{"id":202176,"date":"2025-05-10T08:36:12","date_gmt":"2025-05-10T00:36:12","guid":{"rendered":"https:\/\/server.hk\/cnblog\/202176\/"},"modified":"2025-05-10T08:36:12","modified_gmt":"2025-05-10T00:36:12","slug":"redis%e4%b8%ad%e8%bf%87%e6%9c%9f%e6%93%8d%e4%bd%9c%e5%92%8c%e8%bf%87%e6%9c%9f%e7%ad%96%e7%95%a5%e7%9a%84%e7%a4%ba%e4%be%8b%e5%88%86%e6%9e%90","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/202176\/","title":{"rendered":"Redis\u4e2d\u8fc7\u671f\u64cd\u4f5c\u548c\u8fc7\u671f\u7b56\u7565\u7684\u793a\u4f8b\u5206\u6790"},"content":{"rendered":"

<\/b> <\/p>\n

Redis\u4e2d\u8fc7\u671f\u64cd\u4f5c\u548c\u8fc7\u671f\u7b56\u7565\u7684\u793a\u4f8b\u5206\u6790<\/h1>\n

<\/i>\u6536\u85cf<\/span> <\/p>\n

\u6570\u636e\u5e93\u5c0f\u767d\u4e00\u679a\uff0c\u6b63\u5728\u4e0d\u65ad\u5b66\u4e60\u79ef\u7d2f\u77e5\u8bc6\uff0c\u73b0\u5c06\u5b66\u4e60\u5230\u7684\u77e5\u8bc6\u8bb0\u5f55\u4e00\u4e0b\uff0c\u4e5f\u662f\u5c06\u6211\u7684\u6240\u5f97\u5206\u4eab\u7ed9\u5927\u5bb6\uff01\u800c\u4eca\u5929\u8fd9\u7bc7\u6587\u7ae0\u300aRedis\u4e2d\u8fc7\u671f\u64cd\u4f5c\u548c\u8fc7\u671f\u7b56\u7565\u7684\u793a\u4f8b\u5206\u6790\u300b\u5e26\u5927\u5bb6\u6765\u4e86\u89e3\u4e00\u4e0b##content_title##\uff0c\u5e0c\u671b\u5bf9\u5927\u5bb6\u7684\u77e5\u8bc6\u79ef\u7d2f\u6709\u6240\u5e2e\u52a9\uff0c\u4ece\u800c\u5f25\u8865\u81ea\u5df1\u7684\u4e0d\u8db3\uff0c\u52a9\u529b\u5b9e\u6218\u5f00\u53d1\uff01<\/p>\n

<\/p>\n

\u8fc7\u671f\u64cd\u4f5c<\/h3>\n

\u8fc7\u671f\u8bbe\u7f6e<\/strong><\/p>\n

Redis<\/code> \u4e2d\u8bbe\u7f6e\u8fc7\u671f\u65f6\u95f4\u4e3b\u8981\u901a\u8fc7\u4ee5\u4e0b\u56db\u79cd\u65b9\u5f0f\uff1a<\/p>\n

    \n
  • \n

    expire key seconds<\/code>\uff1a\u8bbe\u7f6e key<\/code> \u5728 n \u79d2\u540e\u8fc7\u671f\u3002<\/p>\n<\/li>\n

  • \n

    pexpire key milliseconds<\/code>\uff1a\u8bbe\u7f6e key<\/code> \u5728 n \u6beb\u79d2\u540e\u8fc7\u671f\u3002<\/p>\n<\/li>\n

  • \n

    expireat key timestamp<\/code>\uff1a\u8bbe\u7f6e key<\/code> \u5728\u67d0\u4e2a\u65f6\u95f4\u6233\uff08\u7cbe\u786e\u5230\u79d2\uff09\u4e4b\u540e\u8fc7\u671f\u3002<\/p>\n<\/li>\n

  • \n

    pexpireat key millisecondsTimestamp<\/code>\uff1a\u8bbe\u7f6e key<\/code> \u5728\u67d0\u4e2a\u65f6\u95f4\u6233\uff08\u7cbe\u786e\u5230\u6beb\u79d2\uff09\u4e4b\u540e\u8fc7\u671f\u3002<\/p>\n<\/li>\n<\/ul>\n

    \u53ef\u7528\u547d\u4ee4 ttl key<\/code> \uff08\u4ee5\u79d2\u4e3a\u5355\u4f4d\uff09\u6216 pttl key<\/code> \uff08\u4ee5\u6beb\u79d2\u4e3a\u5355\u4f4d\uff09\u6765\u67e5\u770b key<\/code> \u8fd8\u6709\u591a\u4e45\u8fc7\u671f\u3002<\/p>\n

    Redis<\/code> \u53ef\u4ee5\u4f7f\u7528 time<\/code> \u547d\u4ee4\u67e5\u8be2\u5f53\u524d\u65f6\u95f4\u7684\u65f6\u95f4\u6233\uff08\u7cbe\u786e\u5230\u79d2\uff09\u3002<\/p>\n

    \u5b57\u7b26\u4e32\u4e2d\u51e0\u4e2a\u76f4\u63a5\u64cd\u4f5c\u8fc7\u671f\u65f6\u95f4\u7684\u65b9\u6cd5\uff0c\u5982\u4e0b\u5217\u8868\uff1a<\/p>\n

      \n
    • \n

      set key value ex seconds<\/code>\uff1a\u8bbe\u7f6e\u952e\u503c\u5bf9\u7684\u540c\u65f6\u6307\u5b9a\u8fc7\u671f\u65f6\u95f4\uff08\u7cbe\u786e\u5230\u79d2\uff09\u3002<\/p>\n<\/li>\n

    • \n

      set key value px milliseconds<\/code>\uff1a\u8bbe\u7f6e\u952e\u503c\u5bf9\u7684\u540c\u65f6\u6307\u5b9a\u8fc7\u671f\u65f6\u95f4\uff08\u7cbe\u786e\u5230\u6beb\u79d2\uff09\u3002<\/p>\n<\/li>\n

    • \n

      setex key seconds valule<\/code>\uff1a\u8bbe\u7f6e\u952e\u503c\u5bf9\u7684\u540c\u65f6\u6307\u5b9a\u8fc7\u671f\u65f6\u95f4\uff08\u7cbe\u786e\u5230\u79d2\uff09\u3002<\/p>\n<\/li>\n<\/ul>\n

      \u79fb\u9664\u8fc7\u671f\u65f6\u95f4<\/strong><\/p>\n

      \u4f7f\u7528\u547d\u4ee4\uff1a persist key<\/code> \u53ef\u4ee5\u79fb\u9664\u952e\u503c\u7684\u8fc7\u671f\u65f6\u95f4\u3002-1 \u8868\u793a\u6c38\u4e0d\u8fc7\u671f\u3002<\/p>\n

      Java \u5b9e\u73b0\u8fc7\u671f\u64cd\u4f5c<\/strong><\/p>\n

      \u4f7f\u7528 Jedis<\/code> \u6765\u5b9e\u73b0\u5bf9 Redis<\/code> \u7684\u64cd\u4f5c\uff0c\u4ee3\u7801\uff1a<\/p>\n

      public class TTLTest {\n    public static void main(String[] args) throws InterruptedException {\n        \/\/ \u521b\u5efa Redis \u8fde\u63a5\n        Jedis jedis = new Jedis(\"xxx.xxx.xxx.xxx\", 6379);\n        \/\/ \u8bbe\u7f6e Redis \u5bc6\u7801(\u5982\u679c\u6ca1\u6709\u5bc6\u7801\uff0c\u6b64\u884c\u53ef\u7701\u7565)\n        jedis.auth(\"xxx\");\n        \/\/ \u5b58\u50a8\u952e\u503c\u5bf9\uff08\u9ed8\u8ba4\u60c5\u51b5\u4e0b\u6c38\u4e0d\u8fc7\u671f\uff09\n        jedis.set(\"k\", \"v\");\n        \/\/ \u67e5\u8be2 TTL\uff08\u8fc7\u671f\u65f6\u95f4\uff09\n        Long ttl = jedis.ttl(\"k\");\n        \/\/ \u6253\u5370\u8fc7\u671f\u65e5\u5fd7\n        \/\/ \u8fc7\u671f\u65f6\u95f4\uff1a-1\n        System.out.println(\"\u8fc7\u671f\u65f6\u95f4\uff1a\" + ttl);\n        \/\/ \u8bbe\u7f6e 100s \u540e\u8fc7\u671f\n        jedis.expire(\"k\", 100);\n        \/\/ \u7b49\u5f85 1s \u540e\u6267\u884c\n        Thread.sleep(1000);\n        \/\/ \u6253\u5370\u8fc7\u671f\u65e5\u5fd7\n        \/\/ \u6267\u884c expire \u540e\u7684 TTL=99\n        System.out.println(\"\u6267\u884c expire \u540e\u7684 TTL=\" + jedis.ttl(\"k\"));\n    }\n}<\/pre>\n
      \u66f4\u591a\u8fc7\u671f\u64cd\u4f5c\u65b9\u6cd5<\/strong>\uff0c\u5982\u4e0b\u5217\u8868\uff1a<\/p>\n
        \n
      • \n
        pexpire(String key, long milliseconds)<\/code>\uff1a\u8bbe\u7f6e n \u6beb\u79d2\u540e\u8fc7\u671f\u3002<\/p>\n<\/li>\n
      • \n
        expireAt(String key, long unixTime)<\/code>\uff1a\u8bbe\u7f6e\u67d0\u4e2a\u65f6\u95f4\u6233\u540e\u8fc7\u671f\uff08\u7cbe\u786e\u5230\u79d2\uff09\u3002<\/p>\n<\/li>\n
      • \n
        pexpireAt(String key, long millisecondsTimestamp)<\/code>\uff1a\u8bbe\u7f6e\u67d0\u4e2a\u65f6\u95f4\u6233\u540e\u8fc7\u671f\uff08\u7cbe\u786e\u5230\u6beb\u79d2\uff09\u3002<\/p>\n<\/li>\n
      • \n
        persist(String key)<\/code>\uff1a\u79fb\u9664\u8fc7\u671f\u65f6\u95f4\u3002<\/p>\n<\/li>\n<\/ul>\n
        public class TTLTest {\n    public static void main(String[] args) throws InterruptedException {\n        \/\/ \u521b\u5efa Redis \u8fde\u63a5\n        Jedis jedis = new Jedis(\"xxx.xxx.xxx.xxx\", 6379);\n        \/\/ \u8bbe\u7f6e Redis \u5bc6\u7801(\u5982\u679c\u6ca1\u6709\u5bc6\u7801\uff0c\u6b64\u884c\u53ef\u7701\u7565)\n        jedis.auth(\"xxx\");\n        \/\/ \u5b58\u50a8\u952e\u503c\u5bf9\uff08\u9ed8\u8ba4\u60c5\u51b5\u4e0b\u6c38\u4e0d\u8fc7\u671f\uff09\n        jedis.set(\"k\", \"v\");\n        \/\/ \u67e5\u8be2 TTL\uff08\u8fc7\u671f\u65f6\u95f4\uff09\n        Long ttl = jedis.ttl(\"k\");\n        \/\/ \u6253\u5370\u8fc7\u671f\u65e5\u5fd7\n        System.out.println(\"\u8fc7\u671f\u65f6\u95f4\uff1a\" + ttl);\n        \/\/ \u8bbe\u7f6e 100s \u540e\u8fc7\u671f\n        jedis.expire(\"k\", 100);\n        \/\/ \u7b49\u5f85 1s \u540e\u6267\u884c\n        Thread.sleep(1000);\n        \/\/ \u6253\u5370\u8fc7\u671f\u65e5\u5fd7\n        System.out.println(\"\u6267\u884c expire \u540e\u7684 TTL=\" + jedis.ttl(\"k\"));\n        \/\/ \u8bbe\u7f6e n \u6beb\u79d2\u540e\u8fc7\u671f\n        jedis.pexpire(\"k\", 100000);\n        \/\/ \u8bbe\u7f6e\u67d0\u4e2a\u65f6\u95f4\u6233\u540e\u8fc7\u671f\uff08\u7cbe\u786e\u5230\u79d2\uff09\n        jedis.expireAt(\"k\", 1573468990);\n        \/\/ \u8bbe\u7f6e\u67d0\u4e2a\u65f6\u95f4\u6233\u540e\u8fc7\u671f\uff08\u7cbe\u786e\u5230\u6beb\u79d2\uff09\n        jedis.pexpireAt(\"k\", 1573468990000L);\n        \/\/ \u79fb\u9664\u8fc7\u671f\u65f6\u95f4\n        jedis.persist(\"k\");\n    }\n}<\/pre>\n
        \u6301\u4e45\u5316\u4e2d\u7684\u8fc7\u671f\u952e<\/strong><\/p>\n
        RDB \u4e2d\u7684\u8fc7\u671f\u952e<\/strong><\/h5>\n
        RDB<\/code> \u6587\u4ef6\u5206\u4e3a\u4e24\u4e2a\u9636\u6bb5\uff0cRDB<\/code> \u6587\u4ef6\u751f\u6210\u9636\u6bb5\u548c\u52a0\u8f7d\u9636\u6bb5\u3002<\/p>\n
        1. RDB \u6587\u4ef6\u751f\u6210<\/strong><\/p>\n
        RDB<\/code> \u52a0\u8f7d\u5206\u4e3a\u4ee5\u4e0b\u4e24\u79cd\u60c5\u51b5\uff1a<\/p>\n
          \n
        • \n
          \u5982\u679c Redis<\/code> \u662f\u4e3b<\/strong>\u670d\u52a1\u5668\u8fd0\u884c\u6a21\u5f0f\u7684\u8bdd\uff0c\u5728\u8f7d\u5165 RDB<\/code> \u6587\u4ef6\u65f6\uff0c\u7a0b\u5e8f\u4f1a\u5bf9\u6587\u4ef6\u4e2d\u4fdd\u5b58\u7684\u952e\u8fdb\u884c\u68c0\u67e5\uff0c\u8fc7\u671f\u952e\u4e0d\u4f1a\u88ab\u8f7d\u5165\u5230\u6570\u636e\u5e93\u4e2d\u3002\u6240\u4ee5\u8fc7\u671f\u952e\u4e0d\u4f1a\u5bf9\u8f7d\u5165 RDB<\/code> \u6587\u4ef6\u7684\u4e3b\u670d\u52a1\u5668\u9020\u6210\u5f71\u54cd\uff1b<\/p>\n<\/li>\n
        • \n
          \u5982\u679c Redis<\/code> \u662f\u4ece<\/strong>\u670d\u52a1\u5668\u8fd0\u884c\u6a21\u5f0f\u7684\u8bdd\uff0c\u5728\u8f7d\u5165 RDB<\/code> \u6587\u4ef6\u65f6\uff0c\u4e0d\u8bba\u952e\u662f\u5426\u8fc7\u671f\u90fd\u4f1a\u88ab\u8f7d\u5165\u5230\u6570\u636e\u5e93\u4e2d\u3002\u4f46\u7531\u4e8e\u4e3b\u4ece\u670d\u52a1\u5668\u5728\u8fdb\u884c\u6570\u636e\u540c\u6b65\u65f6\uff0c\u4ece\u670d\u52a1\u5668\u7684\u6570\u636e\u4f1a\u88ab\u6e05\u7a7a<\/strong>\u3002\u6240\u4ee5\u4e00\u822c\u6765\u8bf4\uff0c\u8fc7\u671f\u952e\u5bf9\u8f7d\u5165 RDB<\/code> \u6587\u4ef6\u7684\u4ece\u670d\u52a1\u5668\u4e5f\u4e0d\u4f1a\u9020\u6210\u5f71\u54cd\u3002<\/p>\n<\/li>\n<\/ul>\n
          RDB<\/code> \u6587\u4ef6\u52a0\u8f7d\u7684\u6e90\u7801\u53ef\u4ee5\u5728 rdb.c<\/code> \u6587\u4ef6\u7684 rdbLoad()<\/code> \u51fd\u6570\u4e2d\u627e\u5230\uff0c\u6e90\u7801\u6240\u793a\uff1a<\/p>\n
          \/* Check if the key already expired. This function is used when loading\n* an RDB file from disk, either at startup, or when an RDB was\n* received from the master. In the latter case, the master is\n* responsible for key expiry. If we would expire keys here, the\n* snapshot taken by the master may not be reflected on the slave. \n*\n* \u5982\u679c\u670d\u52a1\u5668\u4e3a\u4e3b\u8282\u70b9\u7684\u8bdd\uff0c\n* \u90a3\u4e48\u5728\u952e\u5df2\u7ecf\u8fc7\u671f\u7684\u65f6\u5019\uff0c\u4e0d\u518d\u5c06\u5b83\u4eec\u5173\u8054\u5230\u6570\u636e\u5e93\u4e2d\u53bb\n*\/\nif (server.masterhost == NULL && expiretime != -1 && expiretime < now) {\n    decrRefCount(key);\n    decrRefCount(val);\n    \/\/ \u8df3\u8fc7\n    continue;\n}<\/pre>\n
          AOF \u4e2d\u7684\u8fc7\u671f\u952e<\/strong><\/h5>\n
          1. AOF \u6587\u4ef6\u5199\u5165<\/strong><\/p>\n
          \u5f53 Redis<\/code> \u4ee5 AOF<\/code> \u6a21\u5f0f\u6301\u4e45\u5316\u65f6\uff0c\u5982\u679c\u6570\u636e\u5e93\u67d0\u4e2a\u8fc7\u671f\u952e\u8fd8\u6ca1\u88ab\u5220\u9664\uff0c\u90a3\u4e48 AOF<\/code> \u6587\u4ef6\u4f1a\u4fdd\u7559\u6b64\u8fc7\u671f\u952e\uff0c\u5f53\u6b64\u8fc7\u671f\u952e\u88ab\u5220\u9664\u540e\uff0cRedis<\/code> \u4f1a\u5411 AOF<\/code> \u6587\u4ef6\u8ffd\u52a0\u4e00\u6761 DEL<\/code> \u547d\u4ee4\u6765\u663e\u5f0f\u5730\u5220\u9664\u8be5\u952e\u503c\u3002<\/p>\n
          2. AOF \u91cd\u5199<\/strong><\/p>\n
          \u6267\u884c AOF<\/code> \u91cd\u5199\u65f6\uff0c\u4f1a\u5bf9 Redi<\/code>s \u4e2d\u7684\u952e\u503c\u5bf9\u8fdb\u884c\u68c0\u67e5\u5df2\u8fc7\u671f\u7684\u952e\u4e0d\u4f1a\u88ab\u4fdd\u5b58\u5230\u91cd\u5199\u540e\u7684 AOF<\/code> \u6587\u4ef6\u4e2d\uff0c\u56e0\u6b64\u4e0d\u4f1a\u5bf9 AOF<\/code> \u91cd\u5199\u9020\u6210\u4efb\u4f55\u5f71\u54cd\u3002<\/p>\n
          \u4e3b\u4ece\u5e93\u7684\u8fc7\u671f\u952e<\/strong><\/p>\n
          \u5f53 Redis<\/code> \u8fd0\u884c\u5728\u4e3b\u4ece\u6a21\u5f0f\u4e0b\u65f6\uff0c\u4ece\u5e93\u4e0d\u4f1a\u8fdb\u884c\u8fc7\u671f\u626b\u63cf\uff0c\u4ece\u5e93\u5bf9\u8fc7\u671f\u7684\u5904\u7406\u662f\u88ab\u52a8\u7684<\/strong>\u3002\u4e5f\u5c31\u662f\u5373\u4f7f\u4ece\u5e93\u4e2d\u7684 key<\/code> \u8fc7\u671f\u4e86\uff0c\u5982\u679c\u6709\u5ba2\u6237\u7aef\u8bbf\u95ee\u4ece\u5e93\u65f6\uff0c\u4f9d\u7136\u53ef\u4ee5\u5f97\u5230 key<\/code> \u5bf9\u5e94\u7684\u503c\uff0c\u50cf\u672a\u8fc7\u671f\u7684\u952e\u503c\u5bf9\u4e00\u6837\u8fd4\u56de\u3002<\/p>\n
          \u4ece\u5e93\u7684\u8fc7\u671f\u952e\u5904\u7406\u4f9d\u9760\u4e3b\u670d\u52a1\u5668\u63a7\u5236<\/strong>\uff0c\u4e3b\u5e93\u5728 key<\/code> \u5230\u671f\u65f6\uff0c\u4f1a\u5728 AOF<\/code> \u6587\u4ef6\u91cc\u589e\u52a0\u4e00\u6761 del<\/code> \u6307\u4ee4\uff0c\u540c\u6b65\u5230\u6240\u6709\u7684\u4ece\u5e93\uff0c\u4ece\u5e93\u901a\u8fc7\u6267\u884c\u8fd9\u6761 del<\/code> \u6307\u4ee4\u6765\u5220\u9664\u8fc7\u671f\u7684 key<\/code>\u3002<\/p>\n
          \u8fc7\u671f\u7b56\u7565<\/h3>\n
          \n
          \u5728 Redis<\/code> \u4e2d\u6211\u4eec\u53ef\u4ee5\u7ed9\u4e00\u4e9b\u5143\u7d20\u8bbe\u7f6e\u8fc7\u671f\u65f6\u95f4\uff0c\u90a3\u5f53\u5b83\u8fc7\u671f\u4e4b\u540e Redis<\/code> \u662f\u5982\u4f55\u5904\u7406\u8fd9\u4e9b\u8fc7\u671f\u952e\u5462\uff1f<\/p>\n<\/blockquote>\n
          \u8fc7\u671f\u952e\u6267\u884c\u6d41\u7a0b<\/strong><\/p>\n
          Redis<\/code> \u4e4b\u6240\u4ee5\u80fd\u77e5\u9053\u90a3\u4e9b\u952e\u503c\u8fc7\u671f\uff0c\u662f\u56e0\u4e3a\u5728 Redis<\/code> \u4e2d\u7ef4\u62a4\u4e86\u4e00\u4e2a\u5b57\u5178\uff0c\u5b58\u50a8\u4e86\u6240\u6709\u8bbe\u7f6e\u4e86\u8fc7\u671f\u65f6\u95f4\u7684\u952e\u503c\uff0c\u6211\u4eec\u79f0\u4e4b\u4e3a\u8fc7\u671f\u5b57\u5178<\/strong>\u3002<\/p>\n
          <\/p>\n
          \u8fc7\u671f\u952e\u6e90\u7801\u5206\u6790<\/strong><\/p>\n
          \u8fc7\u671f\u952e\u5b58\u50a8\u5728 redisDb<\/code> \u7ed3\u6784\u4e2d\uff0c\u6e90\u4ee3\u7801\u5728 src\/server.h<\/code> \u6587\u4ef6\u4e2d\uff08\u57fa\u4e8e Redis 5<\/code>\uff09\uff1a<\/p>\n
          \/* Redis database representation. There are multiple databases identified\n * by integers from 0 (the default database) up to the max configured\n * database. The database number is the 'id' field in the structure. *\/\ntypedef struct redisDb {\n    dict *dict;                 \/* \u6570\u636e\u5e93\u952e\u7a7a\u95f4\uff0c\u5b58\u653e\u7740\u6240\u6709\u7684\u952e\u503c\u5bf9 *\/\n    dict *expires;              \/* \u952e\u7684\u8fc7\u671f\u65f6\u95f4 *\/\n    dict *blocking_keys;        \/* Keys with clients waiting for data (BLPOP)*\/\n    dict *ready_keys;           \/* Blocked keys that received a PUSH *\/\n    dict *watched_keys;         \/* WATCHED keys for MULTI\/EXEC CAS *\/\n    int id;                     \/* Database ID *\/\n    long long avg_ttl;          \/* Average TTL, just for stats *\/\n    list *defrag_later;         \/* List of key names to attempt to defrag one by one, gradually. *\/\n} redisDb;<\/pre>\n
          \u8fc7\u671f\u952e\u6570\u636e\u7ed3\u6784\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n
          <\/p>\n
          \u8fc7\u671f\u7b56\u7565<\/strong><\/p>\n
          Redis<\/code> \u4f1a\u5220\u9664\u5df2\u8fc7\u671f\u7684\u952e\u503c\uff0c\u4ee5\u6b64\u6765\u51cf\u5c11 Redis<\/code> \u7684\u7a7a\u95f4\u5360\u7528\uff0c\u4f46\u56e0\u4e3a Redis<\/code> \u672c\u8eab\u662f\u5355\u7ebf\u7684\uff0c\u5982\u679c\u56e0\u4e3a\u5220\u9664\u64cd\u4f5c\u800c\u5f71\u54cd\u4e3b\u4e1a\u52a1\u7684\u6267\u884c\u5c31\u5f97\u4e0d\u507f\u5931\u4e86\uff0c\u4e3a\u6b64 Redis<\/code> \u9700\u8981\u5236\u5b9a\u591a\u4e2a\uff08\u8fc7\u671f\uff09\u5220\u9664\u7b56\u7565\u6765\u4fdd\u8bc1\u6b63\u5e38\u6267\u884c\u7684\u6027\u80fd\u3002<\/p>\n
          \u5b9a\u65f6\u5220\u9664<\/strong><\/h5>\n
          \u5728\u8bbe\u7f6e\u952e\u503c\u8fc7\u671f\u65f6\u95f4\u65f6\uff0c\u521b\u5efa\u4e00\u4e2a\u5b9a\u65f6\u4e8b\u4ef6\uff0c\u5f53\u8fc7\u671f\u65f6\u95f4\u5230\u8fbe\u65f6\uff0c\u7531\u4e8b\u4ef6\u5904\u7406\u5668\u81ea\u52a8\u6267\u884c\u952e\u7684\u5220\u9664\u64cd\u4f5c<\/strong>\u3002<\/p>\n
            \n
          • \n
            \u4f18\u70b9<\/strong>\uff1a\u4fdd\u8bc1\u5185\u5b58\u53ef\u4ee5\u88ab\u5c3d\u5feb\u5730\u91ca\u653e\u3002<\/p>\n<\/li>\n
          • \n
            \u7f3a\u70b9<\/strong>\uff1a\u5728 Redis<\/code> \u9ad8\u8d1f\u8f7d\u7684\u60c5\u51b5\u4e0b\u6216\u6709\u5927\u91cf\u8fc7\u671f\u952e\u9700\u8981\u540c\u65f6\u5904\u7406\u65f6\uff0c\u4f1a\u9020\u6210 Redis<\/code> \u670d\u52a1\u5668\u5361\u987f\uff0c\u5f71\u54cd\u4e3b\u4e1a\u52a1\u6267\u884c\u3002<\/p>\n<\/li>\n<\/ul>\n
            \u60f0\u6027\u5220\u9664<\/strong><\/h5>\n
            \u4e0d\u4e3b\u52a8\u5220\u9664\u8fc7\u671f\u952e\uff0c\u6bcf\u6b21\u4ece\u6570\u636e\u5e93\u83b7\u53d6\u952e\u503c\u65f6\u5224\u65ad\u662f\u5426\u8fc7\u671f\uff0c\u5982\u679c\u8fc7\u671f\u5219\u5220\u9664\u952e\u503c\uff0c\u5e76\u8fd4\u56de null<\/strong>\u3002<\/p>\n
              \n
            • \n
              \u4f18\u70b9<\/strong>\uff1a\u56e0\u4e3a\u6bcf\u6b21\u8bbf\u95ee\u65f6\uff0c\u624d\u4f1a\u5224\u65ad\u8fc7\u671f\u952e\uff0c\u6240\u4ee5\u6b64\u7b56\u7565\u53ea\u4f1a\u4f7f\u7528\u5f88\u5c11\u7684\u7cfb\u7edf\u8d44\u6e90\u3002<\/p>\n<\/li>\n
            • \n
              \u7f3a\u70b9<\/strong>\uff1a\u7cfb\u7edf\u5360\u7528\u7a7a\u95f4\u5220\u9664\u4e0d\u53ca\u65f6\uff0c\u5bfc\u81f4\u7a7a\u95f4\u5229\u7528\u7387\u964d\u4f4e\uff0c\u9020\u6210\u4e86\u4e00\u5b9a\u7684\u7a7a\u95f4\u6d6a\u8d39\u3002<\/p>\n<\/li>\n<\/ul>\n
              \u6e90\u7801\u89e3\u6790<\/p>\n
              \u60f0\u6027\u5220\u9664\u7684\u6e90\u7801\u4f4d\u4e8e src\/db.c<\/code> \u6587\u4ef6\u7684 expireIfNeeded<\/code> \u65b9\u6cd5\u4e2d\uff0c\u6e90\u7801\u5982\u4e0b\uff1a<\/p>\n
              int expireIfNeeded(redisDb *db, robj *key) {\n    \/\/ \u5224\u65ad\u952e\u662f\u5426\u8fc7\u671f\n    if (!keyIsExpired(db,key)) return 0;\n    if (server.masterhost != NULL) return 1;\n    \/* \u5220\u9664\u8fc7\u671f\u952e *\/\n    \/\/ \u589e\u52a0\u8fc7\u671f\u952e\u4e2a\u6570\n    server.stat_expiredkeys++;\n    \/\/ \u4f20\u64ad\u952e\u8fc7\u671f\u7684\u6d88\u606f\n    propagateExpire(db,key,server.lazyfree_lazy_expire);\n    notifyKeyspaceEvent(NOTIFY_EXPIRED,\n        \"expired\",key,db->id);\n    \/\/ server.lazyfree_lazy_expire \u4e3a 1 \u8868\u793a\u5f02\u6b65\u5220\u9664\uff08\u61d2\u7a7a\u95f4\u91ca\u653e\uff09\uff0c\u53cd\u4e4b\u540c\u6b65\u5220\u9664\n    return server.lazyfree_lazy_expire ? dbAsyncDelete(db,key) :\n                                         dbSyncDelete(db,key);\n}\n\/\/ \u5224\u65ad\u952e\u662f\u5426\u8fc7\u671f\nint keyIsExpired(redisDb *db, robj *key) {\n    mstime_t when = getExpire(db,key);\n    if (when < 0) return 0; \/* No expire for this key *\/\n    \/* Don't expire anything while loading. It will be done later. *\/\n    if (server.loading) return 0;\n    mstime_t now = server.lua_caller ? server.lua_time_start : mstime();\n    return now > when;\n}\n\/\/ \u83b7\u53d6\u952e\u7684\u8fc7\u671f\u65f6\u95f4\nlong long getExpire(redisDb *db, robj *key) {\n    dictEntry *de;\n    \/* No expire? return ASAP *\/\n    if (dictSize(db->expires) == 0 ||\n       (de = dictFind(db->expires,key->ptr)) == NULL) return -1;\n    \/* The entry was found in the expire dict, this means it should also\n     * be present in the main dict (safety check). *\/\n    serverAssertWithInfo(NULL,key,dictFind(db->dict,key->ptr) != NULL);\n    return dictGetSignedIntegerVal(de);\n}<\/pre>\n
              \u6240\u6709\u5bf9\u6570\u636e\u5e93\u7684\u8bfb\u5199\u547d\u4ee4\u5728\u6267\u884c\u4e4b\u524d\uff0c\u90fd\u4f1a\u8c03\u7528 expireIfNeeded<\/code> \u65b9\u6cd5\u5224\u65ad\u952e\u503c\u662f\u5426\u8fc7\u671f\uff0c\u8fc7\u671f\u5219\u4f1a\u4ece\u6570\u636e\u5e93\u4e2d\u5220\u9664\uff0c\u53cd\u4e4b\u5219\u4e0d\u505a\u4efb\u4f55\u5904\u7406\u3002<\/p>\n
              <\/p>\n
              \u5b9a\u671f\u5220\u9664<\/strong><\/h5>\n
              \u6bcf\u9694\u4e00\u6bb5\u65f6\u95f4\u68c0\u67e5\u4e00\u6b21\u6570\u636e\u5e93\uff0c\u968f\u673a\u5220\u9664\u4e00\u4e9b\u8fc7\u671f\u952e<\/strong>\u3002<\/p>\n
              Redis<\/code> \u9ed8\u8ba4\u6bcf\u79d2\u8fdb\u884c 10<\/code> \u6b21\u8fc7\u671f\u626b\u63cf\uff0c\u6b64\u914d\u7f6e\u53ef\u901a\u8fc7 Redis<\/code> \u7684\u914d\u7f6e\u6587\u4ef6 redis.conf \u8fdb\u884c\u914d\u7f6e\uff0c\u914d\u7f6e\u952e\u4e3a hz<\/code> \u5b83\u7684\u9ed8\u8ba4\u503c\u662f hz 10<\/code>\u3002<\/p>\n
              \u6ce8\u610f\uff1aRedis<\/code> \u6bcf\u6b21\u626b\u63cf\u5e76\u4e0d\u662f\u904d\u5386\u8fc7\u671f\u5b57\u5178\u4e2d\u7684\u6240\u6709\u952e\uff0c\u800c\u662f\u91c7\u7528\u968f\u673a\u62bd\u53d6\u5224\u65ad\u5e76\u5220\u9664\u8fc7\u671f\u952e\u7684\u5f62\u5f0f\u6267\u884c\u7684\u3002<\/p>\n
              \u5b9a\u671f\u5220\u9664\u6d41\u7a0b<\/strong><\/p>\n
                \n
              • \n
                \u4ece\u8fc7\u671f\u5b57\u5178\u4e2d\u968f\u673a\u53d6\u51fa 20 \u4e2a\u952e\u3002<\/p>\n<\/li>\n
              • \n
                \u5220\u9664\u8fd9 20 \u4e2a\u952e\u4e2d\u8fc7\u671f\u7684\u952e\u3002<\/p>\n<\/li>\n
              • \n
                \u5982\u679c\u8fc7\u671f key<\/code> \u7684\u6bd4\u4f8b\u8d85\u8fc7 25%\uff0c\u91cd\u590d\u6b65\u9aa4 1\u3002<\/p>\n<\/li>\n<\/ul>\n
                \u540c\u65f6\u4e3a\u4e86\u4fdd\u8bc1\u8fc7\u671f\u626b\u63cf\u4e0d\u4f1a\u51fa\u73b0\u5faa\u73af\u8fc7\u5ea6\uff0c\u5bfc\u81f4\u7ebf\u7a0b\u5361\u6b7b\u73b0\u8c61\uff0c\u7b97\u6cd5\u8fd8\u589e\u52a0\u4e86\u626b\u63cf\u65f6\u95f4\u7684\u4e0a\u9650\uff0c\u9ed8\u8ba4\u4e0d\u4f1a\u8d85\u8fc7 25ms\u3002<\/p>\n
                <\/p>\n
                  \n
                • \n
                  \u4f18\u70b9<\/strong>\uff1a\u901a\u8fc7\u9650\u5236\u5220\u9664\u64cd\u4f5c\u7684\u65f6\u957f\u548c\u9891\u7387\uff0c\u6765\u51cf\u5c11\u5220\u9664\u64cd\u4f5c\u5bf9 Redis<\/code> \u4e3b\u4e1a\u52a1\u7684\u5f71\u54cd\uff0c\u540c\u65f6\u4e5f\u80fd\u5220\u9664\u4e00\u90e8\u5206\u8fc7\u671f\u7684\u6570\u636e\u51cf\u5c11\u4e86\u8fc7\u671f\u952e\u5bf9\u7a7a\u95f4\u7684\u65e0\u6548\u5360\u7528\u3002<\/p>\n<\/li>\n
                • \n
                  \u7f3a\u70b9<\/strong>\uff1a\u5185\u5b58\u6e05\u7406\u65b9\u9762\u6ca1\u6709\u5b9a\u65f6\u5220\u9664\u6548\u679c\u597d\uff0c\u540c\u65f6\u6ca1\u6709\u60f0\u6027\u5220\u9664\u4f7f\u7528\u7684\u7cfb\u7edf\u8d44\u6e90\u5c11\u3002<\/p>\n<\/li>\n<\/ul>\n
                  \u6e90\u7801\u89e3\u6790<\/strong><\/p>\n
                  \u5b9a\u671f\u5220\u9664\u7684\u6838\u5fc3\u6e90\u7801\u5728 src\/expire.c<\/code> \u6587\u4ef6\u4e0b\u7684 activeExpireCycle<\/code> \u65b9\u6cd5\u4e2d\uff0c\u6e90\u7801\u5982\u4e0b\uff1a<\/p>\n
                  void activeExpireCycle(int type) {\n    static unsigned int current_db = 0; \/* \u4e0a\u6b21\u5b9a\u671f\u5220\u9664\u904d\u5386\u5230\u7684\u6570\u636e\u5e93ID *\/\n    static int timelimit_exit = 0;      \/* Time limit hit in previous call? *\/\n    static long long last_fast_cycle = 0; \/* \u4e0a\u4e00\u6b21\u6267\u884c\u5feb\u901f\u5b9a\u671f\u5220\u9664\u7684\u65f6\u95f4\u70b9 *\/\n    int j, iteration = 0;\n    int dbs_per_call = CRON_DBS_PER_CALL; \/\/ \u6bcf\u6b21\u5b9a\u671f\u5220\u9664\uff0c\u904d\u5386\u7684\u6570\u636e\u5e93\u7684\u6570\u91cf\n    long long start = ustime(), timelimit, elapsed;\n    if (clientsArePaused()) return;\n    if (type == ACTIVE_EXPIRE_CYCLE_FAST) {\n        if (!timelimit_exit) return;\n        \/\/ ACTIVE_EXPIRE_CYCLE_FAST_DURATION \u662f\u5feb\u901f\u5b9a\u671f\u5220\u9664\u7684\u6267\u884c\u65f6\u957f\n        if (start < last_fast_cycle + ACTIVE_EXPIRE_CYCLE_FAST_DURATION*2) return;\n        last_fast_cycle = start;\n    }\n    if (dbs_per_call > server.dbnum || timelimit_exit)\n        dbs_per_call = server.dbnum;\n    \/\/ \u6162\u901f\u5b9a\u671f\u5220\u9664\u7684\u6267\u884c\u65f6\u957f\n    timelimit = 1000000*ACTIVE_EXPIRE_CYCLE_SLOW_TIME_PERC\/server.hz\/100;\n    timelimit_exit = 0;\n    if (timelimit <= 0) timelimit = 1;\n    if (type == ACTIVE_EXPIRE_CYCLE_FAST)\n        timelimit = ACTIVE_EXPIRE_CYCLE_FAST_DURATION; \/* \u5220\u9664\u64cd\u4f5c\u7684\u6267\u884c\u65f6\u957f *\/\n    long total_sampled = 0;\n    long total_expired = 0;\n    for (j = 0; j < dbs_per_call && timelimit_exit == 0; j++) {\n        int expired;\n        redisDb *db = server.db+(current_db % server.dbnum);\n        current_db++;\n        do {\n            \/\/ .......\n            expired = 0;\n            ttl_sum = 0;\n            ttl_samples = 0;\n            \/\/ \u6bcf\u4e2a\u6570\u636e\u5e93\u4e2d\u68c0\u67e5\u7684\u952e\u7684\u6570\u91cf\n            if (num > ACTIVE_EXPIRE_CYCLE_LOOKUPS_PER_LOOP)\n                num = ACTIVE_EXPIRE_CYCLE_LOOKUPS_PER_LOOP;\n            \/\/ \u4ece\u6570\u636e\u5e93\u4e2d\u968f\u673a\u9009\u53d6 num \u4e2a\u952e\u8fdb\u884c\u68c0\u67e5\n            while (num--) {\n                dictEntry *de;\n                long long ttl;\n                if ((de = dictGetRandomKey(db->expires)) == NULL) break;\n                ttl = dictGetSignedInteger\n                \/\/ \u8fc7\u671f\u68c0\u67e5\uff0c\u5e76\u5bf9\u8fc7\u671f\u952e\u8fdb\u884c\u5220\u9664\n                if (activeExpireCycleTryExpire(db,de,now)) expired++;\n                if (ttl > 0) {\n                    \/* We want the average TTL of keys yet not expired. *\/\n                    ttl_sum += ttl;\n                    ttl_samples++;\n                }\n                total_sampled++;\n            }\n            total_expired += expired;\n            if (ttl_samples) {\n                long long avg_ttl = ttl_sum\/ttl_samples;\n                if (db->avg_ttl == 0) db->avg_ttl = avg_ttl;\n                db->avg_ttl = (db->avg_ttl\/50)*49 + (avg_ttl\/50);\n            }\n            if ((iteration & 0xf) == 0) { \/* check once every 16 iterations. *\/\n                elapsed = ustime()-start;\n                if (elapsed > timelimit) {\n                    timelimit_exit = 1;\n                    server.stat_expired_time_cap_reached_count++;\n                    break;\n                }\n            }\n            \/* \u6bcf\u6b21\u68c0\u67e5\u53ea\u5220\u9664 ACTIVE_EXPIRE_CYCLE_LOOKUPS_PER_LOOP\/4 \u4e2a\u8fc7\u671f\u952e *\/\n        } while (expired > ACTIVE_EXPIRE_CYCLE_LOOKUPS_PER_LOOP\/4);\n    }\n    \/\/ .......\n}<\/pre>\n
                  activeExpireCycle<\/code> \u65b9\u6cd5\u5728\u89c4\u5b9a\u7684\u65f6\u95f4\uff0c\u5206\u591a\u6b21\u904d\u5386\u5404\u4e2a\u6570\u636e\u5e93\uff0c\u4ece\u8fc7\u671f\u5b57\u5178\u4e2d\u968f\u673a\u68c0\u67e5\u4e00\u90e8\u5206\u8fc7\u671f\u952e\u7684\u8fc7\u671f\u65f6\u95f4\uff0c\u5220\u9664\u5176\u4e2d\u7684\u8fc7\u671f\u952e\u3002<\/p>\n
                  \u8fd9\u4e2a\u51fd\u6570\u6709\u4e24\u79cd\u6267\u884c\u6a21\u5f0f\uff0c\u4e00\u4e2a\u662f\u5feb\u901f\u6a21\u5f0f\u4e00\u4e2a\u662f\u6162\u901f\u6a21\u5f0f\uff0c\u4f53\u73b0\u662f\u4ee3\u7801\u4e2d\u7684 timelimit<\/code> \u53d8\u91cf\uff0c\u8fd9\u4e2a\u53d8\u91cf\u662f\u7528\u6765\u7ea6\u675f\u6b64\u51fd\u6570\u7684\u8fd0\u884c\u65f6\u95f4\u7684\u3002\u5feb\u901f\u6a21\u5f0f\u4e0b timelimit<\/code> \u7684\u503c\u662f\u56fa\u5b9a\u7684\uff0c\u7b49\u4e8e\u9884\u5b9a\u4e49\u5e38\u91cf ACTIVE_EXPIRE_CYCLE_FAST_DURATION<\/code>\uff0c\u6162\u901f\u6a21\u5f0f\u4e0b\uff0c\u8fd9\u4e2a\u53d8\u91cf\u7684\u503c\u662f\u901a\u8fc7 1000000 * ACTIVE_EXPIRE_CYCLE_SLOW_TIME_PERC\/server.hz\/100<\/code> \u8ba1\u7b97\u7684\u3002<\/p>\n
                  Redis \u4f7f\u7528\u7684\u8fc7\u671f\u7b56\u7565<\/strong><\/h5>\n
                  Redis<\/code> \u4f7f\u7528\u7684\u662f\u60f0\u6027\u5220\u9664\u52a0\u5b9a\u671f\u5220\u9664\u7684\u8fc7\u671f\u7b56\u7565<\/strong>\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
                  Redis\u4e2d\u8fc7\u671f\u64cd\u4f5c\u548c\u8fc7\u671f\u7b56\u7565\u7684...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-202176","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/202176","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"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=202176"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/202176\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=202176"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=202176"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=202176"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}