c\u540c\u6837\u6ca1\u6709\u610f\u4e49\u3002\u6240\u4ee5\uff0c\u4e00\u4e2a\u597d\u7684\u7cfb\u7edf\u7684\u6027\u80fd\u6d4b\u8bd5\u5fc5\u7136\u53d7\u5230\u8fd9\u4e24\u4e2a\u6761\u4ef6\u7684\u540c\u65f6\u4f5c\u7528\u3002 \u6709\u7ecf\u9a8c\u7684\u670b\u53cb\u4e00\u5b9a\u77e5\u9053\uff0c\u8fd9\u4e24\u4e2a\u4e1c\u897f\u7684\u4e00\u4e9b\u5173\u7cfb\uff1a<\/p>\n<ul class=\"list-paddingleft-2\">\n<li><strong>Throughput \u8d8a\u5927\uff0cLatency \u4f1a\u8d8a\u5dee<\/strong>\u3002\u56e0\u4e3a\u8bf7\u6c42\u91cf\u8fc7\u5927\uff0c\u7cfb\u7edf\u592a\u7e41\u5fd9\uff0c\u6240\u4ee5\u54cd\u5e94\u901f\u5ea6\u81ea\u7136\u4f1a\u4f4e\u3002<\/li>\n<li><strong>Latency \u8d8a\u597d\uff0c\u80fd\u652f\u6301\u7684 Throughput \u5c31\u4f1a\u8d8a\u9ad8<\/strong>\u3002\u56e0\u4e3a Latency \u77ed\u8bf4\u660e\u5904\u7406\u901f\u5ea6\u5feb\uff0c\u4e8e\u662f\u5c31\u53ef\u4ee5\u5904\u7406\u66f4\u591a\u7684\u8bf7\u6c42\u3002<\/li>\n<\/ul>\n<h3 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u7cfb\u7edf\u6027\u80fd\u6d4b\u8bd5\">\u7cfb\u7edf\u6027\u80fd\u6d4b\u8bd5<\/h3>\n<p>\u7ecf\u8fc7\u4e0a\u8ff0\u7684\u8bf4\u660e\uff0c\u6211\u4eec\u77e5\u9053\u8981\u6d4b\u8bd5\u7cfb\u7edf\u7684\u6027\u80fd\uff0c\u9700\u8981\u6211\u4eec\u6536\u96c6\u7cfb\u7edf\u7684 Throughput \u548c Latency \u8fd9\u4e24\u4e2a\u503c\u3002<\/p>\n<ul class=\"list-paddingleft-2\">\n<li>\u9996\u5148\uff0c<strong>\u9700\u8981\u5b9a\u4e49 Latency \u8fd9\u4e2a\u503c<\/strong>\uff0c\u6bd4\u5982\u8bf4\uff0c\u5bf9\u4e8e\u7f51\u7ad9\u7cfb\u7edf\u54cd\u5e94\u65f6\u95f4\u5fc5\u9700\u662f 5 \u79d2\u4ee5\u5185\uff08\u5bf9\u4e8e\u67d0\u4e9b\u5b9e\u65f6\u7cfb\u7edf\u53ef\u80fd\u9700\u8981\u5b9a\u4e49\u7684\u66f4\u77ed\uff0c\u6bd4\u5982 5ms \u4ee5\u5185\uff0c\u8fd9\u4e2a\u66f4\u6839\u636e\u4e0d\u540c\u7684\u4e1a\u52a1\u6765\u5b9a\u4e49\uff09<\/li>\n<li>\u5176\u6b21\uff0c<strong>\u5f00\u53d1\u6027\u80fd\u6d4b\u8bd5\u5de5\u5177<\/strong>\uff0c\u4e00\u4e2a\u5de5\u5177\u7528\u6765\u5236\u9020\u9ad8\u5f3a\u5ea6\u7684 Throughput\uff0c\u53e6\u4e00\u4e2a\u5de5\u5177\u7528\u6765\u6d4b\u91cf Latency\u3002\u5bf9\u4e8e\u7b2c\u4e00\u4e2a\u5de5\u5177\uff0c\u4f60\u53ef\u4ee5\u53c2\u8003\u4e00\u4e0b\u201c\u5341\u4e2a\u514d\u8d39\u7684 Web \u538b\u529b\u6d4b\u8bd5\u5de5\u5177\u201d\uff0c\u5173\u4e8e\u5982\u4f55\u6d4b\u91cf Latency\uff0c\u4f60\u53ef\u4ee5\u5728\u4ee3\u7801\u4e2d\u6d4b\u91cf\uff0c\u4f46\u662f\u8fd9\u6837\u4f1a\u5f71\u54cd\u7a0b\u5e8f\u7684\u6267\u884c\uff0c\u800c\u4e14\u53ea\u80fd\u6d4b\u8bd5\u5230\u7a0b\u5e8f\u5185\u90e8\u7684 Latency\uff0c\u771f\u6b63\u7684 Latency \u662f\u6574\u4e2a\u7cfb\u7edf\u90fd\u7b97\u4e0a\uff0c\u5305\u62ec\u64cd\u4f5c\u7cfb\u7edf\u548c\u7f51\u7edc\u7684\u5ef6\u65f6\uff0c\u4f60\u53ef\u4ee5\u4f7f\u7528 Wireshark \u6765\u6293\u7f51\u7edc\u5305\u6765\u6d4b\u91cf\u3002\u8fd9\u4e24\u4e2a\u5de5\u5177\u5177\u4f53\u600e\u4e48\u505a\uff0c\u8fd9\u4e2a\u8fd8\u8bf7\u5927\u5bb6\u81ea\u5df1\u601d\u8003\u53bb\u4e86\u3002<\/li>\n<li>\u6700\u540e\uff0c<strong>\u5f00\u59cb\u6027\u80fd\u6d4b\u8bd5<\/strong>\u3002\u4f60\u9700\u8981\u4e0d\u65ad\u5730\u63d0\u5347\u6d4b\u8bd5\u7684 Throughput\uff0c\u7136\u540e\u89c2\u5bdf\u7cfb\u7edf\u7684\u8d1f\u8f7d\u60c5\u51b5\uff0c\u5982\u679c\u7cfb\u7edf\u9876\u5f97\u4f4f\uff0c\u90a3\u5c31\u89c2\u5bdf Latency \u7684\u503c\u3002\u8fd9\u6837\uff0c\u4f60\u5c31\u53ef\u4ee5\u627e\u5230\u7cfb\u7edf\u7684\u6700\u5927\u8d1f\u8f7d\uff0c\u5e76\u4e14\u4f60\u53ef\u4ee5\u77e5\u9053\u7cfb\u7edf\u7684\u54cd\u5e94\u5ef6\u65f6\u662f\u591a\u5c11\u3002<\/li>\n<\/ul>\n<p>\u518d\u591a\u8bf4\u4e00\u4e9b\uff0c<\/p>\n<ul class=\"list-paddingleft-2\">\n<li>\u5173\u4e8e Latency\uff0c\u5982\u679c\u541e\u5410\u91cf\u5f88\u5c11\uff0c\u8fd9\u4e2a\u503c\u4f30\u8ba1\u4f1a\u975e\u5e38\u7a33\u5b9a\uff0c\u5f53\u541e\u5410\u91cf\u8d8a\u6765\u8d8a\u5927\u65f6\uff0c\u7cfb\u7edf\u7684 Latency \u4f1a\u51fa\u73b0\u975e\u5e38\u5267\u70c8\u7684\u6296\u52a8\uff0c\u6240\u4ee5\uff0c\u6211\u4eec\u5728\u6d4b\u91cf Latency \u7684\u65f6\u5019\uff0c\u6211\u4eec\u9700\u8981\u6ce8\u610f\u5230 Latency \u7684\u5206\u5e03\uff0c\u4e5f\u5c31\u662f\u8bf4\uff0c\u6709\u767e\u5206\u4e4b\u51e0\u7684\u5728\u6211\u4eec\u5141\u8bb8\u7684\u8303\u56f4\uff0c\u6709\u767e\u5206\u4e4b\u51e0\u7684\u8d85\u51fa\u4e86\uff0c\u6709\u767e\u5206\u4e4b\u51e0\u7684\u5b8c\u5168\u4e0d\u53ef\u63a5\u53d7\u3002\u4e5f\u8bb8\uff0c\u5e73\u5747\u4e0b\u6765\u7684 Latency \u8fbe\u6807\u4e86\uff0c\u4f46\u662f\u5176\u4e2d\u4ec5\u6709 50% \u7684\u8fbe\u5230\u4e86\u6211\u4eec\u53ef\u63a5\u53d7\u7684\u8303\u56f4\u3002\u90a3\u4e5f\u6ca1\u6709\u610f\u4e49\u3002<\/li>\n<li>\u5173\u4e8e\u6027\u80fd\u6d4b\u8bd5\uff0c\u6211\u4eec\u8fd8\u9700\u8981\u5b9a\u4e49\u4e00\u4e2a\u65f6\u95f4\u6bb5\u3002\u6bd4\u5982\uff1a\u5728\u67d0\u4e2a\u541e\u5410\u91cf\u4e0a\u6301\u7eed 15 \u5206\u949f\u3002\u56e0\u4e3a\u5f53\u8d1f\u8f7d\u5230\u8fbe\u7684\u65f6\u5019\uff0c\u7cfb\u7edf\u4f1a\u53d8\u5f97\u4e0d\u7a33\u5b9a\uff0c\u5f53\u8fc7\u4e86\u4e00\u4e24\u5206\u949f\u540e\uff0c\u7cfb\u7edf\u624d\u4f1a\u7a33\u5b9a\u3002\u53e6\u5916\uff0c\u4e5f\u6709\u53ef\u80fd\u662f\uff0c\u4f60\u7684\u7cfb\u7edf\u5728\u8fd9\u4e2a\u8d1f\u8f7d\u4e0b\u524d\u51e0\u5206\u949f\u8fd8\u8868\u73b0\u6b63\u5e38\uff0c\u7136\u540e\u5c31\u4e0d\u7a33\u5b9a\u4e86\uff0c\u751a\u81f3\u57ae\u4e86\u3002\u6240\u4ee5\uff0c\u9700\u8981\u8fd9\u4e48\u4e00\u6bb5\u65f6\u95f4\u3002\u8fd9\u4e2a\u503c\uff0c\u6211\u4eec\u53eb\u505a\u5cf0\u503c\u6781\u9650\u3002<\/li>\n<li>\u6027\u80fd\u6d4b\u8bd5\u8fd8\u9700\u8981\u505a Soak Test\uff0c\u4e5f\u5c31\u662f\u5728\u67d0\u4e2a\u541e\u5410\u91cf\u4e0b\uff0c\u7cfb\u7edf\u53ef\u4ee5\u6301\u7eed\u8dd1\u4e00\u5468\u751a\u81f3\u66f4\u957f\u3002\u8fd9\u4e2a\u503c\uff0c\u6211\u4eec\u53eb\u505a\u7cfb\u7edf\u7684\u6b63\u5e38\u8fd0\u884c\u7684\u8d1f\u8f7d\u6781\u9650\u3002<\/li>\n<\/ul>\n<p>\u6027\u80fd\u6d4b\u8bd5\u6709\u5f88\u591a\u5f88\u590d\u8981\u7684\u4e1c\u897f\uff0c\u6bd4\u5982\uff1aburst test \u7b49\u3002 \u8fd9\u91cc\u4e0d\u80fd\u4e00\u4e00\u8be6\u8ff0\uff0c\u8fd9\u91cc\u53ea\u8bf4\u4e86\u4e00\u4e9b\u548c\u6027\u80fd\u8c03\u4f18\u76f8\u5173\u7684\u4e1c\u897f\u3002\u603b\u4e4b\uff0c\u6027\u80fd\u6d4b\u8bd5\u662f\u4e00\u7ec6\u6d3b\u548c\u7d2f\u6d3b\u3002<\/p>\n<h3 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u5b9a\u4f4d\u6027\u80fd\u74f6\u9888\">\u5b9a\u4f4d\u6027\u80fd\u74f6\u9888<\/h3>\n<p>\u6709\u4e86\u4e0a\u9762\u7684\u94fa\u57ab\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u6d4b\u8bd5\u5230\u5230\u7cfb\u7edf\u7684\u6027\u80fd\u4e86\uff0c\u518d\u8c03\u4f18\u4e4b\u524d\uff0c\u6211\u4eec\u5148\u6765\u8bf4\u8bf4\u5982\u4f55\u627e\u5230\u6027\u80fd\u7684\u74f6\u9888\u3002\u6211\u89c1\u8fc7\u5f88\u591a\u670b\u53cb\u4f1a\u89c9\u5f97\u8fd9\u5f88\u5bb9\u6613\uff0c\u4f46\u662f\u4ed4\u7ec6\u4e00\u95ee\uff0c\u5176\u5b9e\u4ed6\u4eec\u5e76\u6ca1\u6709\u4e00\u4e2a\u6bd4\u8f83\u7cfb\u7edf\u7684\u65b9\u6cd5\u3002<\/p>\n<h4 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u67e5\u770b\u64cd\u4f5c\u7cfb\u7edf\u8d1f\u8f7d\">\u67e5\u770b\u64cd\u4f5c\u7cfb\u7edf\u8d1f\u8f7d<\/h4>\n<p>\u9996\u5148\uff0c\u5f53\u6211\u4eec\u7cfb\u7edf\u6709\u95ee\u9898\u7684\u65f6\u5019\uff0c\u6211\u4eec\u4e0d\u8981\u6025\u4e8e\u53bb\u8c03\u67e5\u6211\u4eec\u4ee3\u7801\uff0c\u8fd9\u4e2a\u6beb\u65e0\u610f\u4e49\u3002\u6211\u4eec\u9996\u8981\u9700\u8981\u770b\u7684\u662f\u64cd\u4f5c\u7cfb\u7edf\u7684\u62a5\u544a\u3002\u770b\u770b\u64cd\u4f5c\u7cfb\u7edf\u7684 CPU \u5229\u7528\u7387\uff0c\u770b\u770b\u5185\u5b58\u4f7f\u7528\u7387\uff0c\u770b\u770b\u64cd\u4f5c\u7cfb\u7edf\u7684 IO\uff0c\u8fd8\u6709\u7f51\u7edc\u7684 IO\uff0c\u7f51\u7edc\u94fe\u63a5\u6570\uff0c\u7b49\u7b49\u3002Windows \u4e0b\u7684 perfmon \u662f\u4e00\u4e2a\u5f88\u4e0d\u9519\u7684\u5de5\u5177\uff0cLinux \u4e0b\u4e5f\u6709\u5f88\u591a\u76f8\u5173\u7684\u547d\u4ee4\u548c\u5de5\u5177\uff0c\u6bd4\u5982\uff1aSystemTap\uff0cLatencyTOP\uff0cvmstat, sar, iostat, top, tcpdump \u7b49\u7b49 \u3002\u901a\u8fc7\u89c2\u5bdf\u8fd9\u4e9b\u6570\u636e\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u77e5\u9053\u6211\u4eec\u7684\u8f6f\u4ef6\u7684\u6027\u80fd\u57fa\u672c\u4e0a\u51fa\u5728\u54ea\u91cc\u3002\u6bd4\u5982\uff1a<\/p>\n<p>1\u3001\u5148\u770b CPU \u5229\u7528\u7387\uff0c\u5982\u679c CPU \u5229\u7528\u7387\u4e0d\u9ad8\uff0c\u4f46\u662f\u7cfb\u7edf\u7684 Throughput \u548c Latency \u4e0a\u4e0d\u53bb\u4e86\uff0c\u8fd9\u8bf4\u660e\u6211\u4eec\u7684\u7a0b\u5e8f\u5e76\u6ca1\u6709\u5fd9\u4e8e\u8ba1\u7b97\uff0c\u800c\u662f\u5fd9\u4e8e\u522b\u7684\u4e00\u4e9b\u4e8b\uff0c\u6bd4\u5982 IO\u3002\uff08\u53e6\u5916\uff0cCPU \u7684\u5229\u7528\u7387\u8fd8\u8981\u770b\u5185\u6838\u6001\u7684\u548c\u7528\u6237\u6001\u7684\uff0c\u5185\u6838\u6001\u7684\u4e00\u4e0a\u53bb\u4e86\uff0c\u6574\u4e2a\u7cfb\u7edf\u7684\u6027\u80fd\u5c31\u4e0b\u6765\u4e86\u3002\u800c\u5bf9\u4e8e\u591a\u6838 CPU \u6765\u8bf4\uff0cCPU 0 \u662f\u76f8\u5f53\u5173\u952e\u7684\uff0c\u5982\u679c CPU 0 \u7684\u8d1f\u8f7d\u9ad8\uff0c\u90a3\u4e48\u4f1a\u5f71\u54cd\u5176\u5b83\u6838\u7684\u6027\u80fd\uff0c\u56e0\u4e3a CPU \u5404\u6838\u95f4\u662f\u9700\u8981\u6709\u8c03\u5ea6\u7684\uff0c\u8fd9\u9760 CPU0 \u5b8c\u6210\uff09<\/p>\n<p>2\u3001\u7136\u540e\uff0c\u6211\u4eec\u53ef\u4ee5\u770b\u4e00\u4e0b IO \u5927\u4e0d\u5927\uff0cIO \u548c CPU \u4e00\u822c\u662f\u53cd\u7740\u6765\u7684\uff0cCPU \u5229\u7528\u7387\u9ad8\u5219 IO \u4e0d\u5927\uff0cIO \u5927\u5219 CPU \u5c31\u5c0f\u3002\u5173\u4e8e IO\uff0c\u6211\u4eec\u8981\u770b\u4e09\u4e2a\u4e8b\uff0c\u4e00\u4e2a\u662f\u78c1\u76d8\u6587\u4ef6 IO\uff0c\u4e00\u4e2a\u662f\u9a71\u52a8\u7a0b\u5e8f\u7684 IO\uff08\u5982\uff1a\u7f51\u5361\uff09\uff0c\u4e00\u4e2a\u662f\u5185\u5b58\u6362\u9875\u7387\u3002\u8fd9\u4e09\u4e2a\u4e8b\u90fd\u4f1a\u5f71\u54cd\u7cfb\u7edf\u6027\u80fd\u3002<\/p>\n<p>3\u3001\u7136\u540e\uff0c\u67e5\u770b\u4e00\u4e0b\u7f51\u7edc\u5e26\u5bbd\u4f7f\u7528\u60c5\u51b5\uff0c\u5728 Linux \u4e0b\uff0c\u4f60\u53ef\u4ee5\u4f7f\u7528 iftop, iptraf, ntop, tcpdump \u8fd9\u4e9b\u547d\u4ee4\u6765\u67e5\u770b\u3002\u6216\u662f\u7528 Wireshark \u6765\u67e5\u770b\u3002<\/p>\n<p>4\u3001\u5982\u679c CPU \u4e0d\u9ad8\uff0cIO \u4e0d\u9ad8\uff0c\u5185\u5b58\u4f7f\u7528\u4e0d\u9ad8\uff0c\u7f51\u7edc\u5e26\u5bbd\u4f7f\u7528\u4e0d\u9ad8\u3002\u4f46\u662f\u7cfb\u7edf\u7684\u6027\u80fd\u4e0a\u4e0d\u53bb\u3002\u8fd9\u8bf4\u660e\u4f60\u7684\u7a0b\u5e8f\u6709\u95ee\u9898\uff0c\u6bd4\u5982\uff0c\u4f60\u7684\u7a0b\u5e8f\u88ab\u963b\u585e\u4e86\u3002\u53ef\u80fd\u662f\u56e0\u4e3a\u7b49\u90a3\u4e2a\u9501\uff0c\u53ef\u80fd\u662f\u56e0\u4e3a\u7b49\u67d0\u4e2a\u8d44\u6e90\uff0c\u6216\u8005\u662f\u5728\u5207\u6362\u4e0a\u4e0b\u6587\u3002<\/p>\n<p><strong>\u901a\u8fc7\u4e86\u89e3\u64cd\u4f5c\u7cfb\u7edf\u7684\u6027\u80fd\uff0c\u6211\u4eec\u624d\u77e5\u9053\u6027\u80fd\u7684\u95ee\u9898\uff0c\u6bd4\u5982\uff1a\u5e26\u5bbd\u4e0d\u591f\uff0c\u5185\u5b58\u4e0d\u591f\uff0cTCP \u7f13\u51b2\u533a\u4e0d\u591f\uff0c\u7b49\u7b49\uff0c\u5f88\u591a\u65f6\u5019\uff0c\u4e0d\u9700\u8981\u8c03\u6574\u7a0b\u5e8f\u7684\uff0c\u53ea\u9700\u8981\u8c03\u6574\u4e00\u4e0b\u786c\u4ef6\u6216\u64cd\u4f5c\u7cfb\u7edf\u7684\u914d\u7f6e\u5c31\u53ef\u4ee5\u4e86<\/strong>\u3002<\/p>\n<h4 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u4f7f\u7528Profiler\u6d4b\u8bd5\">\u4f7f\u7528 Profiler \u6d4b\u8bd5<\/h4>\n<p>\u63a5\u4e0b\u6765\uff0c\u6211\u4eec\u9700\u8981\u4f7f\u7528\u6027\u80fd\u68c0\u6d4b\u5de5\u5177\uff0c\u4e5f\u5c31\u662f\u4f7f\u7528\u67d0\u4e2a Profiler \u6765\u5dee\u770b\u4e00\u4e0b\u6211\u4eec\u7a0b\u5e8f\u7684\u8fd0\u884c\u6027\u80fd\u3002\u5982\uff1aJava \u7684 JProfiler\/TPTP\/CodePro Profiler\uff0cGNU \u7684 gprof\uff0cIBM \u7684 PurifyPlus\uff0cIntel \u7684 VTune\uff0cAMD \u7684 CodeAnalyst\uff0c\u8fd8\u6709 Linux \u4e0b\u7684 OProfile\/perf\uff0c\u540e\u9762\u4e24\u4e2a\u53ef\u4ee5\u8ba9\u4f60\u5bf9\u4f60\u7684\u4ee3\u7801\u4f18\u5316\u5230 CPU \u7684\u5fae\u6307\u4ee4\u7ea7\u522b\uff0c\u5982\u679c\u4f60\u5173\u5fc3 CPU \u7684 L1\/L2 \u7684\u7f13\u5b58\u8c03\u4f18\uff0c\u90a3\u4e48\u4f60\u9700\u8981\u8003\u8651\u4e00\u4e0b\u4f7f\u7528 VTune\u3002 \u4f7f\u7528\u8fd9\u4e9b Profiler \u5de5\u5177\uff0c\u53ef\u4ee5\u8ba9\u4f60\u7a0b\u5e8f\u4e2d\u5404\u4e2a\u6a21\u5757\u51fd\u6570\u751a\u81f3\u6307\u4ee4\u7684\u5f88\u591a\u4e1c\u897f\uff0c\u5982\uff1a<strong>\u8fd0\u884c\u7684\u65f6\u95f4 \uff0c\u8c03\u7528\u7684\u6b21\u6570\uff0cCPU \u7684\u5229\u7528\u7387<\/strong>\uff0c\u7b49\u7b49\u3002\u8fd9\u4e9b\u4e1c\u897f\u5bf9\u6211\u4eec\u6765\u8bf4\u975e\u5e38\u6709\u7528\u3002<\/p>\n<p>\u6211\u4eec\u91cd\u70b9\u89c2\u5bdf\u8fd0\u884c\u65f6\u95f4\u6700\u591a\uff0c\u8c03\u7528\u6b21\u6570\u6700\u591a\u7684\u90a3\u4e9b\u51fd\u6570\u548c\u6307\u4ee4\u3002\u8fd9\u91cc\u6ce8\u610f\u4e00\u4e0b\uff0c\u5bf9\u4e8e\u8c03\u7528\u6b21\u6570\u591a\u4f46\u662f\u65f6\u95f4\u5f88\u77ed\u7684\u51fd\u6570\uff0c\u4f60\u53ef\u80fd\u53ea\u9700\u8981\u8f7b\u5fae\u4f18\u5316\u4e00\u4e0b\uff0c\u4f60\u7684\u6027\u80fd\u5c31\u4e0a\u53bb\u4e86\uff08\u6bd4\u5982\uff1a\u67d0\u51fd\u6570\u4e00\u79d2\u79cd\u88ab\u8c03\u7528 100 \u4e07\u6b21\uff0c\u4f60\u60f3\u60f3\u5982\u679c\u4f60\u8ba9\u8fd9\u4e2a\u51fd\u6570\u63d0\u9ad8 0.01 \u6beb\u79d2\u7684\u65f6\u95f4 \uff0c\u8fd9\u4f1a\u7ed9\u4f60\u5e26\u6765\u591a\u5927\u7684\u6027\u80fd\uff09<\/p>\n<p>\u4f7f\u7528 Profiler \u6709\u4e2a\u95ee\u9898\u6211\u4eec\u9700\u8981\u6ce8\u610f\u4e00\u4e0b\uff0c\u56e0\u4e3a Profiler \u4f1a\u8ba9\u4f60\u7684\u7a0b\u5e8f\u8fd0\u884c\u7684\u6027\u80fd\u53d8\u4f4e\uff0c\u50cf PurifyPlus \u8fd9\u6837\u7684\u5de5\u5177\u4f1a\u5728\u4f60\u7684\u4ee3\u7801\u4e2d\u63d2\u5165\u5f88\u591a\u4ee3\u7801\uff0c\u4f1a\u5bfc\u81f4\u4f60\u7684\u7a0b\u5e8f\u8fd0\u884c\u6548\u7387\u53d8\u4f4e\uff0c\u4ece\u800c\u6ca1\u53d1\u6d4b\u8bd5\u51fa\u5728\u9ad8\u541e\u5410\u91cf\u4e0b\u7684\u7cfb\u7edf\u7684\u6027\u80fd\uff0c\u5bf9\u6b64\uff0c\u4e00\u822c\u6709\u4e24\u4e2a\u65b9\u6cd5\u6765\u5b9a\u4f4d\u7cfb\u7edf\u74f6\u9888\uff1a<\/p>\n<p>1\u3001\u5728\u4f60\u7684\u4ee3\u7801\u4e2d\u81ea\u5df1\u505a\u7edf\u8ba1\uff0c\u4f7f\u7528\u5fae\u79d2\u7ea7\u7684\u8ba1\u65f6\u5668\u548c\u51fd\u6570\u8c03\u7528\u8ba1\u7b97\u5668\uff0c\u6bcf\u9694 10 \u79d2\u628a\u7edf\u8ba1 log \u5230\u6587\u4ef6\u4e2d\u3002<\/p>\n<p>2\u3001\u5206\u6bb5\u6ce8\u91ca\u4f60\u7684\u4ee3\u7801\u5757\uff0c\u8ba9\u4e00\u4e9b\u51fd\u6570\u7a7a\u8f6c\uff0c\u505a Hard Code \u7684 Mock\uff0c\u7136\u540e\u518d\u6d4b\u8bd5\u4e00\u4e0b\u7cfb\u7edf\u7684 Throughput \u548c Latency \u662f\u5426\u6709\u8d28\u7684\u53d8\u5316\uff0c\u5982\u679c\u6709\uff0c\u90a3\u4e48\u88ab\u6ce8\u91ca\u7684\u51fd\u6570\u5c31\u662f\u6027\u80fd\u74f6\u9888\uff0c\u518d\u5728\u8fd9\u4e2a\u51fd\u6570\u4f53\u5185\u6ce8\u91ca\u4ee3\u7801\uff0c\u76f4\u5230\u627e\u5230\u6700\u8017\u6027\u80fd\u7684\u8bed\u53e5\u3002<\/p>\n<p>\u6700\u540e\u518d\u8bf4\u4e00\u70b9\uff0c<strong>\u5bf9\u4e8e\u6027\u80fd\u6d4b\u8bd5\uff0c\u4e0d\u540c\u7684 Throughput \u4f1a\u51fa\u73b0\u4e0d\u540c\u7684\u6d4b\u8bd5\u7ed3\u679c\uff0c\u4e0d\u540c\u7684\u6d4b\u8bd5\u6570\u636e\u4e5f\u4f1a\u6709\u4e0d\u540c\u7684\u6d4b\u8bd5\u7ed3\u679c\u3002\u6240\u4ee5\uff0c\u7528\u4e8e\u6027\u80fd\u6d4b\u8bd5\u7684\u6570\u636e\u975e\u5e38\u91cd\u8981\uff0c\u6027\u80fd\u6d4b\u8bd5\u4e2d\uff0c\u6211\u4eec\u9700\u8981\u89c2\u6d4b\u8bd5\u4e0d\u540c Throughput \u7684\u7ed3\u679c<\/strong>\u3002<\/p>\n<h3 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u5e38\u89c1\u7684\u7cfb\u7edf\u74f6\u9888\">\u5e38\u89c1\u7684\u7cfb\u7edf\u74f6\u9888<\/h3>\n<p>\u4e0b\u9762\u8fd9\u4e9b\u4e1c\u897f\u662f\u6211\u6240\u7ecf\u5386\u8fc7\u7684\u4e00\u4e9b\u95ee\u9898\uff0c\u4e5f\u8bb8\u5e76\u4e0d\u5168\uff0c\u4e5f\u8bb8\u5e76\u4e0d\u5bf9\uff0c\u5927\u5bb6\u53ef\u4ee5\u8865\u5145\u6307\u6b63\uff0c\u6211<strong>\u7eaf\u5c5e\u629b\u7816\u5f15\u7389<\/strong>\u3002\u5173\u4e8e\u7cfb\u7edf\u67b6\u6784\u65b9\u9762\u7684\u6027\u80fd\u8c03\u4f18\uff0c\u5927\u5bb6\u53ef\u79fb\u6b65\u770b\u4e00\u4e0b\u300a<a class=\"external-link\" title=\"\u753112306.cn\u8c08\u8c08\u7f51\u7ad9\u6027\u80fd\u6280\u672f\" href=\"http:\/\/coolshell.cn\/articles\/6470.html\" rel=\"nofollow\">\u753112306.cn\u8c08\u8c08\u7f51\u7ad9\u6027\u80fd\u6280\u672f<\/a>\u300b\uff0c\u5173\u4e8eWeb\u65b9\u9762\u7684\u4e00\u4e9b\u6027\u80fd\u8c03\u4f18\u7684\u4e1c\u897f\uff0c\u5927\u5bb6\u53ef\u4ee5\u770b\u770b\u300a<a class=\"external-link\" title=\"Web\u5f00\u53d1\u4e2d\u9700\u8981\u4e86\u89e3\u7684\u4e1c\u897f\" href=\"http:\/\/coolshell.cn\/articles\/6043.html\" rel=\"nofollow\">Web\u5f00\u53d1\u4e2d\u9700\u8981\u4e86\u89e3\u7684\u4e1c\u897f<\/a>\u300b\u4e00\u6587\u4e2d\u7684\u6027\u80fd\u4e00\u7ae0\u3002\u6211\u5728\u8fd9\u91cc\u5c31\u4e0d\u518d\u8bf4\u8bbe\u8ba1\u548c\u67b6\u6784\u4e0a\u7684\u4e1c\u897f\u4e86\u3002<\/p>\n<p>\u4e00\u822c\u6765\u8bf4\uff0c\u6027\u80fd\u4f18\u5316\u4e5f\u5c31\u662f\u4e0b\u9762\u7684\u51e0\u4e2a\u7b56\u7565\uff1a<\/p>\n<ul class=\"list-paddingleft-2\">\n<li><strong>\u7528\u7a7a\u95f4\u6362\u65f6\u95f4<\/strong>\u3002\u5404\u79cd cache \u5982 CPU L1\/L2\/RAM \u5230\u786c\u76d8\uff0c\u90fd\u662f\u7528\u7a7a\u95f4\u6765\u6362\u65f6\u95f4\u7684\u7b56\u7565\u3002\u8fd9\u6837\u7b56\u7565\u57fa\u672c\u4e0a\u662f\u628a\u8ba1\u7b97\u7684\u8fc7\u7a0b\u4e00\u6b65\u4e00\u6b65\u7684\u4fdd\u5b58\u6216\u7f13\u5b58\u4e0b\u6765\uff0c\u8fd9\u6837\u5c31\u4e0d\u7528\u6bcf\u6b21\u7528\u7684\u65f6\u5019\u90fd\u8981\u518d\u8ba1\u7b97\u4e00\u904d\uff0c\u6bd4\u5982\u6570\u636e\u7f13\u51b2\uff0cCDN\uff0c\u7b49\u3002\u8fd9\u6837\u7684\u7b56\u7565\u8fd8\u8868\u73b0\u4e3a\u5197\u4f59\u6570\u636e\uff0c\u6bd4\u5982\u6570\u636e\u955c\u8c61\uff0c\u8d1f\u8f7d\u5747\u8861\u4ec0\u4e48\u7684\u3002<\/li>\n<li><strong>\u7528\u65f6\u95f4\u6362\u7a7a\u95f4<\/strong>\u3002\u6709\u65f6\u5019\uff0c\u5c11\u91cf\u7684\u7a7a\u95f4\u53ef\u80fd\u6027\u80fd\u4f1a\u66f4\u597d\uff0c\u6bd4\u5982\u7f51\u7edc\u4f20\u8f93\uff0c\u5982\u679c\u6709\u4e00\u4e9b\u538b\u7f29\u6570\u636e\u7684\u7b97\u6cd5\uff08\u5982\u524d\u4e9b\u5929\u8bf4\u7684\u201cHuffman \u7f16\u7801\u538b\u7f29\u7b97\u6cd5\u201d \u548c \u201crsync \u7684\u6838\u5fc3\u7b97\u6cd5\u201d\uff09\uff0c\u8fd9\u6837\u7684\u7b97\u6cd5\u5176\u5b9e\u5f88\u8017\u65f6\uff0c\u4f46\u662f\u56e0\u4e3a\u74f6\u9888\u5728\u7f51\u7edc\u4f20\u8f93\uff0c\u6240\u4ee5\u7528\u65f6\u95f4\u6765\u6362\u7a7a\u95f4\u53cd\u800c\u80fd\u7701\u65f6\u95f4\u3002<\/li>\n<li><strong>\u7b80\u5316\u4ee3\u7801<\/strong>\u3002\u6700\u9ad8\u6548\u7684\u7a0b\u5e8f\u5c31\u662f\u4e0d\u6267\u884c\u4efb\u4f55\u4ee3\u7801\u7684\u7a0b\u5e8f\uff0c\u6240\u4ee5\uff0c\u4ee3\u7801\u8d8a\u5c11\u6027\u80fd\u5c31\u8d8a\u9ad8\u3002\u5173\u4e8e\u4ee3\u7801\u7ea7\u4f18\u5316\u7684\u6280\u672f\u5927\u5b66\u91cc\u7684\u6559\u79d1\u4e66\u6709\u5f88\u591a\u793a\u4f8b\u4e86\u3002\u5982\uff1a\u51cf\u5c11\u5faa\u73af\u7684\u5c42\u6570\uff0c\u51cf\u5c11\u9012\u5f52\uff0c\u5728\u5faa\u73af\u4e2d\u5c11\u58f0\u660e\u53d8\u91cf\uff0c\u5c11\u505a\u5206\u914d\u548c\u91ca\u653e\u5185\u5b58\u7684\u64cd\u4f5c\uff0c\u5c3d\u91cf\u628a\u5faa\u73af\u4f53\u5185\u7684\u8868\u8fbe\u5f0f\u62bd\u5230\u5faa\u73af\u5916\uff0c\u6761\u4ef6\u8868\u8fbe\u7684\u4e2d\u7684\u591a\u4e2a\u6761\u4ef6\u5224\u65ad\u7684\u6b21\u5e8f\uff0c\u5c3d\u91cf\u5728\u7a0b\u5e8f\u542f\u52a8\u65f6\u628a\u4e00\u4e9b\u4e1c\u897f\u51c6\u5907\u597d\uff0c\u6ce8\u610f\u51fd\u6570\u8c03\u7528\u7684\u5f00\u9500\uff08\u6808\u4e0a\u5f00\u9500\uff09\uff0c\u6ce8\u610f\u9762\u5411\u5bf9\u8c61\u8bed\u8a00\u4e2d\u4e34\u65f6\u5bf9\u8c61\u7684\u5f00\u9500\uff0c\u5c0f\u5fc3\u4f7f\u7528\u5f02\u5e38\uff08\u4e0d\u8981\u7528\u5f02\u5e38\u6765\u68c0\u67e5\u4e00\u4e9b\u53ef\u63a5\u53d7\u53ef\u5ffd\u7565\u5e76\u7ecf\u5e38\u53d1\u751f\u7684\u9519\u8bef\uff09\uff0c\u2026\u2026 \u7b49\u7b49\uff0c\u7b49\u7b49\uff0c\u8fd9\u8fde\u4e1c\u897f\u9700\u8981\u6211\u4eec\u975e\u5e38\u4e86\u89e3\u7f16\u7a0b\u8bed\u8a00\u548c\u5e38\u7528\u7684\u5e93\u3002<\/li>\n<li><strong>\u5e76\u884c\u5904\u7406<\/strong>\u3002\u5982\u679c CPU \u53ea\u6709\u4e00\u4e2a\u6838\uff0c\u4f60\u8981\u73a9\u591a\u8fdb\u7a0b\uff0c\u591a\u7ebf\u7a0b\uff0c\u5bf9\u4e8e\u8ba1\u7b97\u5bc6\u96c6\u578b\u7684\u8f6f\u4ef6\u4f1a\u53cd\u800c\u66f4\u6162\uff08\u56e0\u4e3a\u64cd\u4f5c\u7cfb\u7edf\u8c03\u5ea6\u548c\u5207\u6362\u5f00\u9500\u5f88\u5927\uff09\uff0cCPU \u7684\u6838\u591a\u4e86\u624d\u80fd\u771f\u6b63\u4f53\u73b0\u51fa\u591a\u8fdb\u7a0b\u591a\u7ebf\u7a0b\u7684\u4f18\u52bf\u3002\u5e76\u884c\u5904\u7406\u9700\u8981\u6211\u4eec\u7684\u7a0b\u5e8f\u6709 Scalability\uff0c\u4e0d\u80fd\u6c34\u5e73\u6216\u5782\u76f4\u6269\u5c55\u7684\u7a0b\u5e8f\u65e0\u6cd5\u8fdb\u884c\u5e76\u884c\u5904\u7406\u3002\u4ece\u67b6\u6784\u4e0a\u6765\u8bf4\uff0c\u8fd9\u8868\u518d\u4e3a\u2014\u2014\u662f\u5426\u53ef\u4ee5\u505a\u5230\u4e0d\u6539\u4ee3\u7801\u53ea\u662f\u52a0\u52a0\u673a\u5668\u5c31\u53ef\u4ee5\u5b8c\u6210\u6027\u80fd\u63d0\u5347\uff1f<\/li>\n<\/ul>\n<p>\u603b\u4e4b\uff0c<strong>\u6839\u636e 2\uff1a8 \u539f\u5219\u6765\u8bf4\uff0c20% \u7684\u4ee3\u7801\u8017\u4e86\u4f60 80% \u7684\u6027\u80fd\uff0c\u627e\u5230\u90a3 20% \u7684\u4ee3\u7801\uff0c\u4f60\u5c31\u53ef\u4ee5\u4f18\u5316\u90a3 80% \u7684\u6027\u80fd<\/strong>\u3002\u4e0b\u9762\u7684\u4e00\u4e9b\u4e1c\u897f\u90fd\u662f\u6211\u7684\u4e00\u4e9b\u7ecf\u9a8c\uff0c\u6211\u53ea\u4f8b\u4e3e\u4e86\u4e00\u4e9b\u6700\u6709\u4ef7\u503c\u7684\u6027\u80fd\u8c03\u4f18\u7684\u7684\u65b9\u6cd5\uff0c\u4f9b\u4f60\u53c2\u8003\uff0c\u4e5f\u6b22\u8fce\u8865\u5145\u3002<\/p>\n<h4 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u7b97\u6cd5\u8c03\u4f18\">\u7b97\u6cd5\u8c03\u4f18<\/h4>\n<p>\u7b97\u6cd5\u975e\u5e38\u91cd\u8981\uff0c\u597d\u7684\u7b97\u6cd5\u4f1a\u6709\u66f4\u597d\u7684\u6027\u80fd\u3002\u4e3e\u51e0\u4e2a\u6211\u7ecf\u5386\u8fc7\u7684\u9879\u76ee\u7684\u4f8b\u5b50\uff0c\u5927\u5bb6\u53ef\u4ee5\u611f\u89c9\u4e00\u4e0b\u3002<\/p>\n<ul class=\"list-paddingleft-2\">\n<li>\u4e00\u4e2a\u662f <strong>\u8fc7\u6ee4\u7b97\u6cd5<\/strong>\uff0c\u7cfb\u7edf\u9700\u8981\u5bf9\u6536\u5230\u7684\u8bf7\u6c42\u505a\u8fc7\u6ee4\uff0c\u6211\u4eec\u628a\u53ef\u4ee5\u88ab filter in\/out \u7684\u4e1c\u897f\u914d\u7f6e\u5728\u4e86\u4e00\u4e2a\u6587\u4ef6\u4e2d\uff0c\u539f\u6709\u7684\u8fc7\u6ee4\u7b97\u6cd5\u662f\u904d\u5386\u8fc7\u6ee4\u914d\u7f6e\uff0c\u540e\u6765\uff0c\u6211\u4eec\u627e\u5230\u4e86\u4e00\u79cd\u65b9\u6cd5\u53ef\u4ee5\u5bf9\u8fd9\u4e2a\u8fc7\u6ee4\u914d\u7f6e\u8fdb\u884c\u6392\u5e8f\uff0c\u8fd9\u6837\u5c31\u53ef\u4ee5\u7528\u4e8c\u5206\u6298\u534a\u7684\u65b9\u6cd5\u6765\u8fc7\u6ee4\uff0c\u7cfb\u7edf\u6027\u80fd\u589e\u52a0\u4e86 50%\u3002<\/li>\n<li>\u4e00\u4e2a\u662f <strong>\u54c8\u5e0c\u7b97\u6cd5<\/strong>\u3002\u8ba1\u7b97\u54c8\u5e0c\u7b97\u6cd5\u7684\u51fd\u6570\u5e76\u4e0d\u9ad8\u6548\uff0c\u4e00\u65b9\u9762\u662f\u8ba1\u7b97\u592a\u8d39\u65f6\uff0c\u53e6\u4e00\u65b9\u9762\u662f\u78b0\u649e\u592a\u9ad8\uff0c\u78b0\u649e\u9ad8\u4e86\u5c31\u8ddf\u5355\u5411\u94fe\u8868\u4e00\u4e2a\u6027\u80fd\uff08\u53ef\u53c2\u770b Hash Collision DoS \u95ee\u9898\uff09\u3002\u6211\u4eec\u77e5\u9053\uff0c\u7b97\u6cd5\u90fd\u662f\u548c\u9700\u8981\u5904\u7406\u7684\u6570\u636e\u5f88\u6709\u5173\u7cfb\u7684\uff0c\u5c31\u7b97\u662f\u88ab\u5927\u5bb6\u6240\u5632\u7b11\u7684\u201c\u5192\u6ce1\u6392\u5e8f\u201d\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\uff08\u5927\u591a\u6570\u6570\u636e\u662f\u6392\u597d\u5e8f\u7684\uff09\u5176\u6548\u7387\u4f1a\u9ad8\u4e8e\u6240\u6709\u7684\u6392\u5e8f\u7b97\u6cd5\u3002\u54c8\u5e0c\u7b97\u6cd5\u4e5f\u4e00\u6837\uff0c\u5e7f\u4e3a\u4eba\u77e5\u7684\u54c8\u5e0c\u7b97\u6cd5\u90fd\u662f\u7528\u82f1\u6587\u5b57\u5178\u505a\u6d4b\u8bd5\uff0c\u4f46\u662f\u6211\u4eec\u7684\u4e1a\u52a1\u5728\u6570\u636e\u6709\u5176\u7279\u6b8a\u6027\uff0c\u6240\u4ee5\uff0c\u5bf9\u4e8e\u8fd8\u9700\u8981\u6839\u636e\u81ea\u5df1\u7684\u6570\u636e\u6765\u6311\u9009\u9002\u5408\u7684\u54c8\u5e0c\u7b97\u6cd5\u3002\u5bf9\u4e8e\u6211\u4ee5\u524d\u7684\u4e00\u4e2a\u9879\u76ee\uff0c\u516c\u53f8\u5185\u67d0\u725b\u4eba\u7ed9\u6211\u53d1\u6765\u4e86\u4e00\u4e2a\u54c8\u5e0c\u7b97\u6cd5\uff0c\u7ed3\u679c\u8ba9\u6211\u4eec\u7684\u7cfb\u7edf\u6027\u80fd\u4e0a\u5347\u4e86 150%\u3002\uff08\u5173\u4e8e\u5404\u79cd\u54c8\u5e0c\u7b97\u6cd5\uff0c\u4f60\u4e00\u5b9a\u8981\u770b\u770b StackExchange \u4e0a\u7684\u8fd9\u7bc7\u5173\u4e8e\u5404\u79cd hash \u7b97\u6cd5\u7684\u6587\u7ae0 \uff09<\/li>\n<li><strong>\u5206\u800c\u6cbb\u4e4b\u548c\u9884\u5904\u7406<\/strong>\u3002\u4ee5\u524d\u6709\u4e00\u4e2a\u7a0b\u5e8f\u4e3a\u4e86\u751f\u6210\u6708\u62a5\u8868\uff0c\u6bcf\u6b21\u90fd\u9700\u8981\u8ba1\u7b97\u5f88\u957f\u7684\u65f6\u95f4\uff0c\u6709\u65f6\u5019\u9700\u8981\u82b1\u5c06\u8fd1\u4e00\u6574\u5929\u7684\u65f6\u95f4\u3002\u4e8e\u662f\u6211\u4eec\u628a\u6211\u4eec\u627e\u5230\u4e86\u4e00\u79cd\u65b9\u6cd5\u53ef\u4ee5\u628a\u8fd9\u4e2a\u7b97\u6cd5\u53d1\u6210\u589e\u91cf\u5f0f\u7684\uff0c\u4e5f\u5c31\u662f\u8bf4\u6211\u6bcf\u5929\u90fd\u628a\u5f53\u5929\u7684\u6570\u636e\u8ba1\u7b97\u597d\u4e86\u540e\u548c\u524d\u4e00\u5929\u7684\u62a5\u8868\u5408\u5e76\uff0c\u8fd9\u6837\u53ef\u4ee5\u5927\u5927\u7684\u8282\u7701\u8ba1\u7b97\u65f6\u95f4\uff0c\u6bcf\u5929\u7684\u6570\u636e\u8ba1\u7b97\u91cf\u53ea\u9700\u8981 20 \u5206\u949f\uff0c\u4f46\u662f\u5982\u679c\u6211\u8981\u7b97\u6574\u4e2a\u6708\u7684\uff0c\u7cfb\u7edf\u5219\u9700\u8981 10 \u4e2a\u5c0f\u65f6\u4ee5\u4e0a\uff08SQL \u8bed\u53e5\u5728\u5927\u6570\u636e\u91cf\u9762\u524d\u6027\u80fd\u6210\u7ea7\u6570\u6027\u4e0b\u964d\uff09\u3002\u8fd9\u79cd\u5206\u800c\u6cbb\u4e4b\u7684\u601d\u8def\u5728\u5927\u6570\u636e\u9762\u524d\u5bf9\u6027\u80fd\u6709\u5f88\u5e2e\u52a9\uff0c\u5c31\u50cf merge \u6392\u5e8f\u4e00\u6837\u3002SQL \u8bed\u53e5\u548c\u6570\u636e\u5e93\u7684\u6027\u80fd\u4f18\u5316\u4e5f\u662f\u8fd9\u4e00\u7b56\u7565\uff0c\u5982\uff1a\u4f7f\u7528\u5d4c\u5957\u5f0f\u7684 Select \u800c\u4e0d\u662f\u7b1b\u5361\u5c14\u79ef\u7684 Select\uff0c\u4f7f\u7528\u89c6\u56fe\uff0c\u7b49\u7b49\u3002<\/li>\n<\/ul>\n<h4 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u4ee3\u7801\u8c03\u4f18\">\u4ee3\u7801\u8c03\u4f18<\/h4>\n<p>\u4ece\u6211\u7684\u7ecf\u9a8c\u4e0a\u6765\u8bf4\uff0c\u4ee3\u7801\u4e0a\u7684\u8c03\u4f18\u6709\u4e0b\u9762\u8fd9\u51e0\u70b9\uff1a<\/p>\n<p><strong>\u5b57\u7b26\u4e32\u64cd\u4f5c<\/strong>\u3002\u8fd9\u662f\u6700\u8d39\u7cfb\u7edf\u6027\u80fd\u7684\u4e8b\u4e86\uff0c\u65e0\u8bba\u662f strcpy, strcat \u8fd8\u662f strlen\uff0c\u6700\u9700\u8981\u6ce8\u610f\u7684\u662f\u5b57\u7b26\u4e32\u5b50\u4e32\u5339\u914d\u3002\u6240\u4ee5\uff0c\u80fd\u7528\u6574\u578b\u6700\u597d\u7528\u6574\u578b\u3002\u4e3e\u51e0\u4e2a\u4f8b\u5b50\uff0c\u7b2c\u4e00\u4e2a\u4f8b\u5b50\u662f N \u5e74\u524d\u505a\u94f6\u884c\u7684\u65f6\u5019\uff0c\u6211\u7684\u540c\u4e8b\u559c\u6b22\u628a\u65e5\u671f\u5b58\u6210\u5b57\u7b26\u4e32\uff08\u5982\uff1a2012-05-29 08:30:02\uff09\uff0c\u6211\u52d2\u4e2a\u53bb\uff0c\u4e00\u4e2a select \u00a0where between \u8bed\u53e5\u76f8\u5f53\u8017\u65f6\u3002<\/p>\n<p>\u53e6\u4e00\u4e2a\u4f8b\u5b50\u662f\uff0c\u6211\u4ee5\u524d\u6709\u4e2a\u540c\u4e8b\u628a\u4e00\u4e9b\u72b6\u6001\u7801\u7528\u5b57\u7b26\u4e32\u6765\u5904\u7406\uff0c\u4ed6\u7684\u7406\u7531\u662f\uff0c\u8fd9\u6837\u53ef\u4ee5\u5728\u754c\u9762\u4e0a\u76f4\u63a5\u663e\u793a\uff0c\u540e\u6765\u6027\u80fd\u8c03\u4f18\u7684\u65f6\u5019\uff0c\u6211\u628a\u8fd9\u4e9b\u72b6\u6001\u7801\u5168\u6539\u6210\u6574\u578b\uff0c\u7136\u540e\u7528\u4f4d\u64cd\u4f5c\u67e5\u72b6\u6001\uff0c\u56e0\u4e3a\u6709\u4e00\u4e2a\u6bcf\u79d2\u949f\u88ab\u8c03\u7528\u4e86 150K \u6b21\u7684\u51fd\u6570\u91cc\u9762\u6709\u4e09\u5904\u9700\u8981\u68c0\u67e5\u72b6\u6001\uff0c\u7ecf\u8fc7\u6539\u5584\u4ee5\u540e\uff0c\u6574\u4e2a\u7cfb\u7edf\u7684\u6027\u80fd\u4e0a\u5347\u4e86 30% \u5de6\u53f3\u3002\u8fd8\u6709\u4e00\u4e2a\u4f8b\u5b50\u662f\uff0c\u6211\u4ee5\u524d\u4ece\u4e8b\u7684\u67d0\u4e2a\u4ea7\u54c1\u7f16\u7a0b\u89c4\u8303\u4e2d\u6709\u4e00\u6761\u662f\u8981\u5728\u6bcf\u4e2a\u51fd\u6570\u4e2d\u628a\u51fd\u6570\u540d\u5b9a\u4e49\u51fa\u6765\uff0c\u5982\uff1aconst char fname[]=\u201dfunctionName()\u201d, \u8fd9\u662f\u4e3a\u4e86\u597d\u6253\u65e5\u5fd7\uff0c\u4f46\u662f\u4e3a\u4ec0\u4e48\u4e0d\u58f0\u660e\u6210 static \u7c7b\u578b\u7684\u5462\uff1f<\/p>\n<p><strong>\u591a\u7ebf\u7a0b\u8c03\u4f18<\/strong>\u3002\u6709\u4eba\u8bf4\uff0cthread is evil\uff0c\u8fd9\u4e2a\u5bf9\u4e8e\u7cfb\u7edf\u6027\u80fd\u5728\u67d0\u4e9b\u65f6\u5019\u662f\u4e2a\u95ee\u9898\u3002\u56e0\u4e3a\u591a\u7ebf\u7a0b\u74f6\u9888\u5c31\u5728\u4e8e\u4e92\u65a5\u548c\u540c\u6b65\u7684\u9501\u4e0a\uff0c\u4ee5\u53ca\u7ebf\u7a0b\u4e0a\u4e0b\u6587\u5207\u6362\u7684\u6210\u672c\uff0c\u600e\u4e48\u6837\u7684\u5c11\u7528\u9501\u6216\u4e0d\u7528\u9501\u662f\u6839\u672c\uff08\u6bd4\u5982\uff1a\u591a\u7248\u672c\u5e76\u53d1\u63a7\u5236 (MVCC) \u5728\u5206\u5e03\u5f0f\u7cfb\u7edf\u4e2d\u7684\u5e94\u7528 \u4e2d\u8bf4\u7684\u4e50\u89c2\u9501\u53ef\u4ee5\u89e3\u51b3\u6027\u80fd\u95ee\u9898\uff09\uff0c\u6b64\u5916\uff0c\u8fd8\u6709\u8bfb\u5199\u9501\u4e5f\u53ef\u4ee5\u89e3\u51b3\u5927\u591a\u6570\u662f\u8bfb\u64cd\u4f5c\u7684\u5e76\u53d1\u7684\u6027\u80fd\u95ee\u9898\u3002<\/p>\n<p>\u8fd9\u91cc\u591a\u8bf4\u4e00\u70b9\u5728 C++ \u4e2d\uff0c\u6211\u4eec\u53ef\u80fd\u4f1a\u4f7f\u7528\u7ebf\u7a0b\u5b89\u5168\u7684\u667a\u80fd\u6307\u9488 AutoPtr \u6216\u662f\u522b\u7684\u4e00\u4e9b\u5bb9\u5668\uff0c\u53ea\u8981\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u5176\u4e0d\u7ba1\u4e09\u4e03\u4e8c\u5341\u4e00\u90fd\u8981\u4e0a\u9501\uff0c\u4e0a\u9501\u662f\u4e2a\u6210\u672c\u5f88\u9ad8\u7684\u64cd\u4f5c\uff0c\u4f7f\u7528 AutoPtr \u4f1a\u8ba9\u6211\u4eec\u7684\u7cfb\u7edf\u6027\u80fd\u4e0b\u964d\u5f97\u5f88\u5feb\uff0c\u5982\u679c\u4f60\u53ef\u4ee5\u4fdd\u8bc1\u4e0d\u4f1a\u6709\u7ebf\u7a0b\u5e76\u53d1\u95ee\u9898\uff0c\u90a3\u4e48\u4f60\u5e94\u8be5\u4e0d\u8981\u7528 AutoPtr\u3002\u6211\u8bb0\u5f97\u6211\u4e0a\u6b21\u6211\u4eec\u540c\u4e8b\u53bb\u6389\u667a\u80fd\u6307\u9488\u7684\u5f15\u7528\u8ba1\u6570\uff0c\u8ba9\u7cfb\u7edf\u6027\u80fd\u63d0\u5347\u4e86 50% \u4ee5\u4e0a\u3002\u5bf9\u4e8e Java \u5bf9\u8c61\u7684\u5f15\u7528\u8ba1\u6570\uff0c\u5982\u679c\u6211\u731c\u7684\u6ca1\u9519\u7684\u8bdd\uff0c\u5230\u5904\u90fd\u662f\u9501\uff0c\u6240\u4ee5\uff0cJava \u7684\u6027\u80fd\u95ee\u9898\u4e00\u76f4\u662f\u4e2a\u95ee\u9898\u3002\u53e6\u5916\uff0c\u7ebf\u7a0b\u4e0d\u662f\u8d8a\u591a\u8d8a\u597d\uff0c\u7ebf\u7a0b\u95f4\u7684\u8c03\u5ea6\u548c\u4e0a\u4e0b\u6587\u5207\u6362\u4e5f\u662f\u5f88\u5938\u5f20\u7684\u4e8b\uff0c\u5c3d\u53ef\u80fd\u7684\u5728\u4e00\u4e2a\u7ebf\u7a0b\u91cc\u5e72\uff0c\u5c3d\u53ef\u80fd\u7684\u4e0d\u8981\u540c\u6b65\u7ebf\u7a0b\u3002\u8fd9\u4f1a\u8ba9\u4f60\u6709\u5f88\u591a\u7684\u6027\u80fd\u3002<\/p>\n<p><strong>\u5185\u5b58\u5206\u914d<\/strong>\u3002\u4e0d\u8981\u5c0f\u770b\u7a0b\u5e8f\u7684\u5185\u5b58\u5206\u914d\u3002malloc\/realloc\/calloc \u8fd9\u6837\u7684\u7cfb\u7edf\u8c03\u975e\u5e38\u8017\u65f6\uff0c\u5c24\u5176\u662f\u5f53\u5185\u5b58\u51fa\u73b0\u788e\u7247\u7684\u65f6\u5019\u3002\u6211\u4ee5\u524d\u7684\u516c\u53f8\u51fa\u8fc7\u8fd9\u6837\u4e00\u4e2a\u95ee\u9898\u2014\u2014\u5728\u7528\u6237\u7684\u7ad9\u70b9\u4e0a\uff0c\u6211\u4eec\u7684\u7a0b\u5e8f\u6709\u4e00\u5929\u4e0d\u54cd\u5e94\u4e86\uff0c\u7528 GDB \u8ddf\u8fdb\u53bb\u4e00\u770b\uff0c\u7cfb\u7edf hang \u5728\u4e86 malloc \u64cd\u4f5c\u4e0a\uff0c20 \u79d2\u90fd\u6ca1\u6709\u8fd4\u56de\uff0c\u91cd\u542f\u4e00\u4e9b\u7cfb\u7edf\u5c31\u597d\u4e86\u3002\u8fd9\u5c31\u662f\u5185\u5b58\u788e\u7247\u7684\u95ee\u9898\u3002\u8fd9\u5c31\u662f\u4e3a\u4ec0\u4e48\u5f88\u591a\u4eba\u62b1\u6028 STL \u6709\u4e25\u91cd\u7684\u5185\u5b58\u788e\u7247\u7684\u95ee\u9898\uff0c\u56e0\u4e3a\u592a\u591a\u7684\u5c0f\u5185\u5b58\u7684\u5206\u914d\u91ca\u653e\u4e86\u3002\u6709\u5f88\u591a\u4eba\u4f1a\u4ee5\u4e3a\u7528\u5185\u5b58\u6c60\u53ef\u4ee5\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c\u4f46\u662f\u5b9e\u9645\u4e0a\u4ed6\u4eec\u53ea\u662f\u91cd\u65b0\u53d1\u660e\u4e86 Runtime-C \u6216\u64cd\u4f5c\u7cfb\u7edf\u7684\u5185\u5b58\u7ba1\u7406\u673a\u5236\uff0c\u5b8c\u5168\u4e8e\u4e8b\u65e0\u8865\u3002<\/p>\n<p>\u5f53\u7136\u89e3\u51b3\u5185\u5b58\u788e\u7247\u7684\u95ee\u9898\u8fd8\u662f\u901a\u8fc7\u5185\u5b58\u6c60\uff0c\u5177\u4f53\u6765\u8bf4\u662f\u4e00\u7cfb\u5217\u4e0d\u540c\u5c3a\u5bf8\u7684\u5185\u5b58\u6c60\uff08\u8fd9\u4e2a\u7559\u7ed9\u5927\u5bb6\u81ea\u5df1\u53bb\u601d\u8003\uff09\u3002\u5f53\u7136\uff0c\u5c11\u8fdb\u884c\u52a8\u6001\u5185\u5b58\u5206\u914d\u662f\u6700\u597d\u7684\u3002\u8bf4\u5230\u5185\u5b58\u6c60\u5c31\u9700\u8981\u8bf4\u4e00\u4e0b\u6c60\u5316\u6280\u672f\u3002\u6bd4\u5982\u7ebf\u7a0b\u6c60\uff0c\u8fde\u63a5\u6c60\u7b49\u3002\u6c60\u5316\u6280\u672f\u5bf9\u4e8e\u4e00\u4e9b\u77ed\u4f5c\u4e1a\u6765\u8bf4\uff08\u5982 http \u670d\u52a1\uff09 \u76f8\u5f53\u76f8\u5f53\u7684\u6709\u6548\u3002\u8fd9\u9879\u6280\u672f\u53ef\u4ee5\u51cf\u5c11\u94fe\u63a5\u5efa\u7acb\uff0c\u7ebf\u7a0b\u521b\u5efa\u7684\u5f00\u9500\uff0c\u4ece\u800c\u63d0\u9ad8\u6027\u80fd\u3002<\/p>\n<p><strong>\u5f02\u6b65\u64cd\u4f5c<\/strong>\u3002\u6211\u4eec\u77e5\u9053 Unix \u4e0b\u7684\u6587\u4ef6\u64cd\u4f5c\u662f\u6709 block \u548c non-block \u7684\u65b9\u5f0f\u7684\uff0c\u50cf\u6709\u4e9b\u7cfb\u7edf\u8c03\u7528\u4e5f\u662f block \u5f0f\u7684\uff0c\u5982\uff1aSocket \u4e0b\u7684 select\uff0cWindows \u4e0b\u7684 WaitforObject \u4e4b\u7c7b\u7684\uff0c\u5982\u679c\u6211\u4eec\u7684\u7a0b\u5e8f\u662f\u540c\u6b65\u64cd\u4f5c\uff0c\u90a3\u4e48\u4f1a\u975e\u5e38\u5f71\u54cd\u6027\u80fd\uff0c\u6211\u4eec\u53ef\u4ee5\u6539\u6210\u5f02\u6b65\u7684\uff0c\u4f46\u662f\u6539\u6210\u5f02\u6b65\u7684\u65b9\u5f0f\u4f1a\u8ba9\u4f60\u7684\u7a0b\u5e8f\u53d8\u590d\u6742\u3002\u5f02\u6b65\u65b9\u5f0f\u4e00\u822c\u8981\u901a\u8fc7\u961f\u5217\uff0c\u8981\u6ce8\u95f4\u961f\u5217\u7684\u6027\u80fd\u95ee\u9898\uff0c\u53e6\u5916\uff0c\u5f02\u6b65\u4e0b\u7684\u72b6\u6001\u901a\u77e5\u901a\u5e38\u662f\u4e2a\u95ee\u9898\uff0c\u6bd4\u5982\u6d88\u606f\u4e8b\u4ef6\u901a\u77e5\u65b9\u5f0f\uff0c\u6709 callback \u65b9\u5f0f\uff0c\u7b49\uff0c\u8fd9\u4e9b\u65b9\u5f0f\u540c\u6837\u53ef\u80fd\u4f1a\u5f71\u54cd\u4f60\u7684\u6027\u80fd\u3002\u4f46\u662f\u901a\u5e38\u6765\u8bf4\uff0c\u5f02\u6b65\u64cd\u4f5c\u4f1a\u8ba9\u6027\u80fd\u7684\u541e\u5410\u7387\u6709\u5f88\u5927\u63d0\u5347\uff08Throughput\uff09\uff0c\u4f46\u662f\u4f1a\u727a\u7272\u7cfb\u7edf\u7684\u54cd\u5e94\u65f6\u95f4\uff08latency\uff09\u3002\u8fd9\u9700\u8981\u4e1a\u52a1\u4e0a\u652f\u6301\u3002<\/p>\n<p><strong>\u8bed\u8a00\u548c\u4ee3\u7801\u5e93<\/strong>\u3002\u6211\u4eec\u8981\u719f\u6089\u8bed\u8a00\u4ee5\u53ca\u6240\u4f7f\u7528\u7684\u51fd\u6570\u5e93\u6216\u7c7b\u5e93\u7684\u6027\u80fd\u3002\u6bd4\u5982\uff1aSTL \u4e2d\u7684\u5f88\u591a\u5bb9\u5668\u5206\u914d\u4e86\u5185\u5b58\u540e\uff0c\u90a3\u6015\u4f60\u5220\u9664\u5143\u7d20\uff0c\u5185\u5b58\u4e5f\u4e0d\u4f1a\u56de\u6536\uff0c\u5176\u4f1a\u9020\u6210\u5185\u5b58\u6cc4\u9732\u7684\u5047\u50cf\uff0c\u5e76\u53ef\u80fd\u9020\u6210\u5185\u5b58\u788e\u7247\u95ee\u9898\u3002\u518d\u5982\uff0cSTL \u67d0\u4e9b\u5bb9\u5668\u7684 size()==0 \u00a0\u548c empty() \u662f\u4e0d\u4e00\u6837\u7684\uff0c\u56e0\u4e3a\uff0csize() \u662f O(n) \u590d\u6742\u5ea6\uff0cempty() \u662f O(1) \u7684\u590d\u6742\u5ea6\uff0c\u8fd9\u4e2a\u8981\u5c0f\u5fc3\u3002Java \u4e2d\u7684 JVM \u8c03\u4f18\u9700\u8981\u4f7f\u7528\u7684\u8fd9\u4e9b\u53c2\u6570\uff1a-Xms -Xmx -Xmn -XX:SurvivorRatio -XX:MaxTenuringThreshold\uff0c\u8fd8\u9700\u8981\u6ce8\u610f JVM \u7684 GC\uff0cGC \u7684\u9738\u6c14\u5927\u5bb6\u90fd\u77e5\u9053\uff0c\u5c24\u5176\u662f full GC\uff08\u8fd8\u6574\u7406\u5185\u5b58\u788e\u7247\uff09\uff0c\u4ed6\u5c31\u50cf\u201c\u6050\u9f99\u7279\u7ea7\u514b\u8d5b\u53f7\u201d\u4e00\u6837\uff0c\u4ed6\u8fd0\u884c\u7684\u65f6\u5019\uff0c\u6574\u4e2a\u4e16\u754c\u7684\u65f6\u95f4\u90fd\u505c\u6b62\u4e86\u3002<\/p>\n<h4 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u7f51\u7edc\u8c03\u4f18\">\u7f51\u7edc\u8c03\u4f18<\/h4>\n<p>\u5173\u4e8e\u7f51\u7edc\u8c03\u4f18\uff0c\u5c24\u5176\u662f TCP Tuning\uff08\u4f60\u53ef\u4ee5\u4ee5\u8fd9\u4e24\u4e2a\u5173\u952e\u8bcd\u5728\u7f51\u4e0a\u627e\u5230\u5f88\u591a\u6587\u7ae0\uff09\uff0c\u8fd9\u91cc\u9762\u6709\u5f88\u591a\u5f88\u591a\u4e1c\u897f\u53ef\u4ee5\u8bf4\u3002\u770b\u770b Linux \u4e0b TCP\/IP \u7684\u90a3\u4e48\u591a\u53c2\u6570\u5c31\u77e5\u9053\u4e86\uff08\u987a\u4fbf\u8bf4\u4e00\u4e0b\uff0c\u4f60\u4e5f\u8bb8\u4e0d\u559c\u6b22 Linux\uff0c\u4f46\u662f\u4f60\u4e0d\u80fd\u5426\u8ba4 Linux \u7ed9\u6211\u4eec\u4e86\u5f88\u591a\u53ef\u4ee5\u8fdb\u884c\u5185\u6838\u8c03\u4f18\u7684\u6743\u529b\uff09\u3002\u5f3a\u70c8\u5efa\u8bae\u5927\u5bb6\u770b\u770b\u300aTCP\/IP \u8be6\u89e3 \u5377 1: \u534f\u8bae\u300b\u8fd9\u672c\u4e66\u3002\u6211\u5728\u8fd9\u91cc\u53ea\u8bb2\u4e00\u4e9b\u6982\u5ff5\u4e0a\u7684\u4e1c\u897f\u3002<\/p>\n<h5 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-TCP\u8c03\u4f18\">\u00a0\u00a0TCP \u8c03\u4f18<\/h5>\n<p>\u6211\u4eec\u77e5\u9053 TCP \u94fe\u63a5\u662f\u6709\u5f88\u591a\u5f00\u9500\u7684\uff0c\u4e00\u4e2a\u662f\u4f1a\u5360\u7528\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u53e6\u4e00\u4e2a\u662f\u4f1a\u5f00\u7f13\u5b58\uff0c\u4e00\u822c\u6765\u8bf4\u4e00\u4e2a\u7cfb\u7edf\u53ef\u4ee5\u652f\u6301\u7684 TCP \u94fe\u63a5\u6570\u662f\u6709\u9650\u7684\uff0c\u6211\u4eec\u9700\u8981\u6e05\u695a\u5730\u8ba4\u8bc6\u5230 TCP \u94fe\u63a5\u5bf9\u7cfb\u7edf\u7684\u5f00\u9500\u662f\u5f88\u5927\u7684\u3002\u6b63\u662f\u56e0\u4e3a TCP \u662f\u8017\u8d44\u6e90\u7684\uff0c\u6240\u4ee5\uff0c\u5f88\u591a\u653b\u51fb\u90fd\u662f\u8ba9\u4f60\u7cfb\u7edf\u4e0a\u51fa\u73b0\u5927\u91cf\u7684 TCP \u94fe\u63a5\uff0c\u628a\u4f60\u7684\u7cfb\u7edf\u8d44\u6e90\u8017\u5c3d\u3002\u6bd4\u5982\u8457\u540d\u7684 SYNC Flood \u653b\u51fb\u3002<\/p>\n<p>\u6240\u4ee5\uff0c\u6211\u4eec\u8981\u6ce8\u610f\u914d\u7f6e KeepAlive \u53c2\u6570\uff0c\u8fd9\u4e2a\u53c2\u6570\u7684\u610f\u601d\u662f\u5b9a\u4e49\u4e00\u4e2a\u65f6\u95f4\uff0c\u5982\u679c\u94fe\u63a5\u4e0a\u6ca1\u6709\u6570\u636e\u4f20\u8f93\uff0c\u7cfb\u7edf\u4f1a\u5728\u8fd9\u4e2a\u65f6\u95f4\u53d1\u4e00\u4e2a\u5305\uff0c\u5982\u679c\u6ca1\u6709\u6536\u5230\u56de\u5e94\uff0c\u90a3\u4e48 TCP \u5c31\u8ba4\u4e3a\u94fe\u63a5\u65ad\u4e86\uff0c\u7136\u540e\u5c31\u4f1a\u628a\u94fe\u63a5\u5173\u95ed\uff0c\u8fd9\u6837\u53ef\u4ee5\u56de\u6536\u7cfb\u7edf\u8d44\u6e90\u5f00\u9500\u3002\uff08\u6ce8\uff1aHTTP \u5c42\u4e0a\u4e5f\u6709 KeepAlive \u53c2\u6570\uff09\u5bf9\u4e8e\u50cf HTTP \u8fd9\u6837\u7684\u77ed\u94fe\u63a5\uff0c\u8bbe\u7f6e\u4e00\u4e2a 1-2 \u5206\u949f\u7684 keepalive \u975e\u5e38\u91cd\u8981\u3002\u8fd9\u53ef\u4ee5\u5728\u4e00\u5b9a\u7a0b\u5ea6\u4e0a\u9632\u6b62 DoS \u653b\u51fb\u3002\u6709\u4e0b\u9762\u51e0\u4e2a\u53c2\u6570\uff08\u4e0b\u9762\u8fd9\u4e9b\u53c2\u6570\u7684\u503c\u4ec5\u4f9b\u53c2\u8003\uff09\uff1a<\/p>\n<pre><code>net.ipv4.tcp_keepalive_probes = 5\r\nnet.ipv4.tcp_keepalive_intvl = 20\r\nnet.ipv4.tcp_fin_timeout = 30<\/code><\/pre>\n<p>\u5bf9\u4e8e TCP \u7684 TIME_WAIT \u8fd9\u4e2a\u72b6\u6001\uff0c\u4e3b\u52a8\u5173\u95ed\u7684\u4e00\u65b9\u8fdb\u5165 TIME_WAIT \u72b6\u6001\uff0cTIME_WAIT \u72b6\u6001\u5c06\u6301\u7eed 2 \u4e2a MSL(Max Segment Lifetime)\uff0c\u9ed8\u8ba4\u4e3a 4 \u5206\u949f\uff0cTIME_WAIT \u72b6\u6001\u4e0b\u7684\u8d44\u6e90\u4e0d\u80fd\u56de\u6536\u3002\u6709\u5927\u91cf\u7684 TIME_WAIT \u94fe\u63a5\u7684\u60c5\u51b5\u4e00\u822c\u662f\u5728 HTTP \u670d\u52a1\u5668\u4e0a\u3002\u5bf9\u6b64\uff0c\u6709\u4e24\u4e2a\u53c2\u6570\u9700\u8981\u6ce8\u610f\uff0c<\/p>\n<pre><code>net.ipv4.tcp_tw_reuse=1\r\nnet.ipv4.tcp_tw_recycle=1<\/code><\/pre>\n<p>\u524d\u8005\u8868\u793a\u91cd\u7528 TIME_WAIT\uff0c\u540e\u8005\u8868\u793a\u56de\u6536 TIME_WAIT \u7684\u8d44\u6e90\u3002<\/p>\n<p>TCP \u8fd8\u6709\u4e00\u4e2a\u91cd\u8981\u7684\u6982\u5ff5\u53eb RWIN\uff08TCP Receive Window Size\uff09\uff0c\u8fd9\u4e2a\u4e1c\u897f\u7684\u610f\u601d\u662f\uff0c\u6211\u4e00\u4e2a TCP \u94fe\u63a5\u5728\u6ca1\u6709\u5411 Sender \u53d1\u51fa ack \u65f6\u53ef\u4ee5\u63a5\u6536\u5230\u7684\u6700\u5927\u7684\u6570\u636e\u5305\u3002\u4e3a\u4ec0\u4e48\u8fd9\u4e2a\u5f88\u91cd\u8981\uff1f\u56e0\u4e3a\u5982\u679c Sender \u6ca1\u6709\u6536\u5230 Receiver \u53d1\u8fc7\u6765 ack\uff0cSender \u5c31\u4f1a\u505c\u6b62\u53d1\u9001\u6570\u636e\u5e76\u4f1a\u7b49\u4e00\u6bb5\u65f6\u95f4\uff0c\u5982\u679c\u8d85\u65f6\uff0c\u90a3\u4e48\u5c31\u4f1a\u91cd\u4f20\u3002\u8fd9\u5c31\u662f\u4e3a\u4ec0\u4e48 TCP \u94fe\u63a5\u662f\u53ef\u9760\u94fe\u63a5\u7684\u539f\u56e0\u3002\u91cd\u4f20\u8fd8\u4e0d\u662f\u6700\u4e25\u91cd\u7684\uff0c\u5982\u679c\u6709\u4e22\u5305\u53d1\u751f\u7684\u8bdd\uff0cTCP \u7684\u5e26\u5bbd\u4f7f\u7528\u7387\u4f1a\u9a6c\u4e0a\u53d7\u5230\u5f71\u54cd\uff08\u4f1a\u76f2\u76ee\u51cf\u534a\uff09\uff0c\u518d\u4e22\u5305\uff0c\u518d\u51cf\u534a\uff0c\u7136\u540e\u5982\u679c\u4e0d\u4e22\u5305\u4e86\uff0c\u5c31\u9010\u6b65\u6062\u590d\u3002\u76f8\u5173\u53c2\u6570\u5982\u4e0b\uff1a<\/p>\n<pre><code>net.core.wmem_default = 8388608\r\nnet.core.rmem_default = 8388608\r\nnet.core.rmem_max = 16777216\r\nnet.core.wmem_max = 16777216<\/code><\/pre>\n<p>\u4e00\u822c\u6765\u8bf4\uff0c\u7406\u8bba\u4e0a\u7684 RWIN \u5e94\u8be5\u8bbe\u7f6e\u6210\uff1a\u541e\u5410\u91cf \u00a0* \u56de\u8def\u65f6\u95f4\u3002Sender \u7aef\u7684 buffer \u5e94\u8be5\u548c RWIN \u6709\u4e00\u6837\u7684\u5927\u5c0f\uff0c\u56e0\u4e3a Sender \u7aef\u53d1\u9001\u5b8c\u6570\u636e\u540e\u8981\u7b49 Receiver \u7aef\u786e\u8ba4\uff0c\u5982\u679c\u7f51\u7edc\u5ef6\u65f6\u5f88\u5927\uff0cbuffer \u8fc7\u5c0f\u4e86\uff0c\u786e\u8ba4\u7684\u6b21\u6570\u5c31\u4f1a\u591a\uff0c\u4e8e\u662f\u6027\u80fd\u5c31\u4e0d\u9ad8\uff0c\u5bf9\u7f51\u7edc\u7684\u5229\u7528\u7387\u4e5f\u5c31\u4e0d\u9ad8\u4e86\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u5bf9\u4e8e\u5ef6\u8fdf\u5927\u7684\u7f51\u7edc\uff0c\u6211\u4eec\u9700\u8981\u5927\u7684 buffer\uff0c\u8fd9\u6837\u53ef\u4ee5\u5c11\u4e00\u70b9 ack\uff0c\u591a\u4e00\u4e9b\u6570\u636e\uff0c\u5bf9\u4e8e\u54cd\u5e94\u5feb\u4e00\u70b9\u7684\u7f51\u7edc\uff0c\u53ef\u4ee5\u5c11\u4e00\u4e9b buffer\u3002<\/p>\n<p>\u56e0\u4e3a\uff0c\u5982\u679c\u6709\u4e22\u5305\uff08\u6ca1\u6709\u6536\u5230 ack\uff09\uff0cbuffer \u8fc7\u5927\u53ef\u80fd\u4f1a\u6709\u95ee\u9898\uff0c\u56e0\u4e3a\u8fd9\u4f1a\u8ba9 TCP \u91cd\u4f20\u6240\u6709\u7684\u6570\u636e\uff0c\u53cd\u800c\u5f71\u54cd\u7f51\u7edc\u6027\u80fd\u3002\uff08\u5f53\u7136\uff0c\u7f51\u7edc\u5dee\u7684\u60c5\u51b5\u4e0b\uff0c\u5c31\u522b\u73a9\u4ec0\u4e48\u9ad8\u6027\u80fd\u4e86\uff09 \u6240\u4ee5\uff0c\u9ad8\u6027\u80fd\u7684\u7f51\u7edc\u91cd\u8981\u7684\u662f\u8981\u8ba9\u7f51\u7edc\u4e22\u5305\u7387\u975e\u5e38\u975e\u5e38\u5730\u5c0f\uff08\u57fa\u672c\u4e0a\u662f\u7528\u5728 LAN \u91cc\uff09\uff0c\u5982\u679c\u7f51\u7edc\u57fa\u672c\u662f\u53ef\u4fe1\u7684\uff0c\u8fd9\u6837\u7528\u5927\u4e00\u70b9\u7684 buffer \u4f1a\u6709\u66f4\u597d\u7684\u7f51\u7edc\u4f20\u8f93\u6027\u80fd\uff08\u6765\u6765\u56de\u56de\u592a\u591a\u592a\u5f71\u54cd\u6027\u80fd\u4e86\uff09\u3002<\/p>\n<p>\u53e6\u5916\uff0c\u6211\u4eec\u60f3\u4e00\u60f3\uff0c\u5982\u679c\u7f51\u7edc\u8d28\u91cf\u975e\u5e38\u597d\uff0c\u57fa\u672c\u4e0d\u4e22\u5305\uff0c\u800c\u4e1a\u52a1\u4e0a\u6211\u4eec\u4e0d\u6015\u5076\u5c14\u4e22\u51e0\u4e2a\u5305\uff0c\u5982\u679c\u662f\u8fd9\u6837\u7684\u8bdd\uff0c\u90a3\u4e48\uff0c\u6211\u4eec\u4e3a\u4ec0\u4e48\u4e0d\u7528\u901f\u5ea6\u66f4\u5feb\u7684 UDP \u5462\uff1f\u4f60\u60f3\u8fc7\u8fd9\u4e2a\u95ee\u9898\u4e86\u5417\uff1f<\/p>\n<h5 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-UDP\u8c03\u4f18\">\u00a0\u00a0UDP \u8c03\u4f18<\/h5>\n<p>\u8bf4\u5230 UDP \u7684\u8c03\u4f18\uff0c\u6709\u4e00\u4e9b\u4e8b\u6211\u60f3\u91cd\u70b9\u8bf4\u4e00\u6837\uff0c\u90a3\u5c31\u662f MTU\u2014\u2014\u6700\u5927\u4f20\u8f93\u5355\u5143\uff08\u5176\u5b9e\u8fd9\u5bf9 TCP \u4e5f\u4e00\u6837\uff0c\u56e0\u4e3a\u8fd9\u662f\u94fe\u8def\u5c42\u4e0a\u7684\u4e1c\u897f\uff09\u3002\u6240\u8c13\u6700\u5927\u4f20\u8f93\u5355\u5143\uff0c\u4f60\u53ef\u4ee5\u60f3\u50cf\u6210\u662f\u516c\u8def\u4e0a\u7684\u516c\u4ea4\u8f66\uff0c\u5047\u8bbe\u4e00\u4e2a\u516c\u4ea4\u8f66\u53ef\u4ee5\u6700\u591a\u5750 70 \u4eba\uff0c\u5e26\u5bbd\u5c31\u50cf\u662f\u516c\u8def\u7684\u8f66\u9053\u6570\u4e00\u6837\uff0c\u5982\u679c\u4e00\u6761\u8def\u4e0a\u6700\u591a\u53ef\u4ee5\u5bb9\u4e0b 100 \u8f86\u516c\u4ea4\u8f66\uff0c\u90a3\u610f\u5473\u7740\u6211\u6700\u591a\u53ef\u4ee5\u8fd0\u9001 7000 \u4eba\uff0c\u4f46\u662f\u5982\u679c\u516c\u4ea4\u8f66\u5750\u4e0d\u6ee1\uff0c\u6bd4\u5982\u5e73\u5747\u6bcf\u8f86\u8f66\u53ea\u6709 20 \u4eba\uff0c\u90a3\u4e48\u6211\u53ea\u8fd0\u9001\u4e86 2000 \u4eba\uff0c\u4e8e\u662f\u6211\u516c\u8def\u8d44\u6e90\uff08\u5e26\u5bbd\u8d44\u6e90\uff09\u5c31\u88ab\u6d6a\u8d39\u4e86\u3002 \u6240\u4ee5\uff0c\u6211\u4eec\u5bf9\u4e8e\u4e00\u4e2a UDP \u7684\u5305\uff0c\u6211\u4eec\u8981\u5c3d\u91cf\u5730\u8ba9\u4ed6\u5927\u5230 MTU \u7684\u6700\u5927\u5c3a\u5bf8\u518d\u5f80\u7f51\u7edc\u4e0a\u4f20\uff0c\u8fd9\u6837\u53ef\u4ee5\u6700\u5927\u5316\u5e26\u5bbd\u5229\u7528\u7387\u3002<\/p>\n<p>\u5bf9\u4e8e\u8fd9\u4e2a MTU\uff0c\u4ee5\u592a\u7f51\u662f 1500 \u5b57\u8282\uff0c\u5149\u7ea4\u662f 4352 \u5b57\u8282\uff0c802.11 \u65e0\u7ebf\u7f51\u662f 7981\u3002\u4f46\u662f\uff0c\u5f53\u6211\u4eec\u7528 TCP\/UDP \u53d1\u5305\u7684\u65f6\u5019\uff0c\u6211\u4eec\u7684\u6709\u6548\u8d1f\u8f7d Payload \u8981\u4f4e\u4e8e\u8fd9\u4e2a\u503c\uff0c\u56e0\u4e3a IP \u534f\u8bae\u4f1a\u52a0\u4e0a 20 \u4e2a\u5b57\u8282\uff0cUDP \u4f1a\u52a0\u4e0a 8 \u4e2a\u5b57\u8282\uff08TCP \u52a0\u7684\u66f4\u591a\uff09\uff0c\u6240\u4ee5\uff0c\u4e00\u822c\u6765\u8bf4\uff0c\u4f60\u7684\u4e00\u4e2a UDP \u5305\u7684\u6700\u5927\u5e94\u8be5\u662f 1500-8-20=1472\uff0c\u8fd9\u662f\u4f60\u7684\u6570\u636e\u7684\u5927\u5c0f\u3002\u5f53\u7136\uff0c\u5982\u679c\u4f60\u7528\u5149\u7ea4\u7684\u8bdd\uff0c \u8fd9\u4e2a\u503c\u5c31\u53ef\u4ee5\u66f4\u5927\u4e00\u4e9b\u3002\uff08\u987a\u4fbf\u8bf4\u4e00\u4e0b\uff0c\u5bf9\u4e8e\u67d0\u4e9b NB \u7684\u5343\u5149\u4ee5\u6001\u7f51\u7f51\u5361\u6765\u8bf4\uff0c\u5728\u7f51\u5361\u4e0a\uff0c\u7f51\u5361\u786c\u4ef6\u5982\u679c\u53d1\u73b0\u4f60\u7684\u5305\u7684\u5927\u5c0f\u8d85\u8fc7\u4e86 MTU\uff0c\u5176\u4f1a\u5e2e\u4f60\u505a fragment\uff0c\u5230\u4e86\u76ee\u6807\u7aef\u53c8\u4f1a\u5e2e\u4f60\u505a\u91cd\u7ec4\uff0c\u8fd9\u5c31\u4e0d\u9700\u8981\u4f60\u5728\u7a0b\u5e8f\u4e2d\u5904\u7406\u4e86\uff09<\/p>\n<p>\u518d\u591a\u8bf4\u4e00\u4e0b\uff0c\u4f7f\u7528 Socket \u7f16\u7a0b\u7684\u65f6\u5019\uff0c\u4f60\u53ef\u4ee5\u4f7f\u7528 setsockopt() \u8bbe\u7f6e SO_SNDBUF\/SO_RCVBUF \u7684\u5927\u5c0f\uff0cTTL \u548c KeepAlive \u8fd9\u4e9b\u5173\u952e\u7684\u8bbe\u7f6e\uff0c\u5f53\u7136\uff0c\u8fd8\u6709\u5f88\u591a\uff0c\u5177\u4f53\u4f60\u53ef\u4ee5\u67e5\u770b\u4e00\u4e0b Socket \u7684\u624b\u518c\u3002<\/p>\n<p>\u6700\u540e\u8bf4\u4e00\u70b9\uff0cUDP \u8fd8\u6709\u4e00\u4e2a\u6700\u5927\u7684\u597d\u5904\u662f multi-cast \u591a\u64ad\uff0c\u8fd9\u4e2a\u6280\u672f\u5bf9\u4e8e\u4f60\u9700\u8981\u5728\u5185\u7f51\u91cc\u901a\u77e5\u591a\u53f0\u7ed3\u70b9\u65f6\u975e\u5e38\u65b9\u4fbf\u548c\u9ad8\u6548\u3002\u800c\u4e14\uff0c\u591a\u64ad\u8fd9\u79cd\u6280\u672f\u5bf9\u4e8e\u673a\u4f1a\u7684\u6c34\u5e73\u6269\u5c55\uff08\u9700\u8981\u589e\u52a0\u673a\u5668\u6765\u4fa6\u542c\u591a\u64ad\u4fe1\u606f\uff09\u4e5f\u5f88\u6709\u5229\u3002<\/p>\n<h5 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u7f51\u5361\u8c03\u4f18\">\u00a0\u00a0\u7f51\u5361\u8c03\u4f18<\/h5>\n<p>\u5bf9\u4e8e\u7f51\u5361\uff0c\u6211\u4eec\u4e5f\u662f\u53ef\u4ee5\u8c03\u4f18\u7684\uff0c\u8fd9\u5bf9\u4e8e\u5343\u5146\u4ee5\u53ca\u7f51\u7f51\u5361\u975e\u5e38\u5fc5\u8981\uff0c\u5728 Linux \u4e0b\uff0c\u6211\u4eec\u53ef\u4ee5\u7528 ifconfig \u67e5\u770b\u7f51\u4e0a\u7684\u7edf\u8ba1\u4fe1\u606f\uff0c\u5982\u679c\u6211\u4eec\u770b\u5230 overrun \u4e0a\u6709\u6570\u636e\uff0c\u6211\u4eec\u5c31\u53ef\u80fd\u9700\u8981\u8c03\u6574\u4e00\u4e0b txqueuelen \u7684\u5c3a\u5bf8\uff08\u4e00\u822c\u9ed8\u8ba4\u4e3a 1000\uff09\uff0c\u6211\u4eec\u53ef\u4ee5\u8c03\u5927\u4e00\u4e9b\uff0c\u5982\uff1aifconfig eth0 txqueuelen 5000\u3002Linux \u4e0b\u8fd8\u6709\u4e00\u4e2a\u547d\u4ee4\u53eb\uff1aethtool \u53ef\u4ee5\u7528\u4e8e\u8bbe\u7f6e\u7f51\u5361\u7684\u7f13\u51b2\u533a\u5927\u5c0f\u3002\u5728 Windows \u4e0b\uff0c\u6211\u4eec\u53ef\u4ee5\u5728\u7f51\u5361\u9002\u914d\u5668\u4e2d\u7684\u9ad8\u7ea7\u9009\u9879\u5361\u4e2d\u8c03\u6574\u76f8\u5173\u7684\u53c2\u6570\uff08\u5982\uff1aReceive Buffers, Transmit Buffer \u7b49\uff0c\u4e0d\u540c\u7684\u7f51\u5361\u6709\u4e0d\u540c\u7684\u53c2\u6570\uff09\u3002\u628a Buffer \u8c03\u5927\u5bf9\u4e8e\u9700\u8981\u5927\u6570\u636e\u91cf\u7684\u7f51\u7edc\u4f20\u8f93\u975e\u5e38\u6709\u6548\u3002<\/p>\n<h5 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u5176\u5b83\u7f51\u7edc\u6027\u80fd\">\u00a0\u00a0\u5176\u5b83\u7f51\u7edc\u6027\u80fd<\/h5>\n<p>\u5173\u4e8e\u591a\u8def\u590d\u7528\u6280\u672f\uff0c\u4e5f\u5c31\u662f\u7528\u4e00\u4e2a\u7ebf\u7a0b\u6765\u7ba1\u7406\u6240\u6709\u7684 TCP \u94fe\u63a5\uff0c\u6709\u4e09\u4e2a\u7cfb\u7edf\u8c03\u7528\u8981\u91cd\u70b9\u6ce8\u610f\uff1a\u4e00\u4e2a\u662f select\uff0c\u8fd9\u4e2a\u7cfb\u7edf\u8c03\u7528\u53ea\u652f\u6301\u4e0a\u9650 1024 \u4e2a\u94fe\u63a5\uff0c\u7b2c\u4e8c\u4e2a\u662f poll\uff0c\u5176\u53ef\u4ee5\u7a81\u7834 1024 \u7684\u9650\u5236\uff0c\u4f46\u662f select \u548c poll \u672c\u8d28\u4e0a\u662f\u4f7f\u7528\u7684\u8f6e\u8be2\u673a\u5236\uff0c\u8f6e\u8be2\u673a\u5236\u5728\u94fe\u63a5\u591a\u7684\u65f6\u5019\u6027\u80fd\u5f88\u5dee\uff0c\u56e0\u4e3b\u662f O(n) \u7684\u7b97\u6cd5\uff0c\u6240\u4ee5\uff0cepoll \u51fa\u73b0\u4e86\uff0cepoll \u662f\u64cd\u4f5c\u7cfb\u7edf\u5185\u6838\u652f\u6301\u7684\uff0c\u4ec5\u5f53\u5728\u94fe\u63a5\u6d3b\u8dc3\u65f6\uff0c\u64cd\u4f5c\u7cfb\u7edf\u624d\u4f1a callback\uff0c\u8fd9\u662f\u7531\u64cd\u4f5c\u7cfb\u7edf\u901a\u77e5\u89e6\u53d1\u7684\uff0c\u4f46\u5176\u53ea\u6709 Linux Kernel 2.6 \u4ee5\u540e\u624d\u652f\u6301\uff08\u51c6\u786e\u8bf4\u662f 2.5.44 \u4e2d\u5f15\u5165\u7684\uff09\uff0c\u5f53\u7136\uff0c\u5982\u679c\u6240\u6709\u7684\u94fe\u63a5\u90fd\u662f\u6d3b\u8dc3\u7684\uff0c\u8fc7\u591a\u7684\u4f7f\u7528 epoll_ctl \u53ef\u80fd\u4f1a\u6bd4\u8f6e\u8be2\u7684\u65b9\u5f0f\u8fd8\u5f71\u54cd\u6027\u80fd\uff0c\u4e0d\u8fc7\u5f71\u54cd\u7684\u4e0d\u5927\u3002<\/p>\n<p>\u53e6\u5916\uff0c\u5173\u4e8e\u4e00\u4e9b\u548c DNS Lookup \u7684\u7cfb\u7edf\u8c03\u7528\u8981\u5c0f\u5fc3\uff0c\u6bd4\u5982\uff1agethostbyaddr\/gethostbyname\uff0c\u8fd9\u4e2a\u51fd\u6570\u53ef\u80fd\u4f1a\u76f8\u5f53\u7684\u8d39\u65f6\uff0c\u56e0\u4e3a\u5176\u8981\u5230\u7f51\u7edc\u4e0a\u53bb\u627e\u57df\u540d\uff0c\u56e0\u4e3a DNS \u7684\u9012\u5f52\u67e5\u8be2\uff0c\u4f1a\u5bfc\u81f4\u4e25\u91cd\u8d85\u65f6\uff0c\u800c\u53c8\u4e0d\u80fd\u901a\u8fc7\u8bbe\u7f6e\u4ec0\u4e48\u53c2\u6570\u6765\u8bbe\u7f6e time out\uff0c\u5bf9\u6b64\u4f60\u53ef\u4ee5\u901a\u8fc7\u914d\u7f6e hosts \u6587\u4ef6\u6765\u52a0\u5feb\u901f\u5ea6\uff0c\u6216\u662f\u81ea\u5df1\u5728\u5185\u5b58\u4e2d\u7ba1\u7406\u5bf9\u5e94\u8868\uff0c\u5728\u7a0b\u5e8f\u542f\u52a8\u65f6\u67e5\u597d\uff0c\u800c\u4e0d\u8981\u5728\u8fd0\u884c\u65f6\u6bcf\u6b21\u90fd\u67e5\u3002<\/p>\n<p>\u53e6\u5916\uff0c\u5728\u591a\u7ebf\u7a0b\u4e0b\u9762\uff0cgethostbyname \u4f1a\u4e00\u4e2a\u66f4\u4e25\u91cd\u7684\u95ee\u9898\uff0c\u5c31\u662f\u5982\u679c\u6709\u4e00\u4e2a\u7ebf\u7a0b\u7684 gethostbyname \u53d1\u751f\u963b\u585e\uff0c\u5176\u5b83\u7ebf\u7a0b\u90fd\u4f1a\u5728 gethostbyname \u5904\u53d1\u751f\u963b\u585e\uff0c\u8fd9\u4e2a\u6bd4\u8f83\u53d8\u6001\uff0c\u8981\u5c0f\u5fc3\u3002\uff08\u4f60\u53ef\u4ee5\u8bd5\u8bd5 GNU \u7684 gethostbyname_r()\uff0c\u8fd9\u4e2a\u7684\u6027\u80fd\u8981\u597d\u4e00\u4e9b\uff09 \u8fd9\u79cd\u5230\u7f51\u4e0a\u627e\u4fe1\u606f\u7684\u4e1c\u897f\u5f88\u591a\uff0c\u6bd4\u5982\uff0c\u5982\u679c\u4f60\u7684 Linux \u4f7f\u7528\u4e86 NIS\uff0c\u6216\u662f NFS\uff0c\u67d0\u4e9b\u7528\u6237\u6216\u6587\u4ef6\u76f8\u5173\u7684\u7cfb\u7edf\u8c03\u7528\u5c31\u5f88\u6162\uff0c\u6240\u4ee5\u8981\u5c0f\u5fc3\u3002<\/p>\n<h4 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u7cfb\u7edf\u8c03\u4f18\">\u7cfb\u7edf\u8c03\u4f18<\/h4>\n<h5 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-I\/O\u6a21\u578b\">\u00a0\u00a0 I\/O \u6a21\u578b<\/h5>\n<p>\u524d\u9762\u8bf4\u5230\u8fc7 select\/poll\/epoll \u8fd9\u4e09\u4e2a\u7cfb\u7edf\u8c03\u7528\uff0c\u6211\u4eec\u90fd\u77e5\u9053\uff0cUnix\/Linux \u4e0b\u628a\u6240\u6709\u7684\u8bbe\u5907\u90fd\u5f53\u6210\u6587\u4ef6\u6765\u8fdb\u884c I\/O\uff0c\u6240\u4ee5\uff0c\u90a3\u4e09\u4e2a\u64cd\u4f5c\u66f4\u5e94\u8be5\u7b97\u662f I\/O \u76f8\u5173\u7684\u7cfb\u7edf\u8c03\u7528\u3002\u8bf4\u5230 \u00a0I\/O \u6a21\u578b\uff0c\u8fd9\u5bf9\u4e8e\u6211\u4eec\u7684 I\/O \u6027\u80fd\u76f8\u5f53\u91cd\u8981\uff0c\u6211\u4eec\u77e5\u9053\uff0cUnix\/Linux \u7ecf\u5178\u7684 I\/O \u65b9\u5f0f\u662f\uff1a<\/p>\n<p>\u7b2c\u4e00\u79cd\uff0c\u540c\u6b65\u963b\u585e\u5f0f I\/O\uff0c\u8fd9\u4e2a\u4e0d\u8bf4\u4e86\u3002<\/p>\n<p>\u7b2c\u4e8c\u79cd\uff0c\u540c\u6b65\u65e0\u963b\u585e\u65b9\u5f0f\u3002\u5176\u901a\u8fc7 fctnl \u8bbe\u7f6e O_NONBLOCK \u6765\u5b8c\u6210\u3002<\/p>\n<p>\u7b2c\u4e09\u79cd\uff0c\u5bf9\u4e8e select\/poll\/epoll \u8fd9\u4e09\u4e2a\u662f I\/O \u4e0d\u963b\u585e\uff0c\u4f46\u662f\u5728\u4e8b\u4ef6\u4e0a\u963b\u585e\uff0c\u7b97\u662f\uff1aI\/O \u5f02\u6b65\uff0c\u4e8b\u4ef6\u540c\u6b65\u7684\u8c03\u7528\u3002<\/p>\n<p>\u7b2c\u56db\u79cd\uff0cAIO \u65b9\u5f0f\u3002\u8fd9\u79cd I\/O \u6a21\u578b\u662f\u4e00\u79cd\u5904\u7406\u4e0e I\/O \u5e76\u884c\u7684\u6a21\u578b\u3002I\/O \u8bf7\u6c42\u4f1a\u7acb\u5373\u8fd4\u56de\uff0c\u8bf4\u660e\u8bf7\u6c42\u5df2\u7ecf\u6210\u529f\u53d1\u8d77\u4e86\u3002\u5728\u540e\u53f0\u5b8c\u6210 I\/O \u64cd\u4f5c\u65f6\uff0c\u5411\u5e94\u7528\u7a0b\u5e8f\u53d1\u8d77\u901a\u77e5\uff0c\u901a\u77e5\u6709\u4e24\u79cd\u65b9\u5f0f\uff1a\u4e00\u79cd\u662f\u4ea7\u751f\u4e00\u4e2a\u4fe1\u53f7\uff0c\u53e6\u4e00\u79cd\u662f\u6267\u884c\u4e00\u4e2a\u57fa\u4e8e\u7ebf\u7a0b\u7684\u56de\u8c03\u51fd\u6570\u6765\u5b8c\u6210\u8fd9\u6b21 I\/O \u5904\u7406\u8fc7\u7a0b\u3002<\/p>\n<p>\u7b2c\u56db\u79cd\u56e0\u4e3a\u6ca1\u6709\u4efb\u4f55\u7684\u963b\u585e\uff0c\u65e0\u8bba\u662f I\/O \u4e0a\uff0c\u8fd8\u662f\u4e8b\u4ef6\u901a\u77e5\u4e0a\uff0c\u6240\u4ee5\uff0c\u5176\u53ef\u4ee5\u8ba9\u4f60\u5145\u5206\u5730\u5229\u7528 CPU\uff0c\u6bd4\u8d77\u7b2c\u4e8c\u79cd\u540c\u6b65\u65e0\u963b\u585e\u597d\u5904\u5c31\u662f\uff0c\u7b2c\u4e8c\u79cd\u8981\u4f60\u4e00\u904d\u4e00\u904d\u5730\u53bb\u8f6e\u8be2\u3002Nginx \u4e4b\u6240\u6240\u4ee5\u9ad8\u6548\uff0c\u662f\u5176\u4f7f\u7528\u4e86 epoll \u548c AIO \u7684\u65b9\u5f0f\u6765\u8fdb\u884c I\/O \u7684\u3002<\/p>\n<p>\u518d\u8bf4\u4e00\u4e0b Windows \u4e0b\u7684 I\/O \u6a21\u578b\uff0c<\/p>\n<p>a\uff09\u4e00\u4e2a\u662f WriteFile \u7cfb\u7edf\u8c03\u7528\uff0c\u8fd9\u4e2a\u7cfb\u7edf\u8c03\u7528\u53ef\u4ee5\u662f\u540c\u6b65\u963b\u585e\u7684\uff0c\u4e5f\u53ef\u4ee5\u662f\u540c\u6b65\u65e0\u963b\u585e\u7684\uff0c\u5173\u4e8e\u770b\u6587\u4ef6\u662f\u4e0d\u662f\u4ee5 Overlapped \u6253\u5f00\u7684\u3002\u5173\u4e8e\u540c\u6b65\u65e0\u963b\u585e\uff0c\u9700\u8981\u8bbe\u7f6e\u5176\u6700\u540e\u4e00\u4e2a\u53c2\u6570 Overlapped\uff0c\u5fae\u8f6f\u53eb Overlapped I\/O\uff0c\u4f60\u9700\u8981 WaitForSingleObject \u624d\u80fd\u77e5\u9053\u6709\u6ca1\u6709\u5199\u5b8c\u6210\u3002\u8fd9\u4e2a\u7cfb\u7edf\u8c03\u7528\u7684\u6027\u80fd\u53ef\u60f3\u800c\u77e5\u3002<\/p>\n<p>b\uff09\u53e6\u4e00\u4e2a\u53eb WriteFileEx \u7684\u7cfb\u7edf\u8c03\u7528\uff0c\u5176\u53ef\u4ee5\u5b9e\u73b0\u5f02\u6b65 I\/O\uff0c\u5e76\u53ef\u4ee5\u8ba9\u4f60\u4f20\u5165\u4e00\u4e2a callback \u51fd\u6570\uff0c\u7b49 I\/O \u7ed3\u675f\u540e\u56de\u8c03\u4e4b\uff0c \u4f46\u662f\u8fd9\u4e2a\u56de\u8c03\u7684\u8fc7\u7a0b Windows \u662f\u628a callback \u51fd\u6570\u653e\u5230\u4e86 APC\uff08Asynchronous Procedure Calls\uff09\u7684\u961f\u5217\u4e2d\uff0c\u7136\u540e\uff0c\u53ea\u7528\u5f53\u5e94\u7528\u7a0b\u5e8f\u5f53\u524d\u7ebf\u7a0b\u6210\u4e3a\u53ef\u88ab\u901a\u77e5\u72b6\u6001\uff08Alterable\uff09\u65f6\uff0c\u624d\u4f1a\u88ab\u56de\u8c03\u3002\u53ea\u6709\u5f53\u4f60\u7684\u7ebf\u7a0b\u4f7f\u7528\u4e86\u8fd9\u51e0\u4e2a\u51fd\u6570\u65f6 WaitForSingleObjectEx, WaitForMultipleObjectsEx, MsgWaitForMultipleObjectsEx, SignalObjectAndWait \u548c SleepEx\uff0c\u7ebf\u7a0b\u624d\u4f1a\u6210\u4e3a Alterable \u72b6\u6001\u3002\u53ef\u89c1\uff0c\u8fd9\u4e2a\u6a21\u578b\uff0c\u8fd8\u662f\u6709 wait\uff0c\u6240\u4ee5\u6027\u80fd\u4e5f\u4e0d\u9ad8\u3002<\/p>\n<p>c\uff09\u7136\u540e\u662f IOCP \u2013 IO Completion Port\uff0cIOCP \u4f1a\u628a I\/O \u7684\u7ed3\u679c\u653e\u5728\u4e00\u4e2a\u961f\u5217\u4e2d\uff0c\u4f46\u662f\uff0c\u4fa6\u542c\u8fd9\u4e2a\u961f\u5217\u7684\u4e0d\u662f\u4e3b\u7ebf\u7a0b\uff0c\u800c\u662f\u4e13\u95e8\u6765\u5e72\u8fd9\u4e2a\u4e8b\u7684\u4e00\u4e2a\u6216\u591a\u4e2a\u7ebf\u7a0b\u53bb\u5e72\uff08\u8001\u7684\u5e73\u53f0\u8981\u4f60\u81ea\u5df1\u521b\u5efa\u7ebf\u7a0b\uff0c\u65b0\u7684\u5e73\u53f0\u662f\u4f60\u53ef\u4ee5\u521b\u5efa\u4e00\u4e2a\u7ebf\u7a0b\u6c60\uff09\u3002IOCP \u662f\u4e00\u4e2a\u7ebf\u7a0b\u6c60\u6a21\u578b\u3002\u8fd9\u4e2a\u548c Linux \u4e0b\u7684 AIO \u6a21\u578b\u6bd4\u8f83\u76f8\u4f3c\uff0c\u4f46\u662f\u5b9e\u73b0\u65b9\u5f0f\u548c\u4f7f\u7528\u65b9\u5f0f\u5b8c\u5168\u4e0d\u4e00\u6837\u3002<\/p>\n<p>\u5f53\u7136\uff0c\u771f\u6b63\u63d0\u9ad8 I\/O \u6027\u80fd\u65b9\u5f0f\u662f\u628a\u548c\u5916\u8bbe\u7684 I\/O \u7684\u6b21\u6570\u964d\u5230\u6700\u4f4e\uff0c\u6700\u597d\u6ca1\u6709\uff0c\u6240\u4ee5\uff0c\u5bf9\u4e8e\u8bfb\u6765\u8bf4\uff0c\u5185\u5b58 cache \u901a\u5e38\u53ef\u4ee5\u4ece\u8d28\u4e0a\u63d0\u5347\u6027\u80fd\uff0c\u56e0\u4e3a\u5185\u5b58\u6bd4\u5916\u8bbe\u5feb\u592a\u591a\u4e86\u3002\u5bf9\u4e8e\u5199\u6765\u8bf4\uff0ccache \u4f4f\u8981\u5199\u7684\u6570\u636e\uff0c\u5c11\u5199\u51e0\u6b21\uff0c\u4f46\u662f cache \u5e26\u6765\u7684\u95ee\u9898\u5c31\u662f\u5b9e\u65f6\u6027\u7684\u95ee\u9898\uff0c\u4e5f\u5c31\u662f latency \u4f1a\u53d8\u5927\uff0c\u6211\u4eec\u9700\u8981\u5728\u5199\u7684\u6b21\u6570\u4e0a\u548c\u76f8\u5e94\u4e0a\u505a\u6743\u8861\u3002<\/p>\n<h5 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u591a\u6838CPU\u8c03\u4f18\u6587\u4ef6\u7cfb\u7edf\u8c03\u4f18\">\u00a0\u00a0\u591a\u6838 CPU \u8c03\u4f18\u6587\u4ef6\u7cfb\u7edf\u8c03\u4f18<\/h5>\n<p>\u5173\u4e8e CPU \u7684\u591a\u6838\u6280\u672f\uff0c\u6211\u4eec\u77e5\u9053\uff0cCPU0 \u662f\u5f88\u5173\u952e\u7684\uff0c\u5982\u679c 0 \u53f7 CPU \u88ab\u7528\u5f97\u8fc7\u72e0\u7684\u8bdd\uff0c\u522b\u7684 CPU \u6027\u80fd\u4e5f\u4f1a\u4e0b\u964d\uff0c\u56e0\u4e3a CPU0 \u662f\u6709\u8c03\u6574\u529f\u80fd\u7684\uff0c\u6240\u4ee5\uff0c\u6211\u4eec\u4e0d\u80fd\u4efb\u7531\u64cd\u4f5c\u7cfb\u7edf\u8d1f\u8f7d\u5747\u8861\uff0c\u56e0\u4e3a\u6211\u4eec\u81ea\u5df1\u66f4\u4e86\u89e3\u81ea\u5df1\u7684\u7a0b\u5e8f\uff0c\u6240\u4ee5\uff0c\u6211\u4eec\u53ef\u4ee5\u624b\u52a8\u5730\u4e3a\u5176\u5206\u914d CPU \u6838\uff0c\u800c\u4e0d\u4f1a\u8fc7\u591a\u5730\u5360\u7528 CPU0\uff0c\u6216\u662f\u8ba9\u6211\u4eec\u5173\u952e\u8fdb\u7a0b\u548c\u4e00\u5806\u522b\u7684\u8fdb\u7a0b\u6324\u5728\u4e00\u8d77\u3002<\/p>\n<ul class=\"list-paddingleft-2\">\n<li>\u5bf9\u4e8e Windows \u6765\u8bf4\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u201c\u4efb\u52a1\u7ba1\u7406\u5668\u201d\u4e2d\u7684\u201c\u8fdb\u7a0b\u201d\u800c\u4e2d\u53f3\u952e\u83dc\u5355\u4e2d\u7684\u201c\u8bbe\u7f6e\u76f8\u5173\u6027\u2026\u2026\u201d\uff08Set Affinity\u2026\uff09\u6765\u8bbe\u7f6e\u5e76\u9650\u5236\u8fd9\u4e2a\u8fdb\u7a0b\u80fd\u88ab\u8fd0\u884c\u5728\u54ea\u4e9b\u6838\u4e0a\u3002<\/li>\n<li>\u5bf9\u4e8e Linux \u6765\u8bf4\uff0c\u53ef\u4ee5\u4f7f\u7528 taskset \u547d\u4ee4\u6765\u8bbe\u7f6e\uff08\u4f60\u53ef\u4ee5\u901a\u8fc7\u5b89\u88c5 schedutils \u6765\u5b89\u88c5\u8fd9\u4e2a\u547d\u4ee4\uff1aapt-get install schedutils\uff09<\/li>\n<\/ul>\n<p>\u591a\u6838 CPU \u8fd8\u6709\u4e00\u4e2a\u6280\u672f\u53eb NUMA \u6280\u672f\uff08Non-Uniform Memory Access\uff09\u3002\u4f20\u7edf\u7684\u591a\u6838\u8fd0\u7b97\u662f\u4f7f\u7528 SMP(Symmetric Multi-Processor ) \u6a21\u5f0f\uff0c\u591a\u4e2a\u5904\u7406\u5668\u5171\u4eab\u4e00\u4e2a\u96c6\u4e2d\u7684\u5b58\u50a8\u5668\u548c I\/O \u603b\u7ebf\u3002\u4e8e\u662f\u5c31\u4f1a\u51fa\u73b0\u4e00\u81f4\u5b58\u50a8\u5668\u8bbf\u95ee\u7684\u95ee\u9898\uff0c\u4e00\u81f4\u6027\u901a\u5e38\u610f\u5473\u7740\u6027\u80fd\u95ee\u9898\u3002NUMA \u6a21\u5f0f\u4e0b\uff0c\u5904\u7406\u5668\u88ab\u5212\u5206\u6210\u591a\u4e2a node\uff0c \u6bcf\u4e2a node \u6709\u81ea\u5df1\u7684\u672c\u5730\u5b58\u50a8\u5668\u7a7a\u95f4\u3002\u5173\u4e8e NUMA \u7684\u4e00\u4e9b\u6280\u672f\u7ec6\u8282\uff0c\u4f60\u53ef\u4ee5\u67e5\u770b\u4e00\u4e0b\u8fd9\u7bc7\u6587\u7ae0\u300aLinux \u7684 NUMA \u6280\u672f\u300b\uff0c\u5728 Linux \u4e0b\uff0c\u5bf9 NUMA \u8c03\u4f18\u7684\u547d\u4ee4\u662f\uff1anumactl \u3002\u5982\u4e0b\u9762\u7684\u547d\u4ee4\uff1a\uff08\u6307\u5b9a\u547d\u4ee4\u201cmyprogram arg1 arg2\u201d\u8fd0\u884c\u5728 node 0 \u4e0a\uff0c\u5176\u5185\u5b58\u5206\u914d\u5728 node 0 \u548c 1 \u4e0a\uff09<\/p>\n<pre><code>numactl --cpubind=0 --membind=0,1 myprogram arg1 arg2<\/code><\/pre>\n<p>\u5f53\u7136\uff0c\u4e0a\u9762\u8fd9\u4e2a\u547d\u4ee4\u5e76\u4e0d\u597d\uff0c\u56e0\u4e3a\u5185\u5b58\u8de8\u8d8a\u4e86\u4e24\u4e2a node\uff0c\u8fd9\u975e\u5e38\u4e0d\u597d\u3002\u6700\u597d\u7684\u65b9\u5f0f\u662f\u53ea\u8ba9\u7a0b\u5e8f\u8bbf\u95ee\u548c\u81ea\u5df1\u8fd0\u884c\u4e00\u6837\u7684 node\uff0c\u5982\uff1a<\/p>\n<pre><code>$ numactl --membind 1 --cpunodebind 1 --localalloc myapplication<\/code><\/pre>\n<h5 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u6587\u4ef6\u7cfb\u7edf\u8c03\u4f18\">\u00a0 \u6587\u4ef6\u7cfb\u7edf\u8c03\u4f18<\/h5>\n<h5 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\"><\/h5>\n<p>\u5173\u4e8e\u6587\u4ef6\u7cfb\u7edf\uff0c\u56e0\u4e3a\u6587\u4ef6\u7cfb\u7edf\u4e5f\u662f\u6709 cache \u7684\uff0c\u6240\u4ee5\uff0c\u4e3a\u4e86\u8ba9\u6587\u4ef6\u7cfb\u7edf\u6709\u6700\u5927\u7684\u6027\u80fd\u3002\u9996\u8981\u7684\u4e8b\u60c5\u5c31\u662f\u5206\u914d\u8db3\u591f\u5927\u7684\u5185\u5b58\uff0c\u8fd9\u4e2a\u975e\u5e38\u5173\u952e\uff0c\u5728 Linux \u4e0b\u53ef\u4ee5\u4f7f\u7528 free \u547d\u4ee4\u6765\u67e5\u770b free\/used\/buffers\/cached\uff0c\u7406\u60f3\u6765\u8bf4\uff0cbuffers \u548c cached \u5e94\u8be5\u6709 40% \u5de6\u53f3\u3002\u7136\u540e\u662f\u4e00\u4e2a\u5feb\u901f\u7684\u786c\u76d8\u63a7\u5236\u5668\uff0cSCSI \u4f1a\u597d\u5f88\u591a\u3002\u6700\u5feb\u7684\u662f Intel SSD \u56fa\u6001\u786c\u76d8\uff0c\u901f\u5ea6\u8d85\u5feb\uff0c\u4f46\u662f\u5199\u6b21\u6570\u6709\u9650\u3002<\/p>\n<p>\u63a5\u4e0b\u6765\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u8c03\u4f18\u6587\u4ef6\u7cfb\u7edf\u914d\u7f6e\u4e86\uff0c\u5bf9\u4e8e Linux \u7684 Ext3\/4 \u6765\u8bf4\uff0c\u51e0\u4e4e\u5728\u6240\u6709\u60c5\u51b5\u4e0b\u90fd\u6709\u6240\u5e2e\u52a9\u7684\u4e00\u4e2a\u53c2\u6570\u662f\u5173\u95ed\u6587\u4ef6\u7cfb\u7edf\u8bbf\u95ee\u65f6\u95f4\uff0c\u5728 \/etc\/fstab \u4e0b\u770b\u770b\u4f60\u7684\u6587\u4ef6\u7cfb\u7edf \u6709\u6ca1\u6709 noatime \u53c2\u6570\uff08\u4e00\u822c\u6765\u8bf4\u5e94\u8be5\u6709\uff09\uff0c\u8fd8\u6709\u4e00\u4e2a\u662f dealloc\uff0c\u5b83\u53ef\u4ee5\u8ba9\u7cfb\u7edf\u5728\u6700\u540e\u65f6\u523b\u51b3\u5b9a\u5199\u5165\u6587\u4ef6\u53d1\u751f\u65f6\u4f7f\u7528\u54ea\u4e2a\u5757\uff0c\u53ef\u4f18\u5316\u8fd9\u4e2a\u5199\u5165\u7a0b\u5e8f\u3002\u8fd8\u8981\u6ce8\u95f4\u4e00\u4e0b\u4e09\u79cd\u65e5\u5fd7\u6a21\u5f0f\uff1adata=journal\u3001data=ordered \u548c data=writeback\u3002\u9ed8\u8ba4\u8bbe\u7f6e data=ordered \u63d0\u4f9b\u6027\u80fd\u548c\u9632\u62a4\u4e4b\u95f4\u7684\u6700\u4f73\u5e73\u8861\u3002<\/p>\n<p>\u5f53\u7136\uff0c\u5bf9\u4e8e\u8fd9\u4e9b\u6765\u8bf4\uff0cext4 \u7684\u9ed8\u8ba4\u8bbe\u7f6e\u57fa\u672c\u4e0a\u662f\u6700\u4f73\u4f18\u5316\u4e86\u3002<\/p>\n<p>\u8fd9\u91cc\u4ecb\u7ecd\u4e00\u4e2a Linux \u4e0b\u7684\u67e5\u770b I\/O \u7684\u547d\u4ee4\u2014\u2014 iotop\uff0c\u53ef\u4ee5\u8ba9\u4f60\u770b\u5230\u5404\u8fdb\u7a0b\u7684\u78c1\u76d8\u8bfb\u5199\u7684\u8d1f\u8f7d\u60c5\u51b5\u3002<\/p>\n<p>\u5176\u5b83\u8fd8\u6709\u4e00\u4e9b\u5173\u4e8e NFS\u3001XFS \u7684\u8c03\u4f18\uff0c\u5927\u5bb6\u53ef\u4ee5\u4e0a google \u641c\u7d22\u4e00\u4e9b\u76f8\u5173\u4f18\u5316\u7684\u6587\u7ae0\u770b\u770b\u3002<\/p>\n<h4 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u6570\u636e\u5e93\u8c03\u4f18\">\u6570\u636e\u5e93\u8c03\u4f18<\/h4>\n<p>\u6570\u636e\u5e93\u8c03\u4f18\u5e76\u4e0d\u662f\u6211\u7684\u5f3a\u9879\uff0c\u6211\u5c31\u4ec5\u7528\u6211\u975e\u5e38\u6709\u9650\u7684\u77e5\u8bc6\u8bf4\u4e0a\u4e00\u4e9b\u5427\u3002\u6ce8\u610f\uff0c\u4e0b\u9762\u7684\u8fd9\u4e9b\u4e1c\u897f\u5e76\u4e0d\u4e00\u5b9a\u6b63\u786e\uff0c\u56e0\u4e3a\u5728\u4e0d\u540c\u7684\u4e1a\u52a1\u573a\u666f\uff0c\u4e0d\u540c\u7684\u6570\u636e\u5e93\u8bbe\u8ba1\u4e0b\u53ef\u80fd\u4f1a\u5f97\u5230\u5b8c\u5168\u76f8\u53cd\u7684\u7ed3\u8bba\uff0c\u6240\u4ee5\uff0c\u6211\u4ec5\u5728\u8fd9\u91cc\u505a\u4e00\u4e9b\u4e00\u822c\u6027\u7684\u8bf4\u660e\uff0c\u5177\u4f53\u95ee\u9898\u8fd8\u8981\u5177\u4f53\u5206\u6790\u3002<\/p>\n<h5 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-\u6570\u636e\u5e93\u5f15\u64ce\u8c03\u4f18\">\u00a0\u00a0\u6570\u636e\u5e93\u5f15\u64ce\u8c03\u4f18<\/h5>\n<p>\u6211\u5bf9\u6570\u636e\u5e93\u5f15\u64ce\u4e0d\u662f\u719f\uff0c\u4f46\u662f\u6709\u51e0\u4e2a\u4e8b\u60c5\u6211\u89c9\u5f97\u662f\u4e00\u5b9a\u8981\u53bb\u4e86\u89e3\u7684\u3002<\/p>\n<ul class=\"list-paddingleft-2\">\n<li><strong>\u6570\u636e\u5e93\u7684\u9501\u7684\u65b9\u5f0f<\/strong>\u3002\u8fd9\u4e2a\u975e\u5e38\u975e\u5e38\u5730\u91cd\u8981\u3002\u5e76\u53d1\u60c5\u51b5\u4e0b\uff0c\u9501\u662f\u975e\u5e38\u975e\u5e38\u5f71\u54cd\u6027\u80fd\u7684\u3002\u5404\u79cd\u9694\u79bb\u7ea7\u522b\uff0c\u884c\u9501\uff0c\u8868\u9501\uff0c\u9875\u9501\uff0c\u8bfb\u5199\u9501\uff0c\u4e8b\u52a1\u9501\uff0c\u4ee5\u53ca\u5404\u79cd\u5199\u4f18\u5148\u8fd8\u662f\u8bfb\u4f18\u5148\u673a\u5236\u3002\u6027\u80fd\u6700\u9ad8\u7684\u662f\u4e0d\u8981\u9501\uff0c\u6240\u4ee5\uff0c\u5206\u5e93\u5206\u8868\uff0c\u5197\u4f59\u6570\u636e\uff0c\u51cf\u5c11\u4e00\u81f4\u6027\u4e8b\u52a1\u5904\u7406\uff0c\u53ef\u4ee5\u6709\u6548\u5730\u63d0\u9ad8\u6027\u80fd\u3002NoSQL \u5c31\u662f\u727a\u7272\u4e86\u4e00\u81f4\u6027\u548c\u4e8b\u52a1\u5904\u7406\uff0c\u5e76\u5197\u4f59\u6570\u636e\uff0c\u4ece\u800c\u8fbe\u5230\u4e86\u5206\u5e03\u5f0f\u548c\u9ad8\u6027\u80fd\u3002<\/li>\n<li><strong>\u6570\u636e\u5e93\u7684\u5b58\u50a8\u673a\u5236<\/strong>\u3002\u4e0d\u4f46\u8981\u641e\u6e05\u695a\u5404\u79cd\u7c7b\u578b\u5b57\u6bb5\u662f\u600e\u4e48\u5b58\u50a8\u7684\uff0c\u66f4\u91cd\u8981\u7684\u662f\u6570\u636e\u5e93\u7684\u6570\u636e\u5b58\u50a8\u65b9\u5f0f\uff0c\u662f\u600e\u4e48\u5206\u533a\u7684\uff0c\u662f\u600e\u4e48\u7ba1\u7406\u7684\uff0c\u6bd4\u5982 Oracle \u7684\u6570\u636e\u6587\u4ef6\uff0c\u8868\u7a7a\u95f4\uff0c\u6bb5\uff0c\u7b49\u7b49\u3002\u4e86\u89e3\u6e05\u695a\u8fd9\u4e2a\u673a\u5236\u53ef\u4ee5\u51cf\u8f7b\u5f88\u591a\u7684 I\/O \u8d1f\u8f7d\u3002\u6bd4\u5982\uff1aMySQL \u4e0b\u4f7f\u7528 show engines; \u53ef\u4ee5\u770b\u5230\u5404\u79cd\u5b58\u50a8\u5f15\u64ce\u7684\u652f\u6301\u3002\u4e0d\u540c\u7684\u5b58\u50a8\u5f15\u64ce\u6709\u4e0d\u540c\u7684\u4fa7\u91cd\u70b9\uff0c\u9488\u5bf9\u4e0d\u540c\u7684\u4e1a\u52a1\u6216\u6570\u636e\u5e93\u8bbe\u8ba1\u4f1a\u8ba9\u4f60\u6709\u4e0d\u540c\u7684\u6027\u80fd\u3002<\/li>\n<li><strong>\u6570\u636e\u5e93\u7684\u5206\u5e03\u5f0f\u7b56\u7565<\/strong>\u3002\u6700\u7b80\u5355\u7684\u5c31\u662f\u590d\u5236\u6216\u955c\u50cf\uff0c\u9700\u8981\u4e86\u89e3\u5206\u5e03\u5f0f\u7684\u4e00\u81f4\u6027\u7b97\u6cd5\uff0c\u6216\u662f\u4e3b\u4e3b\u540c\u6b65\uff0c\u4e3b\u4ece\u540c\u6b65\u3002\u901a\u8fc7\u4e86\u89e3\u8fd9\u79cd\u6280\u672f\u7684\u673a\u7406\u53ef\u4ee5\u505a\u5230\u6570\u636e\u5e93\u7ea7\u522b\u7684\u6c34\u5e73\u6269\u5c55\u3002<\/li>\n<\/ul>\n<h5 id=\"id-[collect]\u6027\u80fd\u8c03\u4f18\u653b\u7565-SQL\u8bed\u53e5\u4f18\u5316\">\u00a0\u00a0SQL \u8bed\u53e5\u4f18\u5316<\/h5>\n<p>\u5173\u4e8e SQL \u8bed\u53e5\u7684\u4f18\u5316\uff0c\u9996\u5148\u4e5f\u662f\u8981\u4f7f\u7528\u5de5\u5177\uff0c\u6bd4\u5982\uff1aMySQL SQL Query Analyzer\uff0cOracle SQL Performance Analyzer\uff0c\u6216\u662f\u5fae\u8f6f SQL Query Analyzer\uff0c\u57fa\u672c\u4e0a\u6765\u8bf4\uff0c\u6240\u6709\u7684 RMDB \u90fd\u4f1a\u6709\u8fd9\u6837\u7684\u5de5\u5177\uff0c\u6765\u8ba9\u4f60\u67e5\u770b\u4f60\u7684\u5e94\u7528\u4e2d\u7684 SQL \u7684\u6027\u80fd\u95ee\u9898\u3002 \u8fd8\u53ef\u4ee5\u4f7f\u7528 explain \u6765\u770b\u770b SQL \u8bed\u53e5\u6700\u7ec8 Execution Plan \u4f1a\u662f\u4ec0\u4e48\u6837\u7684\u3002<\/p>\n<p>\u8fd8\u6709\u4e00\u70b9\u5f88\u91cd\u8981\uff0c\u6570\u636e\u5e93\u7684\u5404\u79cd\u64cd\u4f5c\u9700\u8981\u5927\u91cf\u7684\u5185\u5b58\uff0c\u6240\u4ee5\u670d\u52a1\u5668\u7684\u5185\u5b58\u8981\u591f\uff0c\u4f18\u5176\u5e94\u5bf9\u90a3\u4e9b\u591a\u8868\u67e5\u8be2\u7684 SQL \u8bed\u53e5\uff0c\u90a3\u662f\u76f8\u5f53\u7684\u8017\u5185\u5b58\u3002<\/p>\n<p>\u4e0b\u9762\u6211\u6839\u636e\u6211\u6709\u9650\u7684\u6570\u636e\u5e93 SQL \u7684\u77e5\u8bc6\u8bf4\u51e0\u4e2a\u4f1a\u6709\u6027\u80fd\u95ee\u9898\u7684 SQL\uff1a<\/p>\n<p><strong>\u5168\u8868\u68c0\u7d22<\/strong>\u3002\u6bd4\u5982\uff1aselect * from user where lastname = \u201cxxxx\u201d\uff0c\u8fd9\u6837\u7684 SQL \u8bed\u53e5\u57fa\u672c\u4e0a\u662f\u5168\u8868\u67e5\u627e\uff0c\u7ebf\u6027\u590d\u6742\u5ea6 O(n)\uff0c\u8bb0\u5f55\u6570\u8d8a\u591a\uff0c\u6027\u80fd\u4e5f\u8d8a\u5dee\uff08\u5982\uff1a100 \u6761\u8bb0\u5f55\u7684\u67e5\u627e\u8981 50ms\uff0c\u4e00\u767e\u4e07\u6761\u8bb0\u5f55\u9700\u8981 5 \u5206\u949f\uff09\u3002\u5bf9\u4e8e\u8fd9\u79cd\u60c5\u51b5\uff0c\u6211\u4eec\u53ef\u4ee5\u6709\u4e24\u79cd\u65b9\u6cd5\u63d0\u9ad8\u6027\u80fd\uff1a\u4e00\u79cd\u65b9\u6cd5\u662f\u5206\u8868\uff0c\u628a\u8bb0\u5f55\u6570\u964d\u4e0b\u6765\uff0c\u53e6\u4e00\u79cd\u65b9\u6cd5\u662f\u5efa\u7d22\u5f15\uff08\u4e3a lastname \u5efa\u7d22\u5f15\uff09\u3002\u7d22\u5f15\u5c31\u50cf\u662f key-value \u7684\u6570\u636e\u7ed3\u6784\u4e00\u6837\uff0ckey \u5c31\u662f where \u540e\u9762\u7684\u5b57\u6bb5\uff0cvalue \u5c31\u662f\u7269\u7406\u884c\u53f7\uff0c\u5bf9\u7d22\u5f15\u7684\u641c\u7d22\u590d\u6742\u5ea6\u662f\u57fa\u672c\u4e0a\u662f O(log(n)) \u2014\u2014\u7528 B-Tree \u5b9e\u73b0\u7d22\u5f15\uff08\u5982\uff1a100 \u6761\u8bb0\u5f55\u7684\u67e5\u627e\u8981 50ms\uff0c\u4e00\u767e\u4e07\u6761\u8bb0\u5f55\u9700\u8981 100ms\uff09\u3002<\/p>\n<p><strong>\u7d22\u5f15<\/strong>\u3002\u5bf9\u4e8e\u7d22\u5f15\u5b57\u6bb5\uff0c\u6700\u597d\u4e0d\u8981\u5728\u5b57\u6bb5\u4e0a\u505a\u8ba1\u7b97\u3001\u7c7b\u578b\u8f6c\u6362\u3001\u51fd\u6570\u3001\u7a7a\u503c\u5224\u65ad\u3001\u5b57\u6bb5\u8fde\u63a5\u64cd\u4f5c\uff0c\u8fd9\u4e9b\u64cd\u4f5c\u90fd\u4f1a\u7834\u574f\u7d22\u5f15\u539f\u672c\u7684\u6027\u80fd\u3002\u5f53\u7136\uff0c\u7d22\u5f15\u4e00\u822c\u90fd\u51fa\u73b0\u5728 Where \u6216\u662f Order by \u5b57\u53e5\u4e2d\uff0c\u6240\u4ee5\u5bf9 Where \u548c Order by \u5b50\u53e5\u4e2d\u7684\u5b50\u6bb5\u6700\u597d\u4e0d\u8981\u8fdb\u884c\u8ba1\u7b97\u64cd\u4f5c\uff0c\u6216\u662f\u52a0\u4e0a\u4ec0\u4e48 NOT \u4e4b\u7c7b\u7684\uff0c\u6216\u662f\u4f7f\u7528\u4ec0\u4e48\u51fd\u6570\u3002<\/p>\n<p><strong>\u591a\u8868\u67e5\u8be2<\/strong>\u3002\u5173\u7cfb\u578b\u6570\u636e\u5e93\u6700\u591a\u7684\u64cd\u4f5c\u5c31\u662f\u591a\u8868\u67e5\u8be2\uff0c\u591a\u8868\u67e5\u8be2\u4e3b\u8981\u6709\u4e09\u4e2a\u5173\u952e\u5b57\uff0cEXISTS\uff0cIN \u548c JOIN\uff08\u5173\u4e8e\u5404\u79cd join\uff0c\u53ef\u4ee5\u53c2\u770b\u56fe\u89e3 SQL \u7684 Join \u4e00\u6587\uff09\u3002\u57fa\u672c\u6765\u8bf4\uff0c\u73b0\u4ee3\u7684\u6570\u636e\u5f15\u64ce\u5bf9 SQL \u8bed\u53e5\u4f18\u5316\u5f97\u90fd\u633a\u597d\u7684\uff0cJOIN \u548c IN\/EXISTS \u5728\u7ed3\u679c\u4e0a\u6709\u4e9b\u4e0d\u540c\uff0c\u4f46\u6027\u80fd\u57fa\u672c\u4e0a\u90fd\u5dee\u4e0d\u591a\u3002\u6709\u4eba\u8bf4\uff0cEXISTS \u7684\u6027\u80fd\u8981\u597d\u4e8e IN\uff0cIN \u7684\u6027\u80fd\u8981\u597d\u4e8e JOIN\uff0c\u6211\u5404\u4eba\u89c9\u5f97\uff0c\u8fd9\u4e2a\u8fd8\u8981\u770b\u4f60\u7684\u6570\u636e\u3001schema \u548c SQL \u8bed\u53e5\u7684\u590d\u6742\u5ea6\uff0c\u5bf9\u4e8e\u4e00\u822c\u7684\u7b80\u5355\u7684\u60c5\u51b5\u6765\u8bf4\uff0c\u90fd\u5dee\u4e0d\u591a\uff0c\u6240\u4ee5\u5343\u4e07\u4e0d\u8981\u4f7f\u7528\u8fc7\u591a\u7684\u5d4c\u5957\uff0c\u5343\u4e07\u4e0d\u8981\u8ba9\u4f60\u7684 SQL \u592a\u590d\u6742\uff0c\u5b81\u53ef\u4f7f\u7528\u51e0\u4e2a\u7b80\u5355\u7684 SQL \u4e5f\u4e0d\u8981\u4f7f\u7528\u4e00\u4e2a\u5de8\u5927\u65e0\u6bd4\u7684\u5d4c\u5957 N \u7ea7\u7684 SQL\u3002<\/p>\n<p>\u8fd8\u6709\u4eba\u8bf4\uff0c\u5982\u679c\u4e24\u4e2a\u8868\u7684\u6570\u636e\u91cf\u5dee\u4e0d\u591a\uff0cExists \u7684\u6027\u80fd\u53ef\u80fd\u4f1a\u9ad8\u4e8e In\uff0cIn \u53ef\u80fd\u4f1a\u9ad8\u4e8e Join\uff0c\u5982\u679c\u8fd9\u4e24\u4e2a\u8868\u4e00\u5927\u4e00\u5c0f\uff0c\u90a3\u4e48\u5b50\u67e5\u8be2\u4e2d\uff0cExists \u7528\u5927\u8868\uff0cIn \u5219\u7528\u5c0f\u8868\u3002\u8fd9\u4e2a\uff0c\u6211\u6ca1\u6709\u9a8c\u8bc1\u8fc7\uff0c\u653e\u5728\u8fd9\u91cc\u8ba9\u5927\u5bb6\u8ba8\u8bba\u5427\u3002\u53e6\uff0c\u6709\u4e00\u7bc7\u5173\u4e8e SQL Server \u7684\u6587\u7ae0\u5927\u5bb6\u53ef\u4ee5\u770b\u770b\u300aIN vs JOIN vs EXISTS\u300b<\/p>\n<p><strong>JOIN \u64cd\u4f5c<\/strong>\u3002\u6709\u4eba\u8bf4\uff0cJoin \u8868\u7684\u987a\u5e8f\u4f1a\u5f71\u54cd\u6027\u80fd\uff0c\u53ea\u8981 Join \u7684\u7ed3\u679c\u96c6\u662f\u4e00\u6837\uff0c\u6027\u80fd\u548c join \u7684\u6b21\u5e8f\u65e0\u5173\u3002\u56e0\u4e3a\u540e\u53f0\u7684\u6570\u636e\u5e93\u5f15\u64ce\u4f1a\u5e2e\u6211\u4eec\u4f18\u5316\u7684\u3002Join \u6709\u4e09\u79cd\u5b9e\u73b0\u7b97\u6cd5\uff0c\u5d4c\u5957\u5faa\u73af\uff0c\u6392\u5e8f\u5f52\u5e76\uff0c\u548c Hash \u5f0f\u7684 Join\u3002\uff08MySQL \u53ea\u652f\u6301\u7b2c\u4e00\u79cd\uff09<\/p>\n<ul class=\"list-paddingleft-2\">\n<li>\u5d4c\u5957\u5faa\u73af\uff0c\u5c31\u597d\u50cf\u662f\u6211\u4eec\u5e38\u89c1\u7684\u591a\u91cd\u5d4c\u5957\u5faa\u73af\u3002\u6ce8\u610f\uff0c\u524d\u9762\u7684\u7d22\u5f15\u8bf4\u8fc7\uff0c\u6570\u636e\u5e93\u7684\u7d22\u5f15\u67e5\u627e\u7b97\u6cd5\u7528\u7684\u662f B-Tree\uff0c\u8fd9\u662f O(log(n)) \u7684\u7b97\u6cd5\uff0c\u6240\u4ee5\uff0c\u6574\u4e2a\u7b97\u6cd5\u590d\u6cd5\u5ea6\u5e94\u8be5\u662f O(log(n)) * O(log(m)) \u8fd9\u6837\u7684\u3002<\/li>\n<li>Hash \u5f0f\u7684 Join\uff0c\u4e3b\u8981\u89e3\u51b3\u5d4c\u5957\u5faa\u73af\u7684 O(log(n)) \u7684\u590d\u6742\uff0c\u4f7f\u7528\u4e00\u4e2a\u4e34\u65f6\u7684 hash \u8868\u6765\u6807\u8bb0\u3002<\/li>\n<li>\u6392\u5e8f\u5f52\u5e76\uff0c\u610f\u601d\u662f\u4e24\u4e2a\u8868\u6309\u7167\u67e5\u8be2\u5b57\u6bb5\u6392\u597d\u5e8f\uff0c\u7136\u540e\u518d\u5408\u5e76\u3002\u5f53\u7136\uff0c\u7d22\u5f15\u5b57\u6bb5\u4e00\u822c\u662f\u6392\u597d\u5e8f\u7684\u3002<\/li>\n<\/ul>\n<p>\u8fd8\u662f\u90a3\u53e5\u8bdd\uff0c\u5177\u4f53\u8981\u770b\u4ec0\u4e48\u6837\u7684\u6570\u636e\uff0c\u4ec0\u4e48\u6837\u7684 SQL \u8bed\u53e5\uff0c\u4f60\u624d\u77e5\u9053\u7528\u54ea\u79cd\u65b9\u6cd5\u662f\u6700\u597d\u7684\u3002<\/p>\n<p><strong>\u90e8\u5206\u7ed3\u679c\u96c6<\/strong>\u3002\u6211\u4eec\u77e5\u9053 MySQL \u91cc\u7684 Limit \u5173\u952e\u5b57\uff0cOracle \u91cc\u7684 rownum\uff0cSQL Server \u91cc\u7684 Top \u90fd\u662f\u5728\u9650\u5236\u524d\u51e0\u6761\u7684\u8fd4\u56de\u7ed3\u679c\u3002\u8fd9\u7ed9\u4e86\u6211\u4eec\u6570\u636e\u5e93\u5f15\u64ce\u5f88\u591a\u53ef\u4ee5\u8c03\u4f18\u7684\u7a7a\u95f4\u3002\u4e00\u822c\u6765\u8bf4\uff0c\u8fd4\u56de top n \u7684\u8bb0\u5f55\u6570\u636e\u9700\u8981\u6211\u4eec\u4f7f\u7528 order by\uff0c\u6ce8\u610f\u5728\u8fd9\u91cc\u6211\u4eec\u9700\u8981\u4e3a order by \u7684\u5b57\u6bb5\u5efa\u7acb\u7d22\u5f15\u3002\u6709\u4e86\u88ab\u5efa\u7d22\u5f15\u7684 order by \u540e\uff0c\u4f1a\u8ba9\u6211\u4eec\u7684 select \u8bed\u53e5\u7684\u6027\u80fd\u4e0d\u4f1a\u88ab\u8bb0\u5f55\u6570\u7684\u6240\u5f71\u54cd\u3002\u4f7f\u7528\u8fd9\u4e2a\u6280\u672f\uff0c\u4e00\u822c\u6765\u8bf4\u6211\u4eec\u524d\u53f0\u4f1a\u4ee5\u5206\u9875\u65b9\u5f0f\u6765\u663e\u73b0\u6570\u636e\uff0cMysql \u7528\u7684\u662f OFFSET\uff0cSQL Server \u7528\u7684\u662f FETCH NEXT\uff0c\u8fd9\u79cd Fetch \u7684\u65b9\u5f0f\u5176\u5b9e\u5e76\u4e0d\u597d\u662f\u7ebf\u6027\u590d\u6742\u5ea6\uff0c\u6240\u4ee5\uff0c\u5982\u679c\u6211\u4eec\u80fd\u591f\u77e5\u9053 order by \u5b57\u6bb5\u7684\u7b2c\u4e8c\u9875\u7684\u8d77\u59cb\u503c\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u5728 where \u8bed\u53e5\u91cc\u76f4\u63a5\u4f7f\u7528&gt;= \u7684\u8868\u8fbe\u5f0f\u6765 select\uff0c\u8fd9\u79cd\u6280\u672f\u53eb seek\uff0c\u800c\u4e0d\u662f fetch\uff0cseek \u7684\u6027\u80fd\u6bd4 fetch \u8981\u9ad8\u5f88\u591a\u3002<\/p>\n<p><strong>\u5b57\u7b26\u4e32<\/strong>\u3002\u6b63\u5982\u6211\u524d\u9762\u6240\u8bf4\u7684\uff0c\u5b57\u7b26\u4e32\u64cd\u4f5c\u5bf9\u6027\u80fd\u4e0a\u6709\u975e\u5e38\u5927\u7684\u6076\u68a6\uff0c\u6240\u4ee5\uff0c\u80fd\u7528\u6570\u636e\u7684\u60c5\u51b5\u5c31\u7528\u6570\u5b57\uff0c\u6bd4\u5982\uff1a\u65f6\u95f4\uff0c\u5de5\u53f7\uff0c\u7b49\u3002<\/p>\n<p><strong>\u5168\u6587\u68c0\u7d22<\/strong>\u3002\u5343\u4e07\u4e0d\u8981\u7528 Like \u4e4b\u7c7b\u7684\u4e1c\u897f\u6765\u505a\u5168\u6587\u68c0\u7d22\uff0c\u5982\u679c\u8981\u73a9\u5168\u6587\u68c0\u7d22\uff0c\u53ef\u4ee5\u5c1d\u8bd5\u4f7f\u7528 Sphinx\u3002<\/p>\n<p>\u5176\u5b83\u3002<\/p>\n<ul class=\"list-paddingleft-2\">\n<li>\u4e0d\u8981 select *\uff0c\u800c\u662f\u660e\u786e\u6307\u51fa\u5404\u4e2a\u5b57\u6bb5\uff0c\u5982\u679c\u6709\u591a\u4e2a\u8868\uff0c\u4e00\u5b9a\u8981\u5728\u5b57\u6bb5\u540d\u524d\u52a0\u4e0a\u8868\u540d\uff0c\u4e0d\u8981\u8ba9\u5f15\u64ce\u53bb\u7b97\u3002<\/li>\n<li>\u4e0d\u8981\u7528 Having\uff0c\u56e0\u4e3a\u5176\u8981\u904d\u5386\u6240\u6709\u7684\u8bb0\u5f55\u3002\u6027\u80fd\u5dee\u5f97\u4e0d\u80fd\u518d\u5dee\u3002<\/li>\n<li>\u5c3d\u53ef\u80fd\u5730\u4f7f\u7528 UNION ALL \u00a0\u53d6\u4ee3 \u00a0UNION\u3002<\/li>\n<li>\u7d22\u5f15\u8fc7\u591a\uff0cinsert \u548c delete \u5c31\u4f1a\u8d8a\u6162\u3002\u800c update \u5982\u679c update \u591a\u6570\u7d22\u5f15\uff0c\u4e5f\u4f1a\u6162\uff0c\u4f46\u662f\u5982\u679c\u53ea update \u4e00\u4e2a\uff0c\u5219\u53ea\u4f1a\u5f71\u54cd\u4e00\u4e2a\u7d22\u5f15\u8868\u3002<\/li>\n<li>\u7b49\u7b49\u3002<\/li>\n<\/ul>\n<p>\u5173\u4e8eSQL\u8bed\u53e5\u7684\u4f18\u5316\uff0c\u7f51\u4e0a\u6709\u5f88\u591a\u6587\u7ae0\uff0c \u4e0d\u540c\u7684\u6570\u636e\u5e93\u5f15\u64ce\u6709\u4e0d\u540c\u7684\u4f18\u5316\u6280\u5de7\uff0c\u6b63\u5982\u672c\u7ad9\u4ee5\u524d\u8f6c\u53d1\u7684\u300a<a class=\"external-link\" href=\"http:\/\/coolshell.cn\/articles\/1846.html\" rel=\"nofollow\">MySQL\u6027\u80fd\u4f18\u5316\u7684\u6700\u4f7320+\u6761\u7ecf\u9a8c<\/a>\u300b<\/p>\n<p>\u5148\u5199\u8fd9\u4e48\u591a\u5427\uff0c\u6b22\u8fce\u5927\u5bb6\u6307\u6b63\u8865\u5145\u3002<\/p>\n<blockquote><p><strong>\u6ce8\uff1a<\/strong>\u8fd9\u7bc7\u6587\u7ae0\u7684\u786e\u662f\u4e2a\u5927\u6742\u70e9\u3002\u5176\u5b9e\u5176\u4e2d\u7684\u8bf4\u5230\u7684\u5f88\u591a\u6280\u672f\u5728\u7f51\u4e0a\u90fd\u6709\u5f88\u591a\u5f88\u591a\u7684\u6280\u672f\u6587\u7ae0\uff0cgoogle\u4e00\u4e0b\u5c31\u80fd\u627e\u5230\u4e00\u5806\u6709\u5f88\u591a\u7ec6\u8282\u7684\u6587\u7ae0\uff0c\u6240\u4ee5\u6211\u4e5f\u5c31\u4e0d\u5199\u4e86\u3002\u8fd9\u7bc7\u6027\u80fd\u8c03\u4f18\u7684\u6587\u7ae0\u5199\u4f5c\u7684\u52a8\u673a\u662f\u4e4b\u524d\u770b\u5230\u00a0<a class=\"external-link\" href=\"http:\/\/weibo.com\/n\/%E6%B7%98%E5%AE%9D%E8%A4%9A%E9%9C%B8\" rel=\"nofollow\">@\u6dd8\u5b9d\u891a\u9738<\/a>\u00a0\u5f3a\u63a8\u7684<a class=\"external-link\" href=\"http:\/\/highscalability.com\/\" rel=\"nofollow\">highscalability.com<\/a>\u4e0a\u7684\u8fd9\u7bc7\u6587\u7ae0\uff1a<a class=\"external-link\" href=\"http:\/\/highscalability.com\/blog\/2012\/5\/16\/big-list-of-20-common-bottlenecks.html\" rel=\"nofollow\">Big List Of 20 Common Bottlenecks<\/a>\uff0c\u89c9\u5f97\u8fd9\u7bc7\u6587\u7ae0\u6cdb\u6cdb\u800c\u8c08\uff0c\u89c9\u5f97\u81ea\u5df1\u80fd\u5199\u5f97\u6bd4\u5b83\u597d\uff0c\u6240\u4ee5\u5c31\u4ea7\u751f\u4e86\u52a8\u673a\u3002<\/p><\/blockquote>\n<p>=END=<\/p>\n","protected":false},"excerpt":{"rendered":"<p>=Start= \u7f18\u7531\uff1a \u672c\u6587\u662f\u9177\u58f3\u535a\u4e3b\u9648\u7693\u51e0\u5e74\u524d(2012\u5e7406\u670820\u65e5)\u5199\u7684\u300c\u6027\u80fd\u8c03\u4f18\u653b\u7565\u300d\uff0c\u65f6\u9694\u591a\u5e74\u518d\u770b\uff0c [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23,7],"tags":[811,810,809,812,813],"class_list":["post-3343","post","type-post","status-publish","format-standard","hentry","category-knowledgebase-2","category-programing","tag-coolshell","tag-latency","tag-throughput","tag-812","tag-813"],"views":14952,"_links":{"self":[{"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/posts\/3343","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/comments?post=3343"}],"version-history":[{"count":1,"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/posts\/3343\/revisions"}],"predecessor-version":[{"id":3345,"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/posts\/3343\/revisions\/3345"}],"wp:attachment":[{"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/media?parent=3343"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/categories?post=3343"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/tags?post=3343"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}