{"id":151,"date":"2016-05-03T00:45:06","date_gmt":"2016-05-02T16:45:06","guid":{"rendered":"https:\/\/wangqf.com\/?p=151"},"modified":"2016-05-03T00:45:06","modified_gmt":"2016-05-02T16:45:06","slug":"%e4%b8%80%e8%87%b4%e6%80%a7%e5%93%88%e5%b8%8c%e7%ae%97%e6%b3%95","status":"publish","type":"post","link":"https:\/\/wangqf.com\/?p=151","title":{"rendered":"\u4e00\u81f4\u6027\u54c8\u5e0c\u7b97\u6cd5"},"content":{"rendered":"<p>\u5728\u5206\u5e03\u5f0f\u7f13\u5b58\u548c\u5206\u5e03\u5f0f\u5b58\u50a8\u7cfb\u7edf\u4e0a\u7ecf\u5e38\u7528\u5230\u4e00\u81f4\u6027\u54c8\u5e0c\u7b97\u6cd5\uff0c\u4eca\u5929\u7279\u5730\u6765\u5b66\u4e60\u4e00\u4e0b\u3002<\/p>\n<p><b>\u4e00\u81f4\u54c8\u5e0c<\/b> \u662f\u4e00\u79cd\u7279\u6b8a\u7684\u54c8\u5e0c\u7b97\u6cd5\u3002\u5728\u4f7f\u7528\u4e00\u81f4\u54c8\u5e0c\u7b97\u6cd5\u540e\uff0c\u54c8\u5e0c\u8868\u69fd\u4f4d\u6570\uff08\u5927\u5c0f\uff09\u7684\u6539\u53d8\u5e73\u5747\u53ea\u9700\u8981\u5bf9<img decoding=\"async\" class=\"mwe-math-fallback-image-inline tex\" src=\"https:\/\/upload.wikimedia.org\/math\/8\/6\/e\/86e8b371e8e97721503be8c7eba99530.png\" alt=\"K\/n\" \/> \u4e2a\u5173\u952e\u5b57\u91cd\u65b0\u6620\u5c04\uff0c\u5176\u4e2d <img decoding=\"async\" class=\"mwe-math-fallback-image-inline tex\" src=\"https:\/\/upload.wikimedia.org\/math\/a\/5\/f\/a5f3c6a11b03839d46af9fb43c97c188.png\" alt=\"K\" \/>\u662f\u5173\u952e\u5b57\u7684\u6570\u91cf\uff0c<img decoding=\"async\" class=\"mwe-math-fallback-image-inline tex\" src=\"https:\/\/upload.wikimedia.org\/math\/7\/b\/8\/7b8b965ad4bca0e41ab51de7b31363a1.png\" alt=\"n\" \/>\u662f\u69fd\u4f4d\u6570\u91cf\u3002\u7136\u800c\u5728\u4f20\u7edf\u7684\u54c8\u5e0c\u8868\u4e2d\uff0c\u6dfb\u52a0\u6216\u5220\u9664\u4e00\u4e2a\u69fd\u4f4d\u7684\u51e0\u4e4e\u9700\u8981\u5bf9\u6240\u6709\u5173\u952e\u5b57\u8fdb\u884c\u91cd\u65b0\u6620\u5c04\u3002<\/p>\n<h2><span id=\".E5.8E.86.E5.8F.B2\" class=\"mw-headline\">\u5386\u53f2<\/span><\/h2>\n<p>\u4e00\u81f4\u54c8\u5e0c\u7531MIT\u7684Karger\u53ca\u5176\u5408\u4f5c\u8005\u63d0\u51fa\uff0c\u73b0\u5728\u8fd9\u4e00\u601d\u60f3\u5df2\u7ecf\u6269\u5c55\u5230\u5176\u5b83\u9886\u57df\u3002\u5728\u8fd9\u7bc71997\u5e74\u53d1\u8868\u7684\u5b66\u672f\u8bba\u6587\u4e2d\u4ecb\u7ecd\u4e86\u201c\u4e00\u81f4\u54c8\u5e0c\u201d\u5982\u4f55\u5e94\u7528\u4e8e\u7528\u6237\u6613\u53d8\u7684\u5206\u5e03\u5f0fWeb\u670d\u52a1\u4e2d<a href=\"http:\/\/dl.acm.org\/citation.cfm?id=258660\" target=\"_blank\" rel=\"noopener\">[1]<\/a>\u3002\u54c8\u5e0c\u8868\u4e2d\u7684\u6bcf\u4e00\u4e2a\u4ee3\u8868\u5206\u5e03\u5f0f\u7cfb\u7edf\u4e2d\u4e00\u4e2a\u8282\u70b9\uff0c\u5728\u7cfb\u7edf\u6dfb\u52a0\u6216\u5220\u9664\u8282\u70b9\u53ea\u9700\u8981\u79fb\u52a8<img decoding=\"async\" class=\"mwe-math-fallback-image-inline tex\" src=\"https:\/\/upload.wikimedia.org\/math\/8\/6\/e\/86e8b371e8e97721503be8c7eba99530.png\" alt=\"K\/n\" \/>\u9879\u3002<\/p>\n<p>\u4e00\u81f4\u54c8\u5e0c\u4e5f\u53ef\u7528\u4e8e\u5b9e\u73b0\u5065\u58ee\u7f13\u5b58\u6765\u51cf\u5c11\u5927\u578bWeb\u5e94\u7528\u4e2d\u7cfb\u7edf\u90e8\u5206\u5931\u6548\u5e26\u6765\u7684\u8d1f\u9762\u5f71\u54cd\u3002<\/p>\n<p>\u4e00\u81f4\u54c8\u5e0c\u7684\u6982\u5ff5\u8fd8\u88ab\u5e94\u7528\u4e8e\u5206\u5e03\u5f0f\u6563\u5217\u8868\uff08DHT\uff09\u7684\u8bbe\u8ba1\u3002DHT\u4f7f\u7528\u4e00\u81f4\u54c8\u5e0c\u6765\u5212\u5206\u5206\u5e03\u5f0f\u7cfb\u7edf\u7684\u8282\u70b9\u3002\u6240\u6709\u5173\u952e\u5b57\u90fd\u53ef\u4ee5\u901a\u8fc7\u4e00\u4e2a\u8fde\u63a5\u6240\u6709\u8282\u70b9\u7684\u8986\u76d6\u7f51\u7edc\u9ad8\u6548\u5730\u5b9a\u4f4d\u5230\u67d0\u4e2a\u8282\u70b9\u3002<\/p>\n<h2><span id=\".E9.9C.80.E6.B1.82\" class=\"mw-headline\">\u9700\u6c42<\/span><\/h2>\n<p>\u5728\u4f7f\u7528n\u53f0\u7f13\u5b58\u670d\u52a1\u5668\u65f6\uff0c\u4e00\u79cd\u5e38\u7528\u7684\u8d1f\u8f7d\u5747\u8861\u65b9\u5f0f\u662f\uff0c\u5bf9\u8d44\u6e90o\u7684\u8bf7\u6c42\u4f7f\u7528<img decoding=\"async\" class=\"mwe-math-fallback-image-inline tex\" src=\"https:\/\/upload.wikimedia.org\/math\/8\/b\/6\/8b64bfff7ae85578d967e771bc3047aa.png\" alt=\"\\mbox{hash}(o) = o \\mod n\" \/>\u6765\u6620\u5c04\u5230\u67d0\u4e00\u53f0\u7f13\u5b58\u670d\u52a1\u5668\u3002\u5f53\u589e\u52a0\u6216\u51cf\u5c11\u4e00\u53f0\u7f13\u5b58\u670d\u52a1\u5668\u65f6\u8fd9\u79cd\u65b9\u5f0f\u53ef\u80fd\u4f1a\u6539\u53d8\u6240\u6709\u8d44\u6e90\u5bf9\u5e94\u7684hash\u503c\uff0c\u4e5f\u5c31\u662f\u6240\u6709\u7684\u7f13\u5b58\u90fd\u5931\u6548\u4e86\uff0c\u8fd9\u4f1a\u4f7f\u5f97\u7f13\u5b58\u670d\u52a1\u5668\u5927\u91cf\u96c6\u4e2d\u5730\u5411\u539f\u59cb\u5185\u5bb9\u670d\u52a1\u5668\u66f4\u65b0\u7f13\u5b58\u3002\u56e0\u4e9b\u9700\u8981\u4e00\u81f4\u54c8\u5e0c\u7b97\u6cd5\u6765\u907f\u514d\u8fd9\u6837\u7684\u95ee\u9898\u3002 \u4e00\u81f4\u54c8\u5e0c\u5c3d\u53ef\u80fd\u4f7f\u540c\u4e00\u4e2a\u8d44\u6e90\u6620\u5c04\u5230\u540c\u4e00\u53f0\u7f13\u5b58\u670d\u52a1\u5668\u3002\u8fd9\u79cd\u65b9\u5f0f\u8981\u6c42\u589e\u52a0\u4e00\u53f0\u7f13\u5b58\u670d\u52a1\u5668\u65f6\uff0c\u65b0\u7684\u670d\u52a1\u5668\u5c3d\u91cf\u5206\u62c5\u5b58\u50a8\u5176\u4ed6\u6240\u6709\u670d\u52a1\u5668\u7684\u7f13\u5b58\u8d44\u6e90\u3002\u51cf\u5c11\u4e00\u53f0\u7f13\u5b58\u670d\u52a1\u5668\u65f6\uff0c\u5176\u4ed6\u6240\u6709\u670d\u52a1\u5668\u4e5f\u53ef\u4ee5\u5c3d\u91cf\u5206\u62c5\u5b58\u50a8\u5b83\u7684\u7f13\u5b58\u8d44\u6e90\u3002 \u4e00\u81f4\u54c8\u5e0c\u7b97\u6cd5\u7684\u4e3b\u8981\u601d\u60f3\u662f\u5c06\u6bcf\u4e2a\u7f13\u5b58\u670d\u52a1\u5668\u4e0e\u4e00\u4e2a\u6216\u591a\u4e2a\u54c8\u5e0c\u503c\u57df\u533a\u95f4\u5173\u8054\u8d77\u6765\uff0c\u5176\u4e2d\u533a\u95f4\u8fb9\u754c\u901a\u8fc7\u8ba1\u7b97\u7f13\u5b58\u670d\u52a1\u5668\u5bf9\u5e94\u7684\u54c8\u5e0c\u503c\u6765\u51b3\u5b9a\u3002\uff08\u5b9a\u4e49\u533a\u95f4\u7684\u54c8\u5e0c\u51fd\u6570\u4e0d\u4e00\u5b9a\u548c\u8ba1\u7b97\u7f13\u5b58\u670d\u52a1\u5668\u54c8\u5e0c\u503c\u7684\u51fd\u6570\u76f8\u540c\uff0c\u4f46\u662f\u4e24\u4e2a\u51fd\u6570\u7684\u8fd4\u56de\u503c\u7684\u8303\u56f4\u9700\u8981\u5339\u914d\u3002\uff09\u5982\u679c\u4e00\u4e2a\u7f13\u5b58\u670d\u52a1\u5668\u88ab\u79fb\u9664\uff0c\u5219\u5b83\u4f1a\u4ece\u5bf9\u5e94\u7684\u533a\u95f4\u4f1a\u88ab\u5e76\u5165\u5230\u90bb\u8fd1\u7684\u533a\u95f4\uff0c\u5176\u4ed6\u7684\u7f13\u5b58\u670d\u52a1\u5668\u4e0d\u9700\u8981\u4efb\u4f55\u6539\u53d8\u3002<\/p>\n<h2><span id=\".E5.AE.9E.E7.8E.B0\" class=\"mw-headline\">\u5b9e\u73b0<\/span><\/h2>\n<p>\u4e00\u81f4\u54c8\u5e0c\u5c06\u6bcf\u4e2a\u5bf9\u8c61\u6620\u5c04\u5230\u5706\u73af\u8fb9\u4e0a\u7684\u4e00\u4e2a\u70b9\uff0c\u7cfb\u7edf\u518d\u5c06\u53ef\u7528\u7684\u8282\u70b9\u673a\u5668\u6620\u5c04\u5230\u5706\u73af\u7684\u4e0d\u540c\u4f4d\u7f6e\u3002\u67e5\u627e\u67d0\u4e2a\u5bf9\u8c61\u5bf9\u5e94\u7684\u673a\u5668\u65f6\uff0c\u9700\u8981\u7528\u4e00\u81f4\u54c8\u5e0c\u7b97\u6cd5\u8ba1\u7b97\u5f97\u5230\u5bf9\u8c61\u5bf9\u5e94\u5706\u73af\u8fb9\u4e0a\u4f4d\u7f6e\uff0c\u6cbf\u7740\u5706\u73af\u8fb9\u4e0a\u67e5\u627e\u76f4\u5230\u9047\u5230\u67d0\u4e2a\u8282\u70b9\u673a\u5668\uff0c\u8fd9\u53f0\u673a\u5668\u5373\u4e3a\u5bf9\u8c61\u5e94\u8be5\u4fdd\u5b58\u7684\u4f4d\u7f6e\u3002 \u5f53\u5220\u9664\u4e00\u53f0\u8282\u70b9\u673a\u5668\u65f6\uff0c\u8fd9\u53f0\u673a\u5668\u4e0a\u4fdd\u5b58\u7684\u6240\u6709\u5bf9\u8c61\u90fd\u8981\u79fb\u52a8\u5230\u4e0b\u4e00\u53f0\u673a\u5668\u3002\u6dfb\u52a0\u4e00\u53f0\u673a\u5668\u5230\u5706\u73af\u8fb9\u4e0a\u67d0\u4e2a\u70b9\u65f6\uff0c\u8fd9\u4e2a\u70b9\u7684\u4e0b\u4e00\u53f0\u673a\u5668\u9700\u8981\u5c06\u8fd9\u4e2a\u8282\u70b9\u524d\u5bf9\u5e94\u7684\u5bf9\u8c61\u79fb\u52a8\u5230\u65b0\u673a\u5668\u4e0a\u3002 \u66f4\u6539\u5bf9\u8c61\u5728\u8282\u70b9\u673a\u5668\u4e0a\u7684\u5206\u5e03\u53ef\u4ee5\u901a\u8fc7\u8c03\u6574\u8282\u70b9\u673a\u5668\u7684\u4f4d\u7f6e\u6765\u5b9e\u73b0\u3002<\/p>\n<div><strong>\u73af\u5f62Hash\u7a7a\u95f4<\/strong><\/div>\n<div>\u6309\u7167\u5e38\u7528\u7684hash\u7b97\u6cd5\u6765\u5c06\u5bf9\u5e94\u7684key\u54c8\u5e0c\u5230\u4e00\u4e2a\u5177\u67092^32\u6b21\u65b9\u4e2a\u6876\u7684\u7a7a\u95f4\u4e2d\uff0c\u53730~(2^32)-1\u7684\u6570\u5b57\u7a7a\u95f4\u4e2d\u3002\u73b0\u5728\u6211\u4eec\u53ef\u4ee5\u5c06\u8fd9\u4e9b\u6570\u5b57\u5934\u5c3e\u76f8\u8fde\uff0c\u60f3\u8c61\u6210\u4e00\u4e2a\u95ed\u5408\u7684\u73af\u5f62\u3002\u5982\u4e0b\u56fe<\/div>\n<div>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0<a href=\"https:\/\/wangqf.com\/wp-content\/uploads\/2017\/03\/20140411000507734.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-311\" src=\"https:\/\/wangqf.com\/wp-content\/uploads\/2017\/03\/20140411000507734.png\" alt=\"\" width=\"183\" height=\"193\" \/><\/a><\/div>\n<div>\n<div><strong>\u628a\u6570\u636e\u901a\u8fc7\u4e00\u5b9a\u7684hash\u7b97\u6cd5\u5904\u7406\u540e\u6620\u5c04\u5230\u73af\u4e0a<\/strong><\/div>\n<div>\u73b0\u5728\u6211\u4eec\u5c06object1\u3001object2\u3001object3\u3001object4\u56db\u4e2a\u5bf9\u8c61\u901a\u8fc7\u7279\u5b9a\u7684Hash\u51fd\u6570\u8ba1\u7b97\u51fa\u5bf9\u5e94\u7684key\u503c\uff0c\u7136\u540e\u6563\u5217\u5230Hash\u73af\u4e0a\u3002\u5982\u4e0b\u56fe\uff1a<\/div>\n<div>\u00a0 \u00a0 Hash(object1) = key1\uff1b<\/div>\n<div>\u00a0 \u00a0 Hash(object2) = key2\uff1b<\/div>\n<div>\u00a0 \u00a0 Hash(object3) = key3\uff1b<\/div>\n<div>\u00a0 \u00a0 Hash(object4) = key4\uff1b<\/div>\n<div>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0<a href=\"https:\/\/wangqf.com\/wp-content\/uploads\/2017\/03\/20140411000620656.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-312\" src=\"https:\/\/wangqf.com\/wp-content\/uploads\/2017\/03\/20140411000620656-300x280.png\" alt=\"\" width=\"300\" height=\"280\" \/><\/a><\/div>\n<div>\n<div><strong>\u5c06\u673a\u5668\u901a\u8fc7hash\u7b97\u6cd5\u6620\u5c04\u5230\u73af\u4e0a<\/strong><\/div>\n<div>\u5728\u91c7\u7528\u4e00\u81f4\u6027\u54c8\u5e0c\u7b97\u6cd5\u7684\u5206\u5e03\u5f0f\u96c6\u7fa4\u4e2d\u5c06\u65b0\u7684\u673a\u5668\u52a0\u5165\uff0c\u5176\u539f\u7406\u662f\u901a\u8fc7\u4f7f\u7528\u4e0e\u5bf9\u8c61\u5b58\u50a8\u4e00\u6837\u7684Hash\u7b97\u6cd5\u5c06\u673a\u5668\u4e5f\u6620\u5c04\u5230\u73af\u4e2d\uff08\u4e00\u822c\u60c5\u51b5\u4e0b\u5bf9\u673a\u5668\u7684hash\u8ba1\u7b97\u662f\u91c7\u7528\u673a\u5668\u7684IP\u6216\u8005\u673a\u5668\u552f\u4e00\u7684\u522b\u540d\u4f5c\u4e3a\u8f93\u5165\u503c\uff09\uff0c\u7136\u540e\u4ee5\u987a\u65f6\u9488\u7684\u65b9\u5411\u8ba1\u7b97\uff0c\u5c06\u6240\u6709\u5bf9\u8c61\u5b58\u50a8\u5230\u79bb\u81ea\u5df1\u6700\u8fd1\u7684\u673a\u5668\u4e2d\u3002<\/div>\n<div>\u5047\u8bbe\u73b0\u5728\u6709NODE1\uff0cNODE2\uff0cNODE3\u4e09\u53f0\u673a\u5668\uff0c\u901a\u8fc7Hash\u7b97\u6cd5\u5f97\u5230\u5bf9\u5e94\u7684KEY\u503c\uff0c\u6620\u5c04\u5230\u73af\u4e2d\uff0c\u5176\u793a\u610f\u56fe\u5982\u4e0b\uff1a<\/div>\n<div>Hash(NODE1) = KEY1;<\/div>\n<div>Hash(NODE2) = KEY2;<\/div>\n<div>Hash(NODE3) = KEY3;<\/div>\n<div>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0<a href=\"https:\/\/wangqf.com\/wp-content\/uploads\/2017\/03\/20140411000853609.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-313\" src=\"https:\/\/wangqf.com\/wp-content\/uploads\/2017\/03\/20140411000853609-300x278.png\" alt=\"\" width=\"300\" height=\"278\" \/><\/a><\/div>\n<div>\n<div>\u901a\u8fc7\u4e0a\u56fe\u53ef\u4ee5\u770b\u51fa\u5bf9\u8c61\u4e0e\u673a\u5668\u5904\u4e8e\u540c\u4e00\u54c8\u5e0c\u7a7a\u95f4\u4e2d\uff0c\u8fd9\u6837\u6309\u987a\u65f6\u9488\u8f6c\u52a8object1\u5b58\u50a8\u5230\u4e86NODE1\u4e2d\uff0cobject3\u5b58\u50a8\u5230\u4e86NODE2\u4e2d\uff0cobject2\u3001object4\u5b58\u50a8\u5230\u4e86NODE3\u4e2d\u3002\u5728\u8fd9\u6837\u7684\u90e8\u7f72\u73af\u5883\u4e2d\uff0chash\u73af\u662f\u4e0d\u4f1a\u53d8\u66f4\u7684\uff0c\u56e0\u6b64\uff0c\u901a\u8fc7\u7b97\u51fa\u5bf9\u8c61\u7684hash\u503c\u5c31\u80fd\u5feb\u901f\u7684\u5b9a\u4f4d\u5230\u5bf9\u5e94\u7684\u673a\u5668\u4e2d\uff0c\u8fd9\u6837\u5c31\u80fd\u627e\u5230\u5bf9\u8c61\u771f\u6b63\u7684\u5b58\u50a8\u4f4d\u7f6e\u4e86\u3002<\/div>\n<div><\/div>\n<div><strong>\u673a\u5668\u7684\u5220\u9664\u4e0e\u6dfb\u52a0<\/strong><\/div>\n<div>\u666e\u901ahash\u6c42\u4f59\u7b97\u6cd5\u6700\u4e3a\u4e0d\u59a5\u7684\u5730\u65b9\u5c31\u662f\u5728\u6709\u673a\u5668\u7684\u6dfb\u52a0\u6216\u8005\u5220\u9664\u4e4b\u540e\u4f1a\u7167\u6210\u5927\u91cf\u7684\u5bf9\u8c61\u5b58\u50a8\u4f4d\u7f6e\u5931\u6548\uff0c\u8fd9\u6837\u5c31\u5927\u5927\u7684\u4e0d\u6ee1\u8db3\u5355\u8c03\u6027\u4e86\u3002\u4e0b\u9762\u6765\u5206\u6790\u4e00\u4e0b\u4e00\u81f4\u6027\u54c8\u5e0c\u7b97\u6cd5\u662f\u5982\u4f55\u5904\u7406\u7684\u3002<\/div>\n<div>1. \u8282\u70b9\uff08\u673a\u5668\uff09\u7684\u5220\u9664<\/div>\n<div>\u00a0 \u00a0 \u4ee5\u4e0a\u9762\u7684\u5206\u5e03\u4e3a\u4f8b\uff0c\u5982\u679cNODE2\u51fa\u73b0\u6545\u969c\u88ab\u5220\u9664\u4e86\uff0c\u90a3\u4e48\u6309\u7167\u987a\u65f6\u9488\u8fc1\u79fb\u7684\u65b9\u6cd5\uff0cobject3\u5c06\u4f1a\u88ab\u8fc1\u79fb\u5230NODE3\u4e2d\uff0c\u8fd9\u6837\u4ec5\u4ec5\u662fobject3\u7684\u6620\u5c04\u4f4d\u7f6e\u53d1\u751f\u4e86\u53d8\u5316\uff0c\u5176\u5b83\u7684\u5bf9\u8c61\u6ca1\u6709\u4efb\u4f55\u7684\u6539\u52a8\u3002\u5982\u4e0b\u56fe\uff1a<\/div>\n<div>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0<a href=\"https:\/\/wangqf.com\/wp-content\/uploads\/2017\/03\/20140411001033656.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-314\" src=\"https:\/\/wangqf.com\/wp-content\/uploads\/2017\/03\/20140411001033656-300x281.png\" alt=\"\" width=\"300\" height=\"281\" \/><\/a><\/div>\n<div>\n<div>2. \u8282\u70b9\uff08\u673a\u5668\uff09\u7684\u6dfb\u52a0<\/div>\n<div>\u00a0 \u00a0 \u5982\u679c\u5f80\u96c6\u7fa4\u4e2d\u6dfb\u52a0\u4e00\u4e2a\u65b0\u7684\u8282\u70b9NODE4\uff0c\u901a\u8fc7\u5bf9\u5e94\u7684\u54c8\u5e0c\u7b97\u6cd5\u5f97\u5230KEY4\uff0c\u5e76\u6620\u5c04\u5230\u73af\u4e2d\uff0c\u5982\u4e0b\u56fe\uff1a<\/div>\n<div>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0<a href=\"https:\/\/wangqf.com\/wp-content\/uploads\/2017\/03\/20140411001211062.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-315\" src=\"https:\/\/wangqf.com\/wp-content\/uploads\/2017\/03\/20140411001211062-300x258.png\" alt=\"\" width=\"300\" height=\"258\" \/><\/a><\/div>\n<div>\n<div>\u00a0 \u00a0 \u901a\u8fc7\u6309\u987a\u65f6\u9488\u8fc1\u79fb\u7684\u89c4\u5219\uff0c\u90a3\u4e48object2\u88ab\u8fc1\u79fb\u5230\u4e86NODE4\u4e2d\uff0c\u5176\u5b83\u5bf9\u8c61\u8fd8\u4fdd\u6301\u8fd9\u539f\u6709\u7684\u5b58\u50a8\u4f4d\u7f6e\u3002\u901a\u8fc7\u5bf9\u8282\u70b9\u7684\u6dfb\u52a0\u548c\u5220\u9664\u7684\u5206\u6790\uff0c\u4e00\u81f4\u6027\u54c8\u5e0c\u7b97\u6cd5\u5728\u4fdd\u6301\u4e86\u5355\u8c03\u6027\u7684\u540c\u65f6\uff0c\u8fd8\u662f\u6570\u636e\u7684\u8fc1\u79fb\u8fbe\u5230\u4e86\u6700\u5c0f\uff0c\u8fd9\u6837\u7684\u7b97\u6cd5\u5bf9\u5206\u5e03\u5f0f\u96c6\u7fa4\u6765\u8bf4\u662f\u975e\u5e38\u5408\u9002\u7684\uff0c\u907f\u514d\u4e86\u5927\u91cf\u6570\u636e\u8fc1\u79fb\uff0c\u51cf\u5c0f\u4e86\u670d\u52a1\u5668\u7684\u7684\u538b\u529b\u3002<\/div>\n<div><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<pre><span style=\"color: #2e8b57;\"><b>template<\/b><\/span>\u00a0&lt;<span style=\"color: #2e8b57;\"><b>class<\/b><\/span>\u00a0Node, <span style=\"color: #2e8b57;\"><b>class<\/b><\/span>\u00a0Data, <span style=\"color: #2e8b57;\"><b>class<\/b><\/span>\u00a0Hash = HASH_NAMESPACE::hash&lt;<span style=\"color: #2e8b57;\"><b>const<\/b><\/span>\u00a0<span style=\"color: #2e8b57;\"><b>char<\/b><\/span>*&gt; &gt;\n<span style=\"color: #2e8b57;\"><b>class<\/b><\/span>\u00a0HashRing\n{\n<span style=\"color: #804040;\"><b>public<\/b><\/span>:\n\u00a0\u00a0\u00a0\u00a0<span style=\"color: #2e8b57;\"><b>typedef<\/b><\/span>\u00a0std::map&lt;<span style=\"color: #2e8b57;\"><b>size_t<\/b><\/span>, Node&gt; NodeMap;\n\n\u00a0\u00a0\u00a0\u00a0HashRing(<span style=\"color: #2e8b57;\"><b>unsigned<\/b><\/span>\u00a0<span style=\"color: #2e8b57;\"><b>int<\/b><\/span>\u00a0replicas)\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0: replicas_(replicas), hash_(HASH_NAMESPACE::hash&lt;<span style=\"color: #2e8b57;\"><b>const<\/b><\/span>\u00a0<span style=\"color: #2e8b57;\"><b>char<\/b><\/span>*&gt;())\n\u00a0\u00a0\u00a0\u00a0{\n\u00a0\u00a0\u00a0\u00a0}\n\n\u00a0\u00a0\u00a0\u00a0HashRing(<span style=\"color: #2e8b57;\"><b>unsigned<\/b><\/span>\u00a0<span style=\"color: #2e8b57;\"><b>int<\/b><\/span>\u00a0replicas, <span style=\"color: #2e8b57;\"><b>const<\/b><\/span>\u00a0Hash&amp; hash)\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0: replicas_(replicas), hash_(hash)\n\u00a0\u00a0\u00a0\u00a0{\n\u00a0\u00a0\u00a0\u00a0}\n\n\u00a0\u00a0\u00a0\u00a0<span style=\"color: #2e8b57;\"><b>size_t<\/b><\/span>\u00a0AddNode(<span style=\"color: #2e8b57;\"><b>const<\/b><\/span>\u00a0Node&amp; node);\n\u00a0\u00a0\u00a0\u00a0<span style=\"color: #2e8b57;\"><b>void<\/b><\/span>\u00a0RemoveNode(<span style=\"color: #2e8b57;\"><b>const<\/b><\/span>\u00a0Node&amp; node);\n\u00a0\u00a0\u00a0\u00a0<span style=\"color: #2e8b57;\"><b>const<\/b><\/span>\u00a0Node&amp; GetNode(<span style=\"color: #2e8b57;\"><b>const<\/b><\/span>\u00a0Data&amp; data) <span style=\"color: #2e8b57;\"><b>const<\/b><\/span>;\n\n<span style=\"color: #804040;\"><b>private<\/b><\/span>:\n\u00a0\u00a0\u00a0\u00a0NodeMap ring_;\n\u00a0\u00a0\u00a0\u00a0<span style=\"color: #2e8b57;\"><b>const<\/b><\/span>\u00a0<span style=\"color: #2e8b57;\"><b>unsigned<\/b><\/span>\u00a0<span style=\"color: #2e8b57;\"><b>int<\/b><\/span>\u00a0replicas_;\n\u00a0\u00a0\u00a0\u00a0Hash hash_;\n};\n\n<span style=\"color: #2e8b57;\"><b>template<\/b><\/span>\u00a0&lt;<span style=\"color: #2e8b57;\"><b>class<\/b><\/span>\u00a0Node, <span style=\"color: #2e8b57;\"><b>class<\/b><\/span>\u00a0Data, <span style=\"color: #2e8b57;\"><b>class<\/b><\/span>\u00a0Hash&gt;\n<span style=\"color: #2e8b57;\"><b>size_t<\/b><\/span>\u00a0HashRing&lt;Node, Data, Hash&gt;::AddNode(<span style=\"color: #2e8b57;\"><b>const<\/b><\/span>\u00a0Node&amp; node)\n{\n\u00a0\u00a0\u00a0\u00a0<span style=\"color: #2e8b57;\"><b>size_t<\/b><\/span>\u00a0hash;\n\u00a0\u00a0\u00a0\u00a0std::string nodestr = Stringify(node);\n\u00a0\u00a0\u00a0\u00a0<span style=\"color: #804040;\"><b>for<\/b><\/span>\u00a0(<span style=\"color: #2e8b57;\"><b>unsigned<\/b><\/span>\u00a0<span style=\"color: #2e8b57;\"><b>int<\/b><\/span>\u00a0r = <span style=\"color: #ff00ff;\">0<\/span>; r &lt; replicas_; r++) {\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0hash = hash_((nodestr + Stringify(r)).c_str());\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ring_[hash] = node;\n\u00a0\u00a0\u00a0\u00a0}\n\u00a0\u00a0\u00a0\u00a0<span style=\"color: #804040;\"><b>return<\/b><\/span>\u00a0hash;\n}\n\n<span style=\"color: #2e8b57;\"><b>template<\/b><\/span>\u00a0&lt;<span style=\"color: #2e8b57;\"><b>class<\/b><\/span>\u00a0Node, <span style=\"color: #2e8b57;\"><b>class<\/b><\/span>\u00a0Data, <span style=\"color: #2e8b57;\"><b>class<\/b><\/span>\u00a0Hash&gt;\n<span style=\"color: #2e8b57;\"><b>void<\/b><\/span>\u00a0HashRing&lt;Node, Data, Hash&gt;::RemoveNode(<span style=\"color: #2e8b57;\"><b>const<\/b><\/span>\u00a0Node&amp; node)\n{\n\u00a0\u00a0\u00a0\u00a0std::string nodestr = Stringify(node);\n\u00a0\u00a0\u00a0\u00a0<span style=\"color: #804040;\"><b>for<\/b><\/span>\u00a0(<span style=\"color: #2e8b57;\"><b>unsigned<\/b><\/span>\u00a0<span style=\"color: #2e8b57;\"><b>int<\/b><\/span>\u00a0r = <span style=\"color: #ff00ff;\">0<\/span>; r &lt; replicas_; r++) {\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span style=\"color: #2e8b57;\"><b>size_t<\/b><\/span>\u00a0hash = hash_((nodestr + Stringify(r)).c_str());\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ring_.erase(hash);\n\u00a0\u00a0\u00a0\u00a0}\n}\n\n<span style=\"color: #2e8b57;\"><b>template<\/b><\/span>\u00a0&lt;<span style=\"color: #2e8b57;\"><b>class<\/b><\/span>\u00a0Node, <span style=\"color: #2e8b57;\"><b>class<\/b><\/span>\u00a0Data, <span style=\"color: #2e8b57;\"><b>class<\/b><\/span>\u00a0Hash&gt;\n<span style=\"color: #2e8b57;\"><b>const<\/b><\/span>\u00a0Node&amp; HashRing&lt;Node, Data, Hash&gt;::GetNode(<span style=\"color: #2e8b57;\"><b>const<\/b><\/span>\u00a0Data&amp; data) <span style=\"color: #2e8b57;\"><b>const<\/b><\/span>\n{\n\u00a0\u00a0\u00a0\u00a0<span style=\"color: #804040;\"><b>if<\/b><\/span>\u00a0(ring_.empty()) {\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span style=\"color: #804040;\"><b>throw<\/b><\/span>\u00a0EmptyRingException();\n\u00a0\u00a0\u00a0\u00a0}\n\u00a0\u00a0\u00a0\u00a0<span style=\"color: #2e8b57;\"><b>size_t<\/b><\/span>\u00a0hash = hash_(Stringify(data).c_str());\n\u00a0\u00a0\u00a0\u00a0<span style=\"color: #2e8b57;\"><b>typename<\/b><\/span>\u00a0NodeMap::const_iterator it;\n\u00a0\u00a0\u00a0\u00a0<span style=\"color: #0000ff;\">\/\/ Look for the first node &gt;= hash<\/span>\n\u00a0\u00a0\u00a0\u00a0it = ring_.lower_bound(hash);\n\u00a0\u00a0\u00a0\u00a0<span style=\"color: #804040;\"><b>if<\/b><\/span>\u00a0(it == ring_.end()) {\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span style=\"color: #0000ff;\">\/\/ Wrapped around; get the first node<\/span>\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0it = ring_.begin();\n\u00a0\u00a0\u00a0\u00a0}\n\u00a0\u00a0\u00a0\u00a0<span style=\"color: #804040;\"><b>return<\/b><\/span>\u00a0it-&gt;second;\n}<\/pre>\n<p>&nbsp;<\/p>\n<h2><span id=\".E7.89.B9.E6.80.A7\" class=\"mw-headline\">\u7279\u6027<\/span><\/h2>\n<p>David Karger\u53ca\u5176\u5408\u4f5c\u8005\u5217\u51fa\u4e86\u4f7f\u5f97\u4e00\u81f4\u54c8\u5e0c\u5728\u4e92\u8054\u7f51\u5206\u5e03\u5f0f\u7f13\u5b58\u4e2d\u975e\u5e38\u6709\u7528\u7684\u51e0\u4e2a\u7279\u6027\uff1a<\/p>\n<ul>\n<li>\u5197\u4f59\u5c11<\/li>\n<li>\u8d1f\u8f7d\u5747\u8861<\/li>\n<li>\u8fc7\u6e21\u5e73\u6ed1<\/li>\n<li>\u5b58\u50a8\u5747\u8861<\/li>\n<li>\u5173\u952e\u8bcd\u5355\u8c03<\/li>\n<\/ul>\n<h2>\u95ee\u9898<\/h2>\n<p>\u4e0a\u8fb9\u63cf\u8ff0\u7684\u4e00\u81f4\u6027Hash\u7b97\u6cd5\u6709\u4e2a\u6f5c\u5728\u7684\u95ee\u9898\u662f:<br \/>\n\u5c06\u8282\u70b9hash\u540e\u4f1a\u4e0d\u5747\u5300\u5730\u5206\u5e03\u5728\u73af\u4e0a\uff0c\u8fd9\u6837\u5927\u91cfkey\u5728\u5bfb\u627e\u8282\u70b9\u65f6\uff0c\u4f1a\u5b58\u5728key\u547d\u4e2d\u5404\u4e2a\u8282\u70b9\u7684\u6982\u7387\u5dee\u522b\u8f83\u5927\uff0c\u65e0\u6cd5\u5b9e\u73b0\u6709\u6548\u7684\u8d1f\u8f7d\u5747\u8861\u3002\u53ef\u4ee5\u4f7f\u7528\u865a\u62df\u8282\u70b9\u7684\u601d\u60f3\uff0c\u4e3a\u6bcf\u4e2a\u7269\u7406\u8282\u70b9\uff08\u670d\u52a1\u5668\uff09\u5728\u5706\u4e0a\u5206\u914d100\uff5e200\u4e2a\u70b9\u3002\u8fd9\u6837\u5c31\u80fd\u6291\u5236\u5206\u5e03\u4e0d\u5747\u5300\uff0c\u6700\u5927\u9650\u5ea6\u5730\u51cf\u5c0f\u670d\u52a1\u5668\u589e\u51cf\u65f6\u7684\u7f13\u5b58\u91cd\u65b0\u5206\u5e03\u3002\u7528\u6237\u6570\u636e\u6620\u5c04\u5728\u865a\u62df\u8282\u70b9\u4e0a\uff0c\u5c31\u8868\u793a\u7528\u6237\u6570\u636e\u771f\u6b63\u5b58\u50a8\u4f4d\u7f6e\u662f\u5728\u8be5\u865a\u62df\u8282\u70b9\u4ee3\u8868\u7684\u5b9e\u9645\u7269\u7406\u670d\u52a1\u5668\u4e0a\u3002<\/p>\n<p>&nbsp;<\/p>\n<h3>\u53c2\u8003\u6587\u732e<\/h3>\n<ol>\n<li><a href=\"https:\/\/zh.wikipedia.org\/wiki\/%E4%B8%80%E8%87%B4%E5%93%88%E5%B8%8C#cite_note-KargerEtAl1999-2\">\u4e00\u81f4\u54c8\u5e0c<\/a><\/li>\n<li style=\"text-align: left;\"><a href=\"http:\/\/blog.csdn.net\/cywosp\/article\/details\/23397179\">\u6bcf\u5929\u8fdb\u6b65\u4e00\u70b9\u70b9\u2014\u2014\u4e94\u5206\u949f\u7406\u89e3\u4e00\u81f4\u6027\u54c8\u5e0c\u7b97\u6cd5(consistent hashing)<\/a><\/li>\n<li style=\"text-align: left;\"><a href=\"http:\/\/get.ftqq.com\/7057.get\">memcache\u7684\u4e00\u81f4\u6027hash\u7b97\u6cd5\u4f7f\u7528<\/a><\/li>\n<li style=\"text-align: left;\"><a href=\"http:\/\/www.martinbroadhurst.com\/Consistent-Hash-Ring.html\">Consistent Hash Ring<\/a><\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>\u5728\u5206\u5e03\u5f0f\u7f13\u5b58\u548c\u5206\u5e03\u5f0f\u5b58\u50a8\u7cfb\u7edf\u4e0a\u7ecf\u5e38\u7528\u5230\u4e00\u81f4\u6027\u54c8\u5e0c\u7b97\u6cd5\uff0c\u4eca\u5929\u7279\u5730\u6765\u5b66\u4e60\u4e00\u4e0b\u3002 \u4e00\u81f4\u54c8\u5e0c \u662f\u4e00\u79cd\u7279\u6b8a\u7684\u54c8\u5e0c\u7b97\u6cd5\u3002\u5728 &hellip; <a href=\"https:\/\/wangqf.com\/?p=151\" class=\"more-link\">\u7ee7\u7eed\u9605\u8bfb<span class=\"screen-reader-text\">\u201c\u4e00\u81f4\u6027\u54c8\u5e0c\u7b97\u6cd5\u201d<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-151","post","type-post","status-publish","format-standard","hentry","category-2"],"_links":{"self":[{"href":"https:\/\/wangqf.com\/index.php?rest_route=\/wp\/v2\/posts\/151","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wangqf.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wangqf.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wangqf.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wangqf.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=151"}],"version-history":[{"count":0,"href":"https:\/\/wangqf.com\/index.php?rest_route=\/wp\/v2\/posts\/151\/revisions"}],"wp:attachment":[{"href":"https:\/\/wangqf.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=151"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wangqf.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=151"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wangqf.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=151"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}