{"id":225004,"date":"2015-08-09T14:11:26","date_gmt":"2015-08-09T06:11:26","guid":{"rendered":"http:\/\/yangzhe1991.org\/blog\/?p=225004"},"modified":"2015-11-12T16:54:45","modified_gmt":"2015-11-12T08:54:45","slug":"ramp-transactions","status":"publish","type":"post","link":"https:\/\/yangzhe1991.org\/blog\/2015\/08\/ramp-transactions\/","title":{"rendered":"RAMP\u4e8b\u52a1"},"content":{"rendered":"<p>\u6700\u8fd1\u521a\u53d1\u73b0Cassandra\u8ba1\u5212\u5728\u672a\u6765\u652f\u6301\u201cRAMP\u4e8b\u52a1\u201d\u3002\u8fd9\u662fSIGMOD2014\u7684\u8bba\u6587\u300a<a href=\"http:\/\/www.bailis.org\/papers\/ramp-sigmod2014.pdf\">Scalable Atomic Visibility with RAMP Transactions<\/a>\u300b\u5f15\u5165\u7684\u6982\u5ff5\u3002\u672c\u6587\u7b97\u662f\u8bfb\u8bba\u6587\u7684\u7b14\u8bb0\u5427\u3002<\/p>\n<p>RAMP\u7684\u5168\u79f0\u662f\u201cRead Atomic MultiPartition\u201d\uff0c\u5c31\u662f\u5206\u5e03\u5f0f\u7684\u201c\u8bfb\u539f\u5b50\u6027\u201d\u3002\u6587\u7ae0\u5b9a\u4e49\u51fa\u4e00\u79cd\u65b0\u7684\u9694\u79bb\u6027\u2014\u2014Read Atomic Isolation\u3002\u7b80\u5355\u8bf4\u5c31\u662f\u5728\u5206\u5e03\u5f0f\u6570\u636e\u5e93\u4e2d\u4e00\u4e2a\u5bf9\u591a\u884c\u540c\u65f6\u5199\u5165\u7684\u4e8b\u52a1\uff0c\u9700\u8981\u4fdd\u8bc1\u5176\u4ed6\u5ba2\u6237\u7aef\u5728\u8bfb\u53d6\u4e8b\u52a1\u53d1\u751f\u65f6\u8981\u4e48\u53ef\u4ee5\u89c1\u5230\u5176\u4fee\u6539\u7684\u6240\u6709\u884c\uff0c\u8981\u4e48\u90fd\u89c1\u4e0d\u5230\u3002\u76f8\u5bf9\u6765\u8bf4\uff0cACID\u4e2d\u7684A\u662f\u63cf\u8ff0\u7684\u662f\u201c\u5199\u539f\u5b50\u6027\u201d\uff0c\u5199\u5165\u591a\u884c\u7684\u4e8b\u52a1\u8981\u4e48\u90fd\u6210\u529f\u8981\u4e48\u90fd\u4e0d\u6210\u529f\u3002\u800cCassandra\u5df2\u7ecf\u901a\u8fc7<a href=\"https:\/\/yangzhe1991.org\/blog\/2014\/12\/cassandra-code-reading-batch-implementation\/\">logged batch\u6765\u5b9e\u73b0\u4e86\u5199\u539f\u5b50\u6027<\/a>\u3002\u8bfb\u539f\u5b50\u6027\u53ea\u4fdd\u8bc1\u4e86\u5355\u4e2a\u5199\u5165\u4e8b\u52a1\u5728\u5176\u4ed6\u8bfb\u53d6\u4e8b\u52a1\u9762\u524d\u7684\u539f\u5b50\u6027\uff0c\u4f46\u662f\u591a\u4e2a\u4e8b\u52a1\u540c\u65f6\u5199\u7684\u8bdd\u4e0d\u4fdd\u8bc1\u9694\u79bb\u6027\u3002\u6240\u4ee5RA\u9694\u79bb\u6027\u7684\u4e8b\u52a1\u53ef\u4ee5\u6ee1\u8db3\u8bf8\u5982\u201c\u4e0d\u80fd\u5728\u67d0\u4e2a\u65f6\u523b\u540c\u65f6\u8bfb\u5230A\u7684\u597d\u53cb\u91cc\u6709B\uff0c\u800cB\u7684\u597d\u53cb\u91cc\u6ca1A\u7684\u72b6\u6001\u201d\u8fd9\u6837\u7684\u9700\u6c42\uff0c\u56e0\u4e3a\u8bbe\u7f6e\u597d\u53cb\u5173\u7cfb\u53ea\u9700\u8981\u4e24\u6761\u5199\u5165\u6307\u4ee4\u3002\u7ecf\u5178\u7684\u201c\u94f6\u884c\u8f6c\u8d26\u201d\u7c7b\u8de8\u884c\u4e8b\u52a1\u7684\u9700\u6c42\u56e0\u4e3a\u6d89\u53ca\u5230\u5e76\u53d1\u5199\u9700\u8981\u9694\u79bb\u51fa\u4e00\u4e2asnapshot\u6765\u5224\u65ad\u7528\u6237\u662f\u5426\u6709\u4f59\u989d\uff0c\u4e5f\u5c31\u662f\u5199\u4e4b\u524d\u8fd8\u5f97\u8bfb\u5e76\u4e14\u8981\u4fdd\u8bc1\u53e6\u4e00\u4e2a\u4e8b\u52a1\u8bfb\u7684\u65f6\u5019\u5fc5\u987b\u662f\u5f53\u524d\u4e8b\u52a1\u66f4\u65b0\u5b8c\u7ed3\u679c\u4e4b\u540e\u4e5f\u5c31\u662f\u8981\u5bf9\u8bfb\u52a0\u9501\uff0cRA\u9694\u79bb\u6027\u662f\u641e\u4e0d\u5b9a\u7684\u4e86\u3002\u7528\u9694\u79bb\u6027\u7684\u672f\u8bed\u6765\u8bf4\uff0cRAMP\u662f\u4fdd\u8bc1\u4e86Read Committed\u7ea7\u522b\uff0c\u4f46\u505a\u4e0d\u5230Repeatable reads\u3002\u8fd9\u5c31\u610f\u5473\u7740RAMP\u4e8b\u52a1\u53ea\u6ee1\u8db3\u4e86\u4e00\u90e8\u5206\u9700\u6c42\uff0c\u5f53\u7136\u6027\u80fd\u4e5f\u4f1a\u6bd4\u6ee1\u8db3\u5927\u90e8\u5206\u9700\u6c42\u7684\u8981\u597d\u3002<\/p>\n<p>\u5728\u4ecb\u7ecd\u7b97\u6cd5\u524d\uff0c\u8bba\u6587\u5bf9\u573a\u666f\u4e5f\u505a\u4e86\u4e00\u4e9b\u9650\u5236\uff0c\u5982\u4e0d\u540cclient\u7684\u4e8b\u52a1\u4e0d\u4f1a\u4e92\u76f8\u963b\u585e\u5bf9\u65b9\u3001\u6bcf\u4e2a\u8282\u70b9\u6302\u4e86\u90fd\u53ea\u5f71\u54cd\u5176\u4fdd\u5b58\u7684\u6570\u636e\u7684\u8bfb\u5199\u800c\u4e0d\u5e94\u8be5\u5f71\u54cd\u5176\u4ed6\u8282\u70b9\u4e0a\u6570\u636e\u7684\u8bfb\u5199\u3002\u6587\u7ae0\u79f0\u5176\u4e3a\u201cscalability criteria\u201d\uff0c\u540e\u9762\u63d0\u4f9b\u7684\u7b97\u6cd5\u5728\u4fdd\u8bc1scalability criteria\u7684\u60c5\u51b5\u4e0b\u4fdd\u8bc1\u4e86\u8bfb\u539f\u5b50\u6027\u3002<\/p>\n<p>\u6587\u7ae0\u63d0\u51fa\u4e86\u5b9e\u73b0RAMP\u7684\u7b97\u6cd5\u3002\u603b\u4f53\u6765\u8bf4\u601d\u8def\u662f\u8bfb\u4e8b\u52a1\u901a\u8fc7\u8bfb\u53d6\u5bf9\u5e94\u6570\u636e\u7684metadata\u6765\u5224\u65ad\u662f\u5426\u9047\u5230\u4e86\u8fdb\u884c\u4e00\u534a\u7684\u5199\u4e8b\u52a1\uff1b\u800c\u5199\u4e8b\u52a1\u4f7f\u7528\u4e8c\u9636\u6bb5\u63d0\u4ea4\u6765\u4fdd\u8bc1\u8bfb\u4e8b\u52a1\u8981\u4e48\u90fd\u8bfb\u8981\u4e48\u90fd\u4e0d\u8bfb\u3002\u6587\u7ae0\u63d0\u4f9b\u4e86\u4e09\u79cd\u5177\u4f53\u7684\u7b97\u6cd5\uff0c\u6765\u5728\u9700\u8981\u7684metadata\u7684\u6570\u91cf\u548c\u989d\u5916\u7684\u8bfb\u53d6\u6b21\u6570\u4e4b\u95f4\u505atradeoff\u3002\u5206\u522b\u53ebRAMP-Fast\u3001RAMP-Small\u3001RAMP-Hybrid\u3002<\/p>\n<h2>RAMP-Fast<\/h2>\n<p>\u7b97\u6cd5\u4e2d\u8bfb\u4e8b\u52a1\u9700\u89811-2\u8f6e\u901a\u4fe1\uff0c\u5199\u4e8b\u52a1\u9700\u89812\u8f6e\u901a\u4fe1\u3002<\/p>\n<p>\u670d\u52a1\u7aef\u9700\u8981\u5b58\u6bcf\u4e2akey\u7684\u6bcf\u4e2a\u7248\u672c\u7684value\u53ca\u5bf9\u5e94\u7684\u65f6\u95f4\u6233(ts)\u548cmetadata(md)\uff0c\u5e76\u4e14\u6bcf\u4e2akey\u5b58\u4e00\u4e2a\u6700\u8fd1\u4e00\u6b21commit\u7684\u65f6\u95f4\u6233\u3002\u670d\u52a1\u7aef\u5728\u5199\u5165\u7684\u65f6\u5019\u6709prepare\u548ccommit\u4e24\u4e2a\u64cd\u4f5c\uff0cprepare\u5c06key\u3001value\u3001ts\u3001md\u5b58\u5165\uff0c\u800ccommit\u65f6\u5c06\u5bf9\u5e94key\u7684latestCommit\u66f4\u65b0\u4e3amax(latestCommit, ts)\uff0cprepare\u548ccommit\u7684\u65f6\u95f4\u6233\u7531\u5ba2\u6237\u7aef\u63d0\u4f9b\u3002\u5ba2\u6237\u7aef\u5728\u5199\u5165\u7684\u65f6\u5019\u9996\u5148\u751f\u6210\u4e00\u4e2a\u65f6\u95f4\u6233\uff0c\u5e76\u9488\u5bf9\u6bcf\u4e2akey\u627e\u5230\u6240\u9700\u8981\u5b58\u50a8\u8be5key\u7684\u8282\u70b9\u53bb\u6267\u884cprepare\u64cd\u4f5c\uff0c\u5176\u4e2dmd\u4e3a\u9664\u4e86\u8fd9\u4e2akey\u4e4b\u5916\u8be5\u4e8b\u52a1\u6240\u8981\u5199\u7684\u5176\u4ed6\u6240\u6709key\u7684\u96c6\u5408\u3002\u6bcf\u4e2a\u8282\u70b9\u90fd\u6267\u884c\u5b8cprepare\u540e\u518d\u5728\u6bcf\u4e2a\u8282\u70b9\u6267\u884ccommit\u64cd\u4f5c\uff0c\u4e8c\u9636\u6bb5\u63d0\u4ea4\u5b8c\u6210\u3002<\/p>\n<p>\u670d\u52a1\u7aef\u5728\u8bfb\u7684\u65f6\u5019\u53ef\u4ee5\u6307\u5b9a\u4e00\u4e2a\u65f6\u95f4\u6233\u6765\u8bfb\uff0c\u4e5f\u53ef\u4ee5\u8bbe0\u8bfb\u53d6lastestCommit\u5bf9\u5e94\u7684\u65f6\u95f4\u6233\u7684\u503c\uff0c\u65f6\u95f4\u6233\u548cmetadata\u4e5f\u4e00\u5e76\u8fd4\u56de\u3002\u5ba2\u6237\u7aef\u5728\u8bfb\u7684\u65f6\u5019\u5199\u5728\u6bcf\u4e2akey\u5bf9\u5e94\u8282\u70b9\u4e0a\u4ee5ts=0\u6765\u8bfb\uff0c\u62ff\u5230\u7684\u4e00\u5768\u4e1c\u897f\u6328\u4e2a\u89e3\u6790\uff0c\u6bcf\u4e2akey\u4f1a\u8fd4\u56de\u8be5key\u5728\u8be5\u8282\u70b9\u6700\u8fd1\u4e00\u6b21\u4e8b\u52a1\u63d0\u4ea4\u7684\u65f6\u95f4\u6233\u548c\u5f53\u65f6\u63d0\u4ea4\u7684\u5176\u4f59n-1\u4e2akey\uff0c\u4e8c\u7ef4\u5faa\u73af\u6328\u4e2a\u6bd4\u5bf9\u6bcf\u4e2akey\u5728\u6240\u6709\u8bfb\u56de\u6765\u7684\u4e8b\u52a1\u91cc\u6700\u5927\u7684\u65f6\u95f4\u6233\uff0c\u5982\u679c\u53d1\u73b0\u67d0\u4e2akey\u8bfb\u56de\u6765\u7684value\u5bf9\u5e94\u7684\u65f6\u95f4\u6233\u4e0d\u5982\u5728\u5176\u4ed6key\u6240\u5e26\u56de\u7684md\u4e2d\u8be5key\u7684\u65f6\u95f4\u6233\u5927\uff0c\u5c31\u518d\u53bb\u5bf9\u5e94\u8282\u70b9\u8bfb\u6307\u5b9a\u65f6\u95f4\u6233\u7684value\u3002\u56e0\u4e3a\u522b\u7684\u8282\u70b9commit\u8fc7\u5fc5\u7136\u610f\u5473\u7740\u90a3\u6761\u4e8b\u52a1\u7684\u6240\u6709key\u5728\u6240\u6709\u8282\u70b9prepare\u8fc7\uff0c\u80af\u5b9a\u662f\u80fd\u8bfb\u5230\u5bf9\u5e94\u65f6\u95f4\u6233\u7684value\u7684\uff0c\u56e0\u6b64\u67d0\u6b21\u4e8b\u52a1\u4e00\u65e6\u6709\u4e00\u4e2a\u5ba2\u6237\u7aef\u8bfb\u5230\u4e86\u5176\u4e2d\u4e00\u4e2a\u88abcommit\u7684key\u5fc5\u7136\u53ef\u4ee5\u4fdd\u8bc1\u5176\u4ed6key\u4e5f\u53ef\u4ee5\u53bb\u5bf9\u5e94\u7684\u8282\u70b9\u8bfb\u5230\uff0c\u8fdb\u800c\u6574\u4e2a\u4e8b\u52a1\u7684\u6240\u6709\u884c\u90fd\u662f\u5b8c\u6574\u8bfb\u5230\u7684\uff0c\u4fdd\u8bc1\u4e86\u8bfb\u539f\u5b50\u6027\u3002<\/p>\n<p>\u7b80\u5355\u7c97\u66b4\u4f46\u662f\u9700\u8981md\u91cc\u5e26n-1\u4e2akey\uff0c\u5197\u4f59\u4fe1\u606f\u8f83\u591a\uff0c\u4f46\u6765\u56de\u901a\u4fe1\u7684\u8f6e\u6570\u8f83\u5c11\uff0c\u5199\u9700\u8981\u56fa\u5b9a\u4e24\u8f6e\uff0c\u8bfb\u6839\u636e\u60c5\u51b5\u9700\u89811\u8f6e\u6216\u4e24\u8f6e\u3002\u5f53\u4e14\u4ec5\u5f53\u67d0\u4e2a\u5199\u5165\u4e8b\u52a1\u6ca1\u6709\u5b8c\u5168commit\u5b8c\u5e76\u4e14\u8981\u8bfb\u53d6\u7684key\u4e2d\u6709\u4e24\u4e2akey\u6070\u597d\u5206\u522b\u5728\u8fd9\u6b21\u5199\u5165\u4e8b\u52a1\u4e2d\u88abcommit\u548c\u8fd8\u6ca1commit\u624d\u9700\u8981\u7b2c\u4e8c\u8f6e\u3002<\/p>\n<p>\u6b64\u5916\uff0c\u53ea\u8981\u4fdd\u8bc1\u4e0d\u540cclient\u7684\u65f6\u95f4\u6233\u6c38\u8fdc\u4e0d\u4e00\u6837\uff0c\u800c\u540cclient\u7684\u65f6\u95f4\u6233\u4e5f\u6c38\u8fdc\u4e0d\u4e00\u6837\uff08\u5f53\u7136\u8981\u4fdd\u8bc1\u5355\u8c03\u9012\u589e\u4f46\u8fd9\u4e2a\u5728\u5355\u673a\u5f88\u5bb9\u6613\uff09\uff0c\u5c31\u4e00\u5b9a\u53ef\u4ee5\u4fdd\u8bc1\u5bf9\u5e94\u4e8b\u52a1\u5168\u8bfb\u51fa\u6765\uff0c\u54ea\u6015\u4e0d\u540c\u8282\u70b9\u4e0a\u7684\u7cfb\u7edf\u65f6\u95f4\u6233\u6709\u8f83\u5927\u8bef\u5dee\u4e5f\u4e0d\u6015\uff08\u65e0\u975e\u662f\u5bfc\u81f4\u53ef\u80fd\u540e\u5199\u7684\u53cd\u800c\u88ab\u5148\u5199\u7684\u8986\u76d6\u56e0\u6b64\u8bfb\u4e0d\u5230\uff0c\u4f46\u81f3\u5c11\u662f\u90fd\u8bfb\u4e0d\u5230\uff09\u3002\u56e0\u6b64\u9700\u8981\u5728\u65f6\u95f4\u6233\u4e0a\u52a0\u5165client id\u6765\u786e\u4fdd\u4e0d\u540c\u8282\u7535\u65f6\u95f4\u6233\u6c38\u8fdc\u4e0d\u4f1a\u4e00\u6837\u3002<\/p>\n<p>&nbsp;<\/p>\n<h2>RAMP-Small<\/h2>\n<p>\u56e0\u4e3aRAMP-Fast\u9700\u8981\u7684\u989d\u5916\u7a7a\u95f4\u53d6\u51b3\u4e8e\u6bcf\u6b21\u4e8b\u52a1\u6240\u5199\u7684key\u6570\uff0c\u5982\u679c\u6bcf\u6b21\u90fd\u5199\u5f88\u591a\u4e2akey\u4f1a\u5f88\u8017\u8d39\u7a7a\u95f4\u3002\u56e0\u6b64\u53c8\u6709\u4e2a\u4e0d\u9700\u8981metadata\u7684\u7b97\u6cd5\uff0c\u4f46\u6bcf\u6b21\u8bfb\u53d6\u90fd\u9700\u8981\u4e24\u8f6e\u901a\u4fe1\u3002<\/p>\n<p>\u670d\u52a1\u7aef\u7684prepare\u548ccommit\u548cRAMP-Fast\u6ca1\u533a\u522b\uff0c\u4f46\u662f\u8bfb\u53d6\u64cd\u4f5c\u8981\u4f20\u7684\u5e76\u975e\u662f\u4e00\u4e2a\u7279\u5b9a\u7684\u65f6\u95f4\u6233\u800c\u662f\u4e00\u4e2a\u65f6\u95f4\u6233\u7684\u96c6\u5408\u3002\u5982\u679c\u96c6\u5408\u4e3a\u7a7a\u8fd4\u56delastedCommit\u5bf9\u5e94\u7684\u7248\u672c\u7684ts\uff08\u4e0d\u9700\u8981value\uff09\uff0c\u800c\u5982\u679c\u662f\u67e5\u8be2\u4e00\u4e2a\u65f6\u95f4\u6233\u96c6\u5408\uff0c\u628a\u96c6\u5408\u4e2d\u7684\u65f6\u95f4\u6233\u4ece\u5927\u5230\u5c0f\u5206\u522b\u67e5\u8be2\uff0c\u4e00\u65e6\u67e5\u5230\u8be5key\u6709\u67d0\u4e2a\u7248\u672c\u7684\u65f6\u95f4\u6233\u4e0e\u4e4b\u76f8\u7b49\u5c31\u8fd4\u56de\u8fd9\u4e2a\u7248\u672c\u7684value\u548cts\u3002<\/p>\n<p>\u5ba2\u6237\u7aef\u7684\u5199\u5165\u4e5f\u548cRAMP-Fast\u6ca1\u533a\u522b\u53ea\u662f\u4e0d\u9700\u8981metadata\u4e86\u3002\u7b2c\u4e00\u8f6e\u8bfb\u53d6\u8bbe\u65f6\u95f4\u6233\u96c6\u5408\u4e3a\u7a7a\uff0c\u628a\u6bcf\u4e2akey\u7684commit ts\u90fd\u8bfb\u56de\u6765\uff0c\u6bcf\u4e2akey\u6240\u8fd4\u56de\u7684\u65f6\u95f4\u6233\u4f5c\u4e3a\u7b2c\u4e8c\u8f6e\u67e5\u8be2\u7684\u65f6\u95f4\u6233\u96c6\u5408\u3002\u56e0\u4e3a\u7b2c\u4e00\u8f6e\u62ff\u5230\u7684\u6240\u6709commit ts\u5728\u7b2c\u4e8c\u8f6e\u90fd\u4f20\u5165\u6bcf\u4e2a\u8282\u70b9\u67e5\u8be2\uff0c\u4f1a\u4fdd\u8bc1\u6bcf\u4e2akey\u90fd\u5c3d\u91cf\u8fd4\u56de\u8fd9\u4e2ats\u96c6\u5408\u4e2d\u6240\u5305\u542b\u7684\u6700\u5927\u65f6\u95f4\u6233\u5bf9\u5e94\u7684\u7248\u672c\u7684value\u3002\u6240\u4ee5\u4e5f\u4e0d\u4f1a\u51fa\u73b0\u67d0\u6b21\u4e8b\u52a1\u6709\u4e9bkey\u80fd\u8bfb\u6709\u4e9bkey\u8bfb\u4e0d\u5230\u7684\u60c5\u51b5\u3002<\/p>\n<p>\u8bfb\u53d6\u7684\u8f6e\u6570\u591a\u4e86\uff0c\u4f46\u9700\u8981\u7684\u7a7a\u95f4\u548c\u4f20\u8f93\u6570\u636e\u7684\u91cf\u90fd\u5c0f\u4e86\u3002<\/p>\n<h2>RAMP-Hybrid<\/h2>\n<p>\u524d\u4e24\u7ec4\u57fa\u672c\u7b97\u6cd5\u7684\u6838\u5fc3\u601d\u60f3\u6781\u5176\u6b63\u786e\u6027\u7684\u8bc1\u660e\u90fd\u5f88\u5bb9\u6613\u7406\u89e3\u2014\u2014\u5199\u5165\u65f6\u6bcf\u884c\u90fd\u6210\u529fprepare\u624d\u53ef\u80fdcommit\uff0c\u4e00\u65e6\u67d0\u884c\u88abcommit\u5fc5\u7136\u53ef\u4ee5\u628a\u8fd9\u6b21\u4e8b\u52a1\u7684\u5168\u90e8\u5176\u4ed6\u884c\u90fd\u6309\u65f6\u95f4\u6233\u627e\u51fa\u6765\u3002\u533a\u522b\u53ea\u662f\u662f\u5426\u6709metadata\u56e0\u800c\u662f\u5426\u9700\u8981\u7b2c\u4e8c\u6b21\u8bfb\u53d6\u3002<\/p>\n<p>\u800c\u7b2c\u4e09\u79cdRAMP-Hybrid\u7b97\u6cd5\uff0c\u5199\u5165\u65f6\u662f\u5728metadata\u4e2d\u8bb0\u5f55\u8be5\u6b21\u4e8b\u52a1\u5176\u4ed6key\u96c6\u5408\u5bf9\u5e94\u7684bloom filter\u800c\u975eFast\u4e2d\u5b8c\u6574\u7684key\u96c6\u5408\u3002\u4e8e\u662f\u5f88\u5bb9\u6613\u60f3\u660e\u767d\uff0c\u7b2c\u4e00\u8f6e\u8bfb\u53d6\u65f6\u628alastedCommit\u7684ts\u548cvalue\u548cmd\u90fd\u8fd4\u56de\uff0c\u7136\u540e\u628a\u8fd9\u6b21\u8bfb\u53d6\u4e8b\u52a1\u9700\u8981\u7684\u5176\u4ed6key\u5728\u8fd9\u4e2abloom filter\u8fc7\u4e00\u904d\u3002\u56e0\u4e3abloom filter\u80fd\u5224\u65ad\u4e00\u4e2a\u5143\u7d20\u662f\u4e00\u5b9a\u4e0d\u5728\u8fd9\u4e2a\u96c6\u5408\u8fd8\u662f\u5927\u6982\u7387\u5728\u8fd9\u4e2a\u96c6\u5408\uff0c\u6240\u4ee5\u5982\u679c\u8fd4\u56de\u7684commit ts\u6bd4\u5176\u4ed6\u67d0\u4e2akey\u62ff\u56de\u6765\u7684commit ts\u5c0f\u5c31\u4e0d\u7ba1\u4e86\uff0c\u5982\u679c\u5927\u5c31\u8fc7\u4e00\u904dbloom filter\uff0c\u4e00\u65e6\u8fd4\u56defalse\u5c31\u7701\u53bb\u7b2c\u4e8c\u6b21\uff0c\u800c\u8fd4\u56detrue\u5c31\u53bb\u7b2c\u4e8c\u8f6e\u62ff\u5bf9\u5e94ts\u7684value\uff0c\u5f53\u7136\u53ef\u80fd\u662f\u6ca1\u6709\u7684\u56e0\u4e3abloom filter\u6709false positive\u7684\u53ef\u80fd\u3002<\/p>\n<p>\u56e0\u800cHybrid\u7b97\u6cd5\u9700\u8981\u7684\u989d\u5916\u7a7a\u95f4\u662f\u4e00\u4e2abloom filter\uff0c\u51e0\u4e4e\u662f\u4e2a\u6bd4\u8f83\u5c0f\u7684\u5e38\u91cf\u7ea7\u7684\u7a7a\u95f4\uff08\u800c\u975e\u6b63\u6bd4\u4e8e\u6bcf\u6b21\u5199\u5165\u4e8b\u52a1\u4e2dkey\u7684\u6570\u91cf\uff09\u5e76\u4e14\u53ef\u4ee5\u6839\u636e\u96c6\u5408\u6570\u91cf\u548c\u5141\u8bb8\u7684\u8bef\u5dee\u5ea6\u8c03\u6574\u3002\u5e76\u4e14\u548cFast\u7b97\u6cd5\u4e2d\u7684\u9700\u8981\u7b2c\u4e8c\u8f6e\u8bfb\u53d6\u7684\u6982\u7387\u6bd4\u53ea\u662f\u5927\u4e86bloom filter\u53d1\u751ffalse positive\u65f6\u7684\u6982\u7387\u3002\u5982\u679cfalse positive\u7387\u4e3a0\uff0cHybrid\u76f8\u5f53\u4e8e\u662fFast\uff1b\u5982\u679c\u4e3a1\uff0c\u4f1a\u7ea6\u7b49\u4e8e\u9000\u5316\u6210Small\u3002\u800cfalse positive\u7684\u6982\u7387\u5f88\u5c0f\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>\u7b97\u6cd5\u7684\u6838\u5fc3\u8bf4\u5230\u8fd9\u5df2\u7ecf\u7ed3\u675f\uff0c\u5f88\u591a\u4eba\u53ef\u80fd\u89c9\u5f97\u81ea\u5df1\u5199\u4e00\u4e2a\u51fa\u6765\u90fd\u4e0d\u96be\u3002<\/p>\n<p>\u63a5\u4e0b\u6765\u9996\u5148\u8bb2\u4e86\u4e00\u4e9b\u5b9e\u73b0\u95ee\u9898\uff0c\u6700\u91cd\u8981\u7684\u662f\u5783\u573e\u56de\u6536\uff0c\u54ea\u4e9b\u6570\u636e\u53ef\u4ee5\u56de\u6536\u662f\u663e\u800c\u6613\u89c1\u7684\u2014\u2014\u6bd4lastedCommit\u5c0f\u7684\u7248\u672c\u7684\u6570\u636e\u5168\u53ef\u4ee5\u4e0d\u8981\u4e86\u3002\u4f46\u662f\u5b58\u5728\u4e00\u4e9b\u65e7\u7248\u672c\u7684\u8bfb\u53ef\u80fd\u8fd8\u9700\u8981\u8bfb\u5c0f\u4e00\u4e9b\u7684\u6570\u636e\u56e0\u4e3a\u4ed6\u53ef\u80fd\u5728\u8bfb\u7b2c\u4e00\u8f6e\u7684\u65f6\u5019\u4e0d\u77e5\u9053\u65b0\u7684commit\uff0c\u8fd9\u65f6\u5019\u5f3a\u5236reader\u91cd\u65b0\u8bfb\u4e5f\u53ef\u4ee5\uff0c\u66f4\u597d\u7684\u65b9\u5f0f\u662f\u65e7\u6570\u636e\u7559\u4e00\u6bb5\u65f6\u95f4\u518d\u5220\u3002\u7136\u540e\u4ed6\u4e5f\u8bf4\u8fd9\u4e2a\u7b97\u6cd5\u4e2d\u5199\u64cd\u4f5c\u88ab\u7b80\u5316\u6210\u4e86\u7c7b\u4f3cCassandra\u7684\u201chighest-timestamp-wins 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 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[26],"_links":{"self":[{"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/posts\/225004"}],"collection":[{"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/comments?post=225004"}],"version-history":[{"count":6,"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/posts\/225004\/revisions"}],"predecessor-version":[{"id":225068,"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/posts\/225004\/revisions\/225068"}],"wp:attachment":[{"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/media?parent=225004"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/categories?post=225004"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/tags?post=225004"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}