{"id":128345,"date":"2024-10-26T13:28:18","date_gmt":"2024-10-26T05:28:18","guid":{"rendered":"https:\/\/server.hk\/cnblog\/128345\/"},"modified":"2024-10-26T13:28:18","modified_gmt":"2024-10-26T05:28:18","slug":"redis-%e5%af%a6%e7%8f%be%e7%9a%84%e9%ab%98%e6%95%88%e6%b3%8a%e6%9d%be%e5%88%86%e5%b8%83","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/128345\/","title":{"rendered":"Redis \u5be6\u73fe\u7684\u9ad8\u6548\u6cca\u677e\u5206\u5e03"},"content":{"rendered":"<h1 id=\"redis-%e5%af%a6%e7%8f%be%e7%9a%84%e9%ab%98%e6%95%88%e6%b3%8a%e6%9d%be%e5%88%86%e5%b8%83-qbwyLPxuUp\">Redis \u5be6\u73fe\u7684\u9ad8\u6548\u6cca\u677e\u5206\u5e03<\/h1>\n<p>\u6cca\u677e\u5206\u5e03\u662f\u4e00\u7a2e\u5e38\u898b\u7684\u6982\u7387\u5206\u5e03\uff0c\u901a\u5e38\u7528\u65bc\u63cf\u8ff0\u5728\u56fa\u5b9a\u6642\u9593\u5167\u67d0\u4e8b\u4ef6\u767c\u751f\u7684\u6b21\u6578\u3002\u5b83\u5728\u8a31\u591a\u9818\u57df\u4e2d\u90fd\u6709\u61c9\u7528\uff0c\u5305\u62ec\u6392\u968a\u7406\u8ad6\u3001\u96fb\u4fe1\u3001\u4ea4\u901a\u6d41\u91cf\u5206\u6790\u7b49\u3002\u96a8\u8457\u5927\u6578\u64da\u548c\u5be6\u6642\u6578\u64da\u8655\u7406\u7684\u9700\u6c42\u589e\u52a0\uff0cRedis \u4f5c\u70ba\u4e00\u500b\u9ad8\u6548\u7684\u6578\u64da\u7d50\u69cb\u4f3a\u670d\u5668\uff0c\u63d0\u4f9b\u4e86\u5be6\u73fe\u6cca\u677e\u5206\u5e03\u7684\u7406\u60f3\u5e73\u53f0\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af%e6%b3%8a%e6%9d%be%e5%88%86%e5%b8%83%ef%bc%9f-qbwyLPxuUp\">\u4ec0\u9ebc\u662f\u6cca\u677e\u5206\u5e03\uff1f<\/h2>\n<p>\u6cca\u677e\u5206\u5e03\u662f\u4e00\u7a2e\u96e2\u6563\u6982\u7387\u5206\u5e03\uff0c\u63cf\u8ff0\u5728\u56fa\u5b9a\u6642\u9593\u5167\u67d0\u4e8b\u4ef6\u767c\u751f\u7684\u6b21\u6578\u3002\u5176\u6982\u7387\u8cea\u91cf\u51fd\u6578\u70ba\uff1a<\/p>\n<pre><code>P(X = k) = (\u03bb^k * e^(-\u03bb)) \/ k!<\/code><\/pre>\n<p>\u5176\u4e2d\uff0c\u03bb\uff08lambda\uff09\u662f\u4e8b\u4ef6\u7684\u5e73\u5747\u767c\u751f\u7387\uff0ck \u662f\u4e8b\u4ef6\u767c\u751f\u7684\u6b21\u6578\uff0ce \u662f\u81ea\u7136\u5c0d\u6578\u7684\u5e95\u6578\u3002\u6cca\u677e\u5206\u5e03\u7684\u7279\u9ede\u662f\u5b83\u53ea\u4f9d\u8cf4\u65bc\u5e73\u5747\u767c\u751f\u7387 \u03bb\uff0c\u4e26\u4e14\u9069\u7528\u65bc\u4e8b\u4ef6\u7368\u7acb\u4e14\u96a8\u6a5f\u7684\u60c5\u6cc1\u3002<\/p>\n<h2 id=\"redis-%e7%9a%84%e7%89%b9%e6%80%a7-qbwyLPxuUp\">Redis \u7684\u7279\u6027<\/h2>\n<p>Redis \u662f\u4e00\u500b\u958b\u6e90\u7684\u9ad8\u6027\u80fd\u9375\u503c\u6578\u64da\u5eab\uff0c\u652f\u6301\u591a\u7a2e\u6578\u64da\u7d50\u69cb\uff0c\u5982\u5b57\u7b26\u4e32\u3001\u54c8\u5e0c\u3001\u5217\u8868\u3001\u96c6\u5408\u7b49\u3002\u5176\u4e3b\u8981\u7279\u6027\u5305\u62ec\uff1a<\/p>\n<ul>\n<li>\u9ad8\u6548\u7684\u6578\u64da\u5b58\u53d6\u901f\u5ea6<\/li>\n<li>\u652f\u6301\u6301\u4e45\u5316\u6578\u64da<\/li>\n<li>\u652f\u6301\u5206\u4f48\u5f0f\u67b6\u69cb<\/li>\n<li>\u8c50\u5bcc\u7684\u6578\u64da\u7d50\u69cb<\/li>\n<\/ul>\n<p>\u9019\u4e9b\u7279\u6027\u4f7f\u5f97 Redis \u6210\u70ba\u5be6\u73fe\u6cca\u677e\u5206\u5e03\u7684\u7406\u60f3\u9078\u64c7\uff0c\u7279\u5225\u662f\u5728\u9700\u8981\u9ad8\u6548\u6578\u64da\u5b58\u53d6\u548c\u5be6\u6642\u8a08\u7b97\u7684\u5834\u666f\u4e2d\u3002<\/p>\n<h2 id=\"%e5%a6%82%e4%bd%95%e5%9c%a8-redis-%e4%b8%ad%e5%af%a6%e7%8f%be%e6%b3%8a%e6%9d%be%e5%88%86%e5%b8%83-qbwyLPxuUp\">\u5982\u4f55\u5728 Redis \u4e2d\u5be6\u73fe\u6cca\u677e\u5206\u5e03<\/h2>\n<p>\u5728 Redis \u4e2d\u5be6\u73fe\u6cca\u677e\u5206\u5e03\u7684\u904e\u7a0b\u53ef\u4ee5\u5206\u70ba\u4ee5\u4e0b\u5e7e\u500b\u6b65\u9a5f\uff1a<\/p>\n<h3 id=\"1-%e8%a8%ad%e5%ae%9a%e5%b9%b3%e5%9d%87%e7%99%bc%e7%94%9f%e7%8e%87-%ce%bb-qbwyLPxuUp\">1. \u8a2d\u5b9a\u5e73\u5747\u767c\u751f\u7387 \u03bb<\/h3>\n<p>\u9996\u5148\uff0c\u6211\u5011\u9700\u8981\u8a2d\u5b9a\u4e8b\u4ef6\u7684\u5e73\u5747\u767c\u751f\u7387 \u03bb\u3002\u9019\u53ef\u4ee5\u901a\u904e Redis \u7684\u9375\u503c\u5b58\u5132\u4f86\u5be6\u73fe\uff1a<\/p>\n<pre><code>SET average_rate 5<\/code><\/pre>\n<h3 id=\"2-%e9%9a%a8%e6%a9%9f%e7%94%9f%e6%88%90%e4%ba%8b%e4%bb%b6%e6%ac%a1%e6%95%b8-qbwyLPxuUp\">2. \u96a8\u6a5f\u751f\u6210\u4e8b\u4ef6\u6b21\u6578<\/h3>\n<p>\u63a5\u4e0b\u4f86\uff0c\u6211\u5011\u53ef\u4ee5\u4f7f\u7528 Redis \u7684 Lua \u8173\u672c\u4f86\u96a8\u6a5f\u751f\u6210\u4e8b\u4ef6\u7684\u6b21\u6578 k\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u7c21\u55ae\u7684 Lua \u8173\u672c\u793a\u4f8b\uff1a<\/p>\n<pre><code>\nlocal lambda = tonumber(redis.call('GET', 'average_rate'))\nlocal k = 0\nlocal p = math.exp(-lambda)\nlocal sum = p\nlocal u = math.random()\n\nwhile u &gt; sum do\n    k = k + 1\n    p = p * lambda \/ k\n    sum = sum + p\nend\n\nreturn k\n<\/code><\/pre>\n<p>\u9019\u6bb5\u8173\u672c\u4f7f\u7528\u4e86\u6cca\u677e\u5206\u5e03\u7684\u9006\u8b8a\u63db\u62bd\u6a23\u65b9\u6cd5\uff0c\u96a8\u6a5f\u751f\u6210\u4e8b\u4ef6\u6b21\u6578 k\u3002<\/p>\n<h3 id=\"3-%e5%84%b2%e5%ad%98%e5%92%8c%e6%9f%a5%e8%a9%a2%e4%ba%8b%e4%bb%b6%e6%ac%a1%e6%95%b8-qbwyLPxuUp\">3. \u5132\u5b58\u548c\u67e5\u8a62\u4e8b\u4ef6\u6b21\u6578<\/h3>\n<p>\u6700\u5f8c\uff0c\u6211\u5011\u53ef\u4ee5\u5c07\u751f\u6210\u7684\u4e8b\u4ef6\u6b21\u6578\u5b58\u5132\u5230 Redis \u4e2d\uff0c\u4e26\u6839\u64da\u9700\u8981\u9032\u884c\u67e5\u8a62\uff1a<\/p>\n<pre><code>INCR event_count<\/code><\/pre>\n<p>\u9019\u6a23\uff0c\u6211\u5011\u5c31\u53ef\u4ee5\u5728 Redis \u4e2d\u9ad8\u6548\u5730\u5be6\u73fe\u6cca\u677e\u5206\u5e03\uff0c\u4e26\u96a8\u6642\u67e5\u8a62\u4e8b\u4ef6\u7684\u767c\u751f\u6b21\u6578\u3002<\/p>\n<h2 id=\"%e6%87%89%e7%94%a8%e5%a0%b4%e6%99%af-qbwyLPxuUp\">\u61c9\u7528\u5834\u666f<\/h2>\n<p>\u6cca\u677e\u5206\u5e03\u5728\u8a31\u591a\u5be6\u969b\u61c9\u7528\u4e2d\u90fd\u975e\u5e38\u91cd\u8981\u3002\u4f8b\u5982\uff0c\u5728\u7db2\u7d61\u6d41\u91cf\u5206\u6790\u4e2d\uff0c\u53ef\u4ee5\u7528\u4f86\u9810\u6e2c\u5728\u7279\u5b9a\u6642\u9593\u5167\u7684\u8acb\u6c42\u6578\u91cf\uff1b\u5728\u5ba2\u6236\u670d\u52d9\u4e2d\uff0c\u53ef\u4ee5\u7528\u4f86\u9810\u6e2c\u5728\u9ad8\u5cf0\u6642\u6bb5\u7684\u4f86\u96fb\u6578\u91cf\u3002\u4f7f\u7528 Redis \u5be6\u73fe\u6cca\u677e\u5206\u5e03\uff0c\u53ef\u4ee5\u5927\u5e45\u63d0\u9ad8\u8a08\u7b97\u6548\u7387\uff0c\u4e26\u652f\u6301\u5be6\u6642\u6578\u64da\u5206\u6790\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-qbwyLPxuUp\">\u7e3d\u7d50<\/h2>\n<p>\u900f\u904e Redis \u7684\u9ad8\u6548\u6578\u64da\u5b58\u53d6\u80fd\u529b\uff0c\u6211\u5011\u53ef\u4ee5\u8f15\u9b06\u5be6\u73fe\u6cca\u677e\u5206\u5e03\uff0c\u4e26\u61c9\u7528\u65bc\u5404\u7a2e\u5be6\u969b\u5834\u666f\u4e2d\u3002\u7121\u8ad6\u662f\u5728\u7db2\u7d61\u6d41\u91cf\u5206\u6790\u9084\u662f\u5ba2\u6236\u670d\u52d9\u9810\u6e2c\u4e2d\uff0cRedis \u90fd\u80fd\u63d0\u4f9b\u5f37\u5927\u7684\u652f\u6301\u3002\u5982\u679c\u60a8\u5c0d\u65bc\u5982\u4f55\u5728\u9ad8\u6548\u7684\u74b0\u5883\u4e2d\u904b\u884c\u61c9\u7528\u7a0b\u5e8f\u611f\u8208\u8da3\uff0c\u8003\u616e\u4f7f\u7528 <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u4f86\u63d0\u5347\u60a8\u7684\u670d\u52d9\u6027\u80fd\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22Redis\u5be6\u73fe\u7684\u9ad8\u6548\u6cca\u677e\u5206\u5e03\uff0c\u63d0\u5347\u6578\u64da\u8655\u7406\u6027\u80fd\uff0c\u512a\u5316\u96a8\u6a5f\u4e8b\u4ef6\u6a21\u64ec\uff0c\u52a9\u529b\u9ad8\u6548\u8a08\u7b97\u8207\u5206\u6790\u3002<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-128345","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/128345","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=128345"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/128345\/revisions"}],"predecessor-version":[{"id":128346,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/128345\/revisions\/128346"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=128345"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=128345"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=128345"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}