{"id":201409,"date":"2025-05-10T08:38:37","date_gmt":"2025-05-10T00:38:37","guid":{"rendered":"https:\/\/server.hk\/cnblog\/201409\/"},"modified":"2025-05-10T08:38:37","modified_gmt":"2025-05-10T00:38:37","slug":"redis%e8%a2%abbgsave%e5%92%8cbgrewriteaof%e9%98%bb%e5%a1%9e%e7%9a%84%e8%a7%a3%e5%86%b3%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/201409\/","title":{"rendered":"Redis\u88abbgsave\u548cbgrewriteaof\u963b\u585e\u7684\u89e3\u51b3\u65b9\u6cd5"},"content":{"rendered":"

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

Redis\u88abbgsave\u548cbgrewriteaof\u963b\u585e\u7684\u89e3\u51b3\u65b9\u6cd5<\/h1>\n

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

\u4eb2\u7231\u7684\u7f16\u7a0b\u5b66\u4e60\u7231\u597d\u8005\uff0c\u5982\u679c\u4f60\u70b9\u5f00\u4e86\u8fd9\u7bc7\u6587\u7ae0\uff0c\u8bf4\u660e\u4f60\u5bf9\u300aRedis\u88abbgsave\u548cbgrewriteaof\u963b\u585e\u7684\u89e3\u51b3\u65b9\u6cd5\u300b\u5f88\u611f\u5174\u8da3\u3002\u672c\u7bc7\u6587\u7ae0\u5c31\u6765\u7ed9\u5927\u5bb6\u8be6\u7ec6\u89e3\u6790\u4e00\u4e0b\uff0c\u4e3b\u8981\u4ecb\u7ecd\u4e00\u4e0bRedis\u3001bgsave\u3001bgrewriteaof\uff0c\u5e0c\u671b\u6240\u6709\u8ba4\u771f\u8bfb\u5b8c\u7684\u7ae5\u978b\u4eec\uff0c\u90fd\u6709\u5b9e\u8d28\u6027\u7684\u63d0\u9ad8\u3002<\/p>\n

Redis \u662f\u4e00\u4e2a\u6027\u80fd\u975e\u5e38\u9ad8\u6548\u7684\u5185\u5b58 Key-Value \u5b58\u50a8\u670d\u52a1, \u540c\u65f6\u5b83\u8fd8\u5177\u6709\u4e24\u4e2a\u975e\u5e38\u91cd\u8981\u7684\u7279\u6027: 1. \u6301\u4e45\u5316; 2. Value \u6570\u636e\u7ed3\u6784. \u8fd9\u4e24\u4e2a\u7279\u6027\u8ba9\u5b83\u5728\u4e0d\u5c11\u573a\u666f\u8f7b\u677e\u51fb\u8d25\u4e86 Memcached \u548c Casandra \u7b49.<\/p>\n

    Redis \u7684\u6301\u4e45\u5316\u5728\u4e24\u79cd\u65b9\u5f0f: Snapshotting(\u5feb\u7167) \u548c Append-only file(aof). \u5728\u4e00\u4e2a\u91c7\u7528\u4e86 aof \u6a21\u5f0f\u7684 Redis \u670d\u52a1\u5668\u4e0a, \u5f53\u6267\u884c bgrewriteaof \u5bf9 aof \u8fdb\u884c\u5f52\u5e76\u4f18\u5316\u65f6, \u51fa\u73b0\u4e86 Redis \u88ab\u963b\u585e\u7684\u95ee\u9898, \u6b64\u65f6, Redis \u65e0\u6cd5\u63d0\u4f9b\u4efb\u4f55\u8bfb\u53d6\u548c\u5199\u5165\u64cd\u4f5c.<\/p>\n

    \u6309\u5b57\u9762\u7406\u89e3, bgrewriteaof \u662f\u5728\u540e\u53f0\u8fdb\u884c\u64cd\u4f5c, \u4e0d\u5e94\u8be5\u5f71\u54cd Redis \u7684\u6b63\u5e38\u670d\u52a1. \u539f\u7406\u4e5f\u786e\u5b9e\u662f\u8fd9\u6837\u7684, Redis \u9996\u5148 fork \u4e00\u4e2a\u5b50\u8fdb\u7a0b, \u5e76\u5728\u8be5\u5b50\u8fdb\u7a0b\u91cc\u8fdb\u884c\u5f52\u5e76\u548c\u5199\u6301\u4e45\u5316\u5b58\u50a8\u8bbe\u5907(\u5982\u786c\u76d8)\u7684. \u6309\u7167\u6b63\u5e38\u903b\u8f91, \u5728\u4e00\u53f0\u591a\u6838\u7684\u673a\u5668\u4e0a, \u5373\u4f7f\u5b50\u8fdb\u7a0b\u5360\u6ee1 CPU \u548c\u786c\u76d8, \u4e5f\u4e0d\u5e94\u8be5\u5bfc\u81f4 Redis \u670d\u52a1\u963b\u585e\u554a!<\/p>\n

    \u5176\u5b9e, \u95ee\u9898\u5c31\u51fa\u5728\u786c\u76d8\u4e0a.<\/p>\n

    Redis \u670d\u52a1\u8bbe\u7f6e\u4e86 appendfsync everysec, \u4e3b\u8fdb\u7a0b\u6bcf\u79d2\u949f\u4fbf\u4f1a\u8c03\u7528 fsync(), \u8981\u6c42\u5185\u6838\u5c06\u6570\u636e\u201d\u786e\u5b9e\u201d\u5199\u5230\u5b58\u50a8\u786c\u4ef6\u91cc. \u4f46\u7531\u4e8e\u5b50\u8fdb\u7a0b\u540c\u65f6\u4e5f\u5728\u5199\u786c\u76d8, \u4ece\u800c\u5bfc\u81f4\u4e3b\u8fdb\u7a0b fsync()\/write() \u64cd\u4f5c\u88ab\u963b\u585e, \u6700\u7ec8\u5bfc\u81f4 Redis \u4e3b\u8fdb\u7a0b\u963b\u585e\u4e86.<\/p>\n

    \u89e3\u51b3\u65b9\u6cd5\u4fbf\u662f\u8bbe\u7f6e no-appendfsync-on-rewrite yes, \u5728\u5b50\u8fdb\u7a0b\u5904\u7406\u548c\u5199\u786c\u76d8\u65f6, \u4e3b\u8fdb\u7a0b\u4e0d\u8c03\u7528 fsync() \u64cd\u4f5c. \u6ce8\u610f, \u5373\u4f7f\u8fdb\u7a0b\u4e0d\u8c03\u7528 fsync(), \u7cfb\u7edf\u5185\u6838\u4e5f\u4f1a\u6839\u636e\u81ea\u5df1\u7684\u7b97\u6cd5\u5728\u9002\u5f53\u7684\u65f6\u673a\u5c06\u6570\u636e\u5199\u5230\u786c\u76d8(Linux \u9ed8\u8ba4\u6700\u957f\u4e0d\u8d85\u8fc7 30 \u79d2).<\/p>\n","protected":false},"excerpt":{"rendered":"

Redis\u88abbgsave\u548cbgr...<\/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-201409","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/201409","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=201409"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/201409\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=201409"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=201409"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=201409"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}