{"id":1065,"date":"2021-01-31T17:48:43","date_gmt":"2021-01-31T09:48:43","guid":{"rendered":"http:\/\/www.mrtblog.cn\/?p=1065"},"modified":"2023-03-12T16:15:48","modified_gmt":"2023-03-12T08:15:48","slug":"1065","status":"publish","type":"post","link":"http:\/\/www.mrtblog.cn\/?p=1065","title":{"rendered":"\u4e00\u81f4\u6027\u54c8\u5e0c\u7b97\u6cd5"},"content":{"rendered":"
<\/span> 4,662<\/span> Views<\/span><\/div>

\u5728\u4f7f\u7528\u4e00\u81f4\u6027\u54c8\u5e0c\u7b97\u6cd5\u4e4b\u524d\uff0c\u9996\u5148\u6211\u4eec\u8981\u660e\u786e\u8fd9\u4e2a\u7b97\u6cd5\u5230\u5e95\u662f\u7528\u6765\u505a\u4ec0\u4e48\u7684\uff0c\u4e3a\u4ec0\u4e48\u8981\u4f7f\u7528\u4e00\u81f4\u6027\u54c8\u5e0c\u800c\u4e0d\u4f7f\u7528\u5176\u4ed6\u7b97\u6cd5\u3002<\/p>\n

\u573a\u666f\uff1a<\/strong><\/p>\n

\u67094<\/strong><\/span>\u53f0\u670d\u52a1\u5668\u3002\u6bcf\u53f0\u670d\u52a1\u5668\u53ef\u4ee5\u63a5\u53d76<\/span><\/strong>\u4e2a\u7528\u6237\u8fde\u63a5\uff0c\u73b0\u5728\u670920<\/span><\/strong>\u4e2a\u7528\u6237\u60f3\u8981\u548c\u670d\u52a1\u5668\u8fdb\u884c\u901a\u4fe1\uff0c\u6211\u4eec\u8be5\u5982\u4f55\u5206\u914d\u7528\u6237\u5230\u4e0d\u540c\u7684\u670d\u52a1\u5668\u4e0a\uff1f<\/p>\n

\u76f4\u63a5\u53d6\u6a21\u7b97\u6cd5<\/h2>\n

\u7b2c\u4e00\u6b65\uff0c\u6211\u4eec\u4e3a\u670d\u52a1\u5668\u6807\u8bc6\u552f\u4e00\u7684ID\uff0c\u5047\u8bbe\u4ece0\u5f00\u59cb\uff0c\u5219svrid\u4e3a[0,3]<\/strong><\/p>\n

\u7b2c\u4e8c\u6b65\uff0c\u540c\u7406\u6211\u4eec\u4e3a\u6bcf\u4e00\u4e2a\u7528\u6237\u6807\u8bc6\u552f\u4e00ID\uff0c\u4ece0\u5f00\u59cb\u9012\u589e\uff0c\u5219\u7528\u6237\u7684id\u4e3a[0,19]<\/strong><\/p>\n

\u7b2c\u4e09\u6b65\uff0c\u6211\u4eec\u4f7f\u7528\u6700\u7b80\u5355\u7684\u53d6\u6a21\u7b97\u6cd5\uff0c\u5bf9id\u53d6\u6a214(\u7b49\u4e8e\u5b9e\u9645\u7684\u670d\u52a1\u5668\u6570\u91cf)\u540e\u5212\u5206\u5230\u4e0d\u540c\u7684\u670d\u52a1\u5668\u4e0a\uff0c\u53ef\u4ee5\u5f97\u5230\u4ee5\u4e0b\u7684\u5206\u914d\u5173\u7cfb\u8868<\/p>\n\n\n\n\n\n\n\n
SvrId<\/td>\nUserID<\/td>\n<\/tr>\n
0<\/td>\n0\u30014\u30018\u300112\u300116<\/td>\n<\/tr>\n
1<\/td>\n1\u30015\u30019\u300113\u300117<\/td>\n<\/tr>\n
2<\/td>\n2\u30016\u300110\u300114\u300118<\/td>\n<\/tr>\n
3<\/td>\n3\u30017\u300111\u300115\u300119<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u8fd9\u6837\u89e3\u51b3\u4e86\u670d\u52a1\u5668\u80fd\u5747\u5300\u7684\u63a5\u53d7\u7528\u6237\u8fde\u63a5\uff0c\u53ea\u9700\u8981\u4fdd\u8bc1\u7528\u6237\u7684userid\u662f\u5747\u5300\u5206\u5e03\u7684\uff0c<\/p>\n

\u4e3a\u4ec0\u4e48userid\u9700\u8981\u5747\u5300\u5206\u5e03\uff1f<\/h4>\n

\u53ef\u4ee5\u60f3\u8c61\u5982\u679cuserid\u662f\u4e0d\u5747\u5300\u7684\uff0c\u6bd4\u5982userid=[0\/4\/8\/12\/16\/20\/24\/28\/32\u2026.]\uff0c\u53d6\u6a21\u540e\u6240\u6709\u7684user\u90fd\u4f1a\u88ab\u5206\u5230svr0\u4e0a\uff0c\u9020\u6210\u5de8\u5927\u7684\u8d1f\u8f7d\u538b\u529b<\/p>\n

\u5982\u4f55\u6269\u5bb9\uff1f<\/h4>\n

\u73b0\u5728\u6211\u4eec\u56e0\u4e3a\u6b63\u5e38\u7684\u670d\u52a1\u5668\u53d8\u52a8\uff0c\u9700\u8981\u5c06\u670d\u52a1\u5668\u7684\u6570\u91cf\u4ece4->5\uff0c\u4ecd\u7136\u9700\u8981\u6ee1\u8db3\u7528\u6237\u5747\u5300\u7684\u5206\u914d\u5230\u5404\u4e2a\u670d\u52a1\u5668\u4e0a\uff0c\u6309\u7167\u4e0a\u8282\u7684\u53d6\u6a21\u65b9\u6cd5\u91cd\u65b0\u5efa\u7acb\u7684\u5206\u914d\u8868\u5982\u4e0b<\/p>\n\n\n\n\n\n\n\n\n
SvrId(\u670d\u52a1\u5668ID)<\/td>\nPre(\u6269\u5bb9\u524d\u5206\u914d\u72b6\u6001)<\/td>\nAft(\u6269\u5bb9\u540e\u5206\u914d\u72b6\u6001)<\/td>\n<\/tr>\n
0<\/td>\n0\u30014\u30018\u300112\u300116<\/td>\n0\u30015<\/span>\u300110<\/span>\u300115<\/span><\/td>\n<\/tr>\n
1<\/td>\n1\u30015\u30019\u300113\u300117<\/td>\n1\u30016<\/span>\u300111<\/span>\u300116<\/span><\/td>\n<\/tr>\n
2<\/td>\n2\u30016\u300110\u300114\u300118<\/td>\n2\u30017<\/span>\u300112<\/span>\u300117<\/span><\/td>\n<\/tr>\n
3<\/td>\n3\u30017\u300111\u300115\u300119<\/td>\n3\u30018<\/span>\u300113<\/span>\u300118<\/span><\/td>\n<\/tr>\n
4<\/td>\n<\/td>\n4<\/span>\u30019<\/span>\u300114<\/span>\u300119<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u663e\u7136\uff0c\u4e3a\u4e86\u6ee1\u8db3\u5206\u914d\u7684\u5747\u5300\u6027\uff0c\u6211\u4eec\u9700\u8981\u53d8\u52a8\u7684\u5206\u914d\u8282\u70b9\u4e3a16\u4e2a\uff0c\u5982\u679c\u5f53\u524d\u6240\u6709\u7528\u6237\u90fd\u5df2\u7ecf\u548c\u6269\u5bb9\u524d\u7684\u670d\u52a1\u5668\u5efa\u7acb\u4e86\u8fde\u63a5\uff0c\u90a3\u4e48\u8fd9\u4e00\u6b21\u6269\u5bb9\u4f1a\u5bfc\u81f480%(16\/20)<\/strong>\u7684\u7528\u6237\u51fa\u73b0\u65ad\u5f00\u8fde\u63a5\u5e76\u91cd\u65b0\u8fde\u63a5\u7684\u60c5\u51b5\uff0c\u8fd9\u4e2a\u5f00\u9500\u662f\u6211\u4eec\u6ca1\u6cd5\u5bb9\u5fcd\u7684<\/p>\n

\u4e3a\u4ec0\u4e48\u4e00\u5b9a\u8981\u65ad\u5f00\u8fde\u63a5\u7136\u540e\u91cd\u65b0\u8fde\u63a5\uff1f<\/h4>\n

\u5982\u679c\u4e0a\u8ff0\u7528\u6237\u8fde\u63a5\u5230\u670d\u52a1\u5668\u4fdd\u6301\u7684\u662fTCP\u7684\u957f\u8fde\u63a5\uff0c\u9700\u8981\u6301\u7eed\u505aDB\u5199\u5165\u7b49\u64cd\u4f5c\uff0c\u5c31\u5fc5\u987b\u7b49\u5f85\u6269\u5bb9\u524d\u8fde\u63a5\u7684\u670d\u52a1\u5668\u65ad\u5f00\u8fde\u63a5\u540e\uff0c\u518d\u91cd\u65b0\u5efa\u7acb\u8fde\u63a5\u5230\u65b0\u7684\u670d\u52a1\u5668\uff0c\u5426\u5219\u53ef\u80fd\u4f1a\u51fa\u73b0\u4e24\u53f0\u670d\u52a1\u5668\u5199\u5165\u540c\u4e00\u4e2aDB\u6570\u636e\uff0c\u6216\u8005\u4e00\u4e2a\u7528\u6237\u540c\u65f6\u8fde\u63a5\u5230\u4e24\u53f0\u670d\u52a1\u5668\u7684\u60c5\u51b5(\u8fd9\u663e\u7136\u8fdd\u80cc\u4e86\u4e00\u81f4\u6027\u539f\u5219)<\/p>\n

\u4ee3\u7801\u5b9e\u73b0<\/h4>\n

\u53d6\u6a21\u65b9\u6cd5\u867d\u7136\u6269\u5bb9\u5f00\u9500\u5927\uff0c\u4f46\u662f\u5b9e\u73b0\u975e\u5e38\u7b80\u5355\uff0c\u4e5f\u4e0d\u9700\u8981\u5b58\u50a8\u4efb\u4f55\u6570\u636e\uff0c\u6240\u6709\u7684\u7528\u6237\u5728\u5efa\u7acb\u8fde\u63a5\u65f6\u53ef\u4ee5\u901a\u8fc7\u63a5\u53e3\u76f4\u63a5\u77e5\u9053\u5e94\u8be5\u8fde\u63a5\u54ea\u4e2a\u670d\u52a1\u5668<\/p>\n

int GetSvrIDByUserID(int iUserID, int iSvrNum)\n{\n    if (iSvrNum == 0)\n    {\n        return 0;\n    }\n    return iUserID % iSvrNum;\n}<\/code><\/pre>\n
\u4e00\u81f4\u6027\u54c8\u5e0c\u7b97\u6cd5<\/h2>\n
\u628a\u6570\u636e\u7528hash\u51fd\u6570\uff08\u5982MD5\uff0cMurMurHash\u7b49\u7b97\u6cd5\uff09\uff0c\u628auserid\u6620\u5c04\u5230\u4e00\u4e2a\u5f88\u5927\u7684\u7a7a\u95f4\u91cc\uff0c\u627e\u5230\u79bb\u8be5\u6570\u636e\u843d\u5728\u7684\u4f4d\u7f6e\u6700\u8fd1\u7684\u4e0b\u4e00\u4e2a\u8282\u70b9\u4f5c\u4e3a\u5206\u914d\u8282\u70b9(\u7b80\u5355\u8d77\u89c1\u5c31\u4e0d\u753b20\u4e2auser\u8282\u70b9\u4e86)\"\"<\/a><\/p>\n
\u4f8b\u5982user0\/1\u88ab\u5206\u914d\u5230\u4e86svr1\uff0cuser2\/3\u5206\u914d\u5230\u4e86svr2\uff0c\u6709\u6269\u5bb9\u9700\u6c42\u65f6\uff0c\u6211\u4eec\u540c\u6837\u5c06\u65b0\u52a0\u5165\u7684\u8282\u70b9\u4f7f\u7528hash\u7b97\u6cd5\u63d2\u5165\u5230\u73af\u4e0a\uff0c\u8fd9\u6837\u53ea\u5f71\u54cdsvr\u63d2\u5165\u4f4d\u7f6e\u4e4b\u524d\u7684user\u8282\u70b9\u7684\u91cd\u5206\u914d\"\"<\/a><\/p>\n
\u6269\u5bb9\u524d\u540e\u7684\u5206\u914d\u5173\u7cfb\u5982\u4e0b<\/p>\n\n\n\n\n\n\n\n\n
SvrId(\u670d\u52a1\u5668ID)<\/td>\nPre(\u6269\u5bb9\u524d\u5206\u914d\u72b6\u6001)<\/td>\nAft(\u6269\u5bb9\u540e\u5206\u914d\u72b6\u6001)<\/td>\n<\/tr>\n
0<\/td>\n6<\/td>\n6<\/td>\n<\/tr>\n
1<\/td>\n0\u30011<\/td>\n0\u30011<\/td>\n<\/tr>\n
2<\/td>\n2\u30013<\/td>\n3<\/td>\n<\/tr>\n
3<\/td>\n4\u30015<\/td>\n4\u30015<\/td>\n<\/tr>\n
4(\u65b0\u589e)<\/span><\/td>\n<\/td>\n2<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\u5206\u914d\u4e0d\u5747<\/h4>\n
\u8fd9\u79cd\u505a\u6cd5\u7684\u660e\u663e\u5f0a\u7aef\u6709\u4e24\u4e2a\uff1a<\/p>\n
    \n
  1. \u6269\u5bb9\u65f6\u4f1a\u5b58\u5728\u67d0\u4e2asvr\u90e8\u5206\u6301\u6709\u8282\u70b9\u8f6c\u79fb\u5230\u65b0svr,\u5bfc\u81f4\u8fd9\u4e24\u4e2asvr\u7684\u6301\u6709\u8282\u70b9\u6570\u91cf\u76f8\u8f83\u4e8e\u5176\u4ed6svr\u660e\u663e\u4e0d\u5747\u5300<\/li>\n
  2. \u7f29\u5bb9\u65f6\u67d0\u4e00\u4e2asvr\u4ece\u73af\u4e0a\u64a4\u4e0b\uff0c\u5219\u8be5svr\u539f\u672c\u6301\u6709\u7684\u6240\u6709\u8282\u70b9\u5168\u90e8\u4ea4\u7ed9\u4e0b\u4e00\u4e2asvr\uff0c\u9020\u6210\u8be5svr\u8d1f\u8f7d\u4e24\u500d\u7684\u538b\u529b<\/li>\n<\/ol>\n
    \u865a\u62df\u8282\u70b9<\/h4>\n
    \u65e2\u7136\u628a\u5b9e\u9645\u7684svr\u8282\u70b9\u653e\u5728\u73af\u4e0a\u4e0d\u53ef\u53d6\uff0c\u6211\u4eec\u53ef\u4ee5\u5efa\u7acb\u865a\u62df\u8282\u70b9\u89e3\u51b3\u6269\u5bb9\u548c\u7f29\u5bb9\u65f6\u51fa\u73b0\u7684\u5206\u914d\u4e0d\u5747\u95ee\u9898(\u5047\u8bbe\u73b0\u5728\u6211\u4eec\u4e3a\u6bcf\u4e2a\u5b9e\u9645\u7684\u670d\u52a1\u5668\u51c6\u59072<\/strong>\u4e2a\u865a\u62df\u8282\u70b9)
    \n\"\"<\/a><\/p>\n
    \u6269\u5bb9\u7684\u60c5\u51b5\u548c\u4e0d\u8bbe\u7f6e\u865a\u62df\u8282\u70b9\u7684\u65b9\u6cd5\u7c7b\u4f3c\uff0c\u6211\u4eec\u770b\u7f29\u5bb9\u7684\u60c5\u51b5\uff0c\u5047\u8bbe\u9700\u8981\u5c06svr0\u4ece\u73af\u4e2d\u53d6\u51fa\uff0cuser\u8282\u70b9\u5728\u7f29\u5bb9\u524d\u540e\u7684\u5206\u914d\u5173\u7cfb\u4e3a<\/p>\n\n\n\n\n\n\n\n
    SvrId(\u670d\u52a1\u5668ID)<\/td>\nPre(\u7f29\u5bb9\u524d\u5206\u914d\u72b6\u6001)<\/td>\nAft(\u7f29\u5bb9\u540e\u5206\u914d\u72b6\u6001)<\/td>\n<\/tr>\n
    0(\u79fb\u9664)<\/span><\/td>\n6\u30012<\/td>\n<\/td>\n<\/tr>\n
    1<\/td>\n1\u30014<\/td>\n1\u30014<\/td>\n<\/tr>\n
    2<\/td>\n3<\/td>\n3\u30012<\/span><\/td>\n<\/tr>\n
    3<\/td>\n0\u30015<\/td>\n0\u30015\u30016<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    \u5c3d\u7ba1\u53ef\u80fd\u8fd8\u662f\u5b58\u5728\u5206\u914d\u4e0d\u5e73\u8861\uff0c\u4f46\u662f\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u7ee7\u7eed\u589e\u52a0\u865a\u62df\u8282\u70b9\u6765\u7f13\u89e3\u5206\u5e03\u4e0d\u5747\u7684\u95ee\u9898<\/p>\n
    \u4ee3\u7801\u5b9e\u73b0<\/h4>\n
    \u56e0\u4e3a\u6709\u865a\u62df\u8282\u70b9\u7684\u6982\u5ff5\uff0c\u6211\u4eec\u5fc5\u987b\u8981\u7ef4\u62a4\u4e00\u4e2a\u865a\u62df\u8282\u70b9-\u771f\u5b9e\u670d\u52a1\u5668\u7684\u6620\u5c04\u5173\u7cfb\uff0c\u5e76\u4e14\u5728\u6269\u7f29\u5bb9\u7684\u65f6\u5019\u4fee\u6539\u5b83<\/p>\n
    class ConsistentHash\n{\npublic:\n    ConsistentHash(int iRealNodeNum, int iVirtualNodeNum);\n\n\n    int GetSvrIDByUserID(uint64_t userID);\n    int HashKey(uint64_t);\n    void DelNode(int iSvrID);\n    void AddNode(int iSvrID);\n    int GetNodeKey(int iRealID, int iVirtualID);\n\nprivate:\n    std::map<int, int> m_stServerNode; \/\/\u865a\u62df\u8282\u70b9\u548c\u771f\u5b9e\u673a\u5668ID\u7684\u5bf9\u5e94\u5173\u7cfb\n    int m_stVirtualNodeNum;\/\/\u6bcf\u4e00\u4e2a\u771f\u5b9e\u673a\u5668\u62e5\u6709\u7684\u865a\u62df\u8282\u70b9\u6570\u91cf\n};\nint ConsistentHash::GetNodeKey(int iRealID, int iVirtualID)\n{\n    return iRealID * 100000 + iVirtualID;\n}\nConsistentHash::ConsistentHash(int iRealNodeNum, int iVirtualNodeNum)\n{\n    m_stServerNode.clear();\n    m_stVirtualNodeNum = iVirtualNodeNum;\n    \/\/\u6709iRealNodeNum\u771f\u5b9e\u670d\u52a1\u5668\u8282\u70b9\n    for (int i = 0; i < iRealNodeNum; ++i)\n    {\n        \/\/\u6bcf\u4e2a\u771f\u5b9e\u8282\u70b9\u90fd\u6709iVirtualNodeNum\u4e2a\u865a\u62df\u8282\u70b9\n        for (int j = 0; j < iVirtualNodeNum; ++j)\n        {\n            \/\/\u8fd9\u91cc\u5c06\u7b2ci\u4e2a\u771f\u5b9e\u673a\u5668\u7684\u7b2cj\u4e2a\u865a\u62df\u8282\u70b9\u8f6c\u6362\u6210\u4e00\u4e2aint\u7c7b\u578b\u7684key,\n            \/\/\u600e\u4e48\u8f6c\u6362\u6309\u5b9e\u9645\u9700\u6c42\u6765\uff0c\u7b80\u5355\u8d77\u89c1\u8fd9\u4e2a\u51fd\u6570\u5c31\u662f\u505a\u4e86\u4e0b\u504f\u79fb\n            int key = GetNodeKey(i, j);\n            \/\/\u865a\u62df\u8282\u70b9\u5bf9\u5e94\u5230\u54ea\u4e2a\u771f\u5b9e\u670d\u52a1\u5668\n            m_stServerNode[key] = i;\n        }\n    }\n}\n\/\/\u6269\u5bb9\nvoid ConsistentHash::AddNode(int iSvrID)\n{\n    for (int j = 0; j < m_stVirtualNodeNum; ++j)\n    {\n        int key = GetNodeKey(iSvrID, j);\n        m_stServerNode[key] = iSvrID;\n    }\n}\n\/\/\u7f29\u5bb9\nvoid ConsistentHash::DelNode(int iSvrID)\n{\n    for (int j = 0; j < m_stVirtualNodeNum; ++j)\n    {\n        int key = GetNodeKey(iSvrID, j);\n        m_stServerNode.erase(key);\n    }\n}\nint ConsistentHash::HashKey(uint64_t uUserID)\n{\n    return (uUserID << 1) % 100000;\n}\nint ConsistentHash::GetSvrIDByUserID(uint64_t userID)\n{\n    \/\/\u8fd9\u91cc\u4e5f\u662f\u6839\u636e\u9700\u8981,\u81ea\u5df1\u505a\u51fauserid\u5230\u54c8\u5e0c\u73af\u4e0a\u4f4d\u7f6e\u7684\u6620\u5c04\n    int key = HashKey(userID);\n    map<int, int>::iterator it = m_stServerNode.lower_bound(key);\/\/\u627e\u5230\u865a\u62df\u8282\u70b9\n    \/\/\u672a\u627e\u5230\n    if (it == m_stServerNode.end())\n    {\n        return m_stServerNode.begin()->second;\n    }\n    \/\/\u627e\u5230\u4e86\n    return it->second;\n}<\/code><\/pre>\n
    jump consistent hash<\/h2>\n
    \u4e00\u81f4\u6027\u54c8\u5e0c\u7b97\u6cd5\u7684\u865a\u62df\u8282\u70b9\u5904\u7406\u4e0a\u6709\u4e9b\u590d\u6742\u4e86\uff0c\u8fd8\u662f\u56de\u5230\u4e4b\u524d\u7684\u95ee\u9898\uff0c\u6211\u4eec\u5c31\u60f3\u4f9d\u9760\u771f\u5b9e\u7684\u670d\u52a1\u5668\u8282\u70b9\uff0c\u4ece4\u53f0\u6269\u5bb9\u52305\u53f0\uff0c\u4f46\u662f\u5c3d\u53ef\u80fd\u5747\u5300\u7684\u5206\u914d\u3002<\/p>\n
    \u4ece\u7ed3\u679c\u5206\u6790\uff0c\u6269\u5bb9\u524d4\u53f0svr\u6bcf\u53f0\u5e73\u5747\u6301\u67095\u4e2a\u8282\u70b9->\u6269\u5bb9\u540e5\u53f0svr\u6bcf\u53f0\u5e73\u5747\u6301\u67094\u4e2a\u8282\u70b9\uff0c\u6269\u5bb9\u8fc7\u7a0b\u4e2d\u6211\u4eec\u8981\u505a\u7684\u662f\u4ece\u539f\u5148\u5df2\u7ecf\u5206\u914d\u768420\u4e2a\u8282\u70b9\u4e2d\u9009\u51fa4\u4e2a\u8f6c\u79fb\u5230\u65b0\u589e\u7684\u7b2c5\u53f0svr\u4e0a<\/p>\n
    \u968f\u673a\u91cd\u5206\u914d<\/h4>\n
    \u57fa\u4e8e\u5df2\u7ecf\u5206\u914d\u597d\u7684\u8282\u70b9\uff0c\u6211\u4eec\u5bf9\u6bcf\u4e2a\u8282\u70b9\uff0c\u8ba9\u4ed6\u67094\/20\u7684\u6982\u7387\u91cd\u65b0\u5206\u914d\u5230\u65b0\u7684svr\u4e0a\u5c31\u597d\u4e86(\u5047\u8bbe\u968f\u673a\u88ab\u9009\u4e2d\u7684\u8282\u70b9\u662f7\/10\/13\/16)<\/p>\n\n\n\n\n\n\n\n\n
    SvrId(\u670d\u52a1\u5668ID)<\/td>\nPre(\u6269\u5bb9\u524d\u5206\u914d\u72b6\u6001)<\/td>\nAft(\u6269\u5bb9\u540e\u5206\u914d\u72b6\u6001)<\/td>\n<\/tr>\n
    0<\/td>\n0\u30014\u30018\u300112\u300116<\/td>\n0\u30014\u30018\u300112<\/td>\n<\/tr>\n
    1<\/td>\n1\u30015\u30019\u300113\u300117<\/td>\n1\u30015\u30019\u300117<\/td>\n<\/tr>\n
    2<\/td>\n2\u30016\u300110\u300114\u300118<\/td>\n2\u30016\u300114\u300118<\/td>\n<\/tr>\n
    3<\/td>\n3\u30017\u300111\u300115\u300119<\/td>\n3\u300111\u300115\u300119<\/td>\n<\/tr>\n
    4(\u65b0\u589e)<\/span><\/td>\n<\/td>\n7\u300110\u300113\u300116<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    \u8fd9\u6837\u6211\u4eec\u8f6c\u79fb\u8017\u8d39\u7684\u6210\u672c\u4e3a20%(4\/20)<\/strong>\uff0c\u5bf9\u5927\u591a\u6570\u7528\u6237\u90fd\u662f\u6ca1\u6709\u5f71\u54cd<\/p>\n
    \u4ee3\u7801\u5b9e\u73b0<\/h4>\n
    \u73b0\u5728\u6211\u4eec\u8003\u8651\u4ee3\u7801\u5982\u4f55\u8bbe\u8ba1\uff0c\u4fdd\u8bc1\u4e0d\u5360\u7528\u591a\u4f59\u7684\u5185\u5b58\uff0c\u4e14\u6269\u5bb9\u524d\u540e\u4e0d\u6539\u52a8\u4ee3\u7801<\/p>\n
      \n
    • \u9996\u5148\u5047\u8bbe\u53ea\u67091\u53f0svr\uff0c\u6b64\u65f6\u6240\u6709\u8282\u70b9\u90fd\u88ab\u653e\u5728svr0\u4e0a<\/li>\n
    • svr\u589e\u52a0\u52302\u53f0\u540e\uff0c\u6bcf\u4e00\u4e2auserid\u90fd\u67091\/2\u7684\u6982\u7387\u88ab\u5206\u5230svr1\u4e0a<\/li>\n
    • svr\u589e\u52a0\u52303\u53f0\u540e\uff0c\u6bcf\u4e00\u4e2auserid\u5728\u4e4b\u524d\u7684\u57fa\u7840\u4e0a\u67091\/3\u7684\u6982\u7387\u88ab\u5206\u5230svr2\u4e0a<\/li>\n
    • \u2026<\/li>\n
    • svr\u589e\u52a0\u5230n\u53f0\u540e\uff0c\u6bcf\u4e00\u4e2auserid\u5728\u4e4b\u524d\u7684\u57fa\u7840\u4e0a\u67091\/n\u7684\u6982\u7387\u88ab\u5206\u5230svr(n-1)\u4e0a<\/li>\n<\/ul>\n
      \u6700\u540e\u4e3a\u4e86\u4fdd\u8bc1\u6bcf\u6b21\u968f\u673a\u7ed3\u679c\u4e00\u6837\uff0c\u6211\u4eec\u9700\u8981\u4f7f\u7528userid\u4f5c\u4e3a\u968f\u673a\u79cd\u5b50<\/p>\n
      int GetSvrIDByUserID(int iUserID, int iSvrNum)\n{\n    if (iSvrNum == 0)\n    {\n        return 0;\n    }\n    srand(iUserID);\/\/\u8bbe\u7f6e\u968f\u673a\u79cd\u5b50\n    int iSvrID = 0;\n    \/\/\u6a21\u62df\u4e00\u4e2a\u4e0d\u65ad\u6269\u5bb9\u7684\u8fc7\u7a0b\n    for (int i = 1; i < iSvrNum; ++i)\n    {\n        double rand_rate = 1.0 \/ (i + 1);\n        double rand_result = ((double)rand()) \/ RAND_MAX;\n        \/\/\u6bcf\u4e00\u8f6e\u67091 \/ (i + 1)\u7684\u6982\u7387\u88ab\u5206\u914d\u5230\u65b0\u7684\u8282\u70b9\n        if (rand_result < rand_rate)\n        {\n            iSvrID = i;\n        }\n    }\n    return iSvrID;\n}<\/code><\/pre>\n
      \u4f7f\u7528\u539f\u5219<\/h4>\n
      \u6211\u4eec\u9700\u8981\u53bb\u4eff\u7167\u865a\u62df\u8282\u70b9\u7684\u65b9\u5f0f\uff0c\u5efa\u7acb\u8d77\u4e00\u79cdsvrid\u5230\u771f\u5b9e\u670d\u52a1\u5668\u7684\u6620\u5c04(\u4f8b\u5982IP)<\/p>\n
      \u6269\u5bb9\u65f6\uff0csvrid\u5fc5\u987b\u4ece0\u5f00\u59cb\uff0c\u6309\u987a\u5e8f\u589e\u5927\uff0c\u4e0d\u80fd\u50cf\u4e00\u81f4\u6027\u54c8\u5e0c\u90a3\u6837\u53ef\u4ee5\u4e0d\u6309\u987a\u5e8f\u65b0\u589e<\/p>\n\n\n\n\n\n\n\n\n
      \u670d\u52a1\u5668\u771f\u5b9eIP<\/td>\n\u6269\u5bb9\u524dSvrID<\/td>\n\u6269\u5bb9\u540eSvrID<\/td>\n<\/tr>\n
      192.168.0.1<\/td>\n0(\u5fc5\u987b\u4ece0\u5f00\u59cb)<\/td>\n0<\/td>\n<\/tr>\n
      192.168.1.1<\/td>\n1<\/td>\n1<\/td>\n<\/tr>\n
      192.168.0.2<\/td>\n2<\/td>\n2<\/td>\n<\/tr>\n
      192.168.1.2<\/td>\n3<\/td>\n3<\/td>\n<\/tr>\n
      192.168.0.5(\u65b0\u589e)<\/span><\/td>\n<\/td>\n4\uff08\u53ea\u80fd\u9012\u589e\uff09<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
      \u7f29\u5bb9\u65f6\uff0c\u88ab\u79fb\u9664\u7684\u670d\u52a1\u5668\u540e\u9762\u6240\u6709\u670d\u52a1\u5668\u7684svrid\u90fd\u8981 – 1<\/p>\n\n\n\n\n\n\n\n\n
      \u670d\u52a1\u5668\u771f\u5b9eIP<\/td>\n\u7f29\u5bb9\u524dSvrID<\/td>\n\u7f29\u5bb9\u540eSvrID<\/td>\n<\/tr>\n
      192.168.0.1<\/td>\n0(\u5fc5\u987b\u4ece0\u5f00\u59cb)<\/td>\n0<\/td>\n<\/tr>\n
      192.168.1.1<\/td>\n1<\/td>\n1<\/td>\n<\/tr>\n
      192.168.0.2(\u79fb\u9664)<\/span><\/td>\n2<\/td>\n<\/td>\n<\/tr>\n
      192.168.1.2<\/td>\n3<\/td>\n2<\/span><\/td>\n<\/tr>\n
      192.168.0.5<\/td>\n4<\/td>\n3<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
      \u8fd9\u79cd\u72b6\u6001\u4e0b\uff0c\u6bd4\u5982\u7528\u6237\u957f\u8fde\u63a5\u4e2d\u7684\u4fe1\u606f\u5c31\u4e0d\u80fd\u5305\u542bsvrid\uff0c\u800c\u53ea\u80fd\u5305\u542bip(\u6216\u8005\u5176\u4ed6\u4e0d\u4f1a\u6539\u53d8\u7684\u53ef\u4f5c\u4e3a\u552f\u4e00\u7d22\u5f15\u7684\u4fe1\u606f)\uff0c\u5426\u5219\u4e5f\u4f1a\u56e0\u4e3asvrID\u7684\u53d8\u5316\u51fa\u73b0\u4e0d\u4e00\u81f4\u95ee\u9898<\/p>\n
      \u6548\u7387\u95ee\u9898\u53ca\u4f18\u5316\u529e\u6cd5<\/h4>\n
      \u867d\u7136\u4e0a\u8ff0\u7b97\u6cd5\u5df2\u7ecf\u53ef\u4ee5\u6ee1\u8db3\u8981\u6c42\uff0c\u4f46\u662f\u968f\u7740SvrNum\u7684\u589e\u5927\uff0c\u8ba1\u7b97SvrID\u7684\u65f6\u95f4\u4f1a\u8d8a\u6765\u8d8a\u957f\uff0c\u6574\u4e2a\u7b97\u6cd5\u7684\u590d\u6742\u5ea6\u4e3aO(SvrNum)\u3002
      \n\u53e6\u6709\u4e00\u70b9\u8981\u6ce8\u610f\uff0c\u968f\u7740SvrNum\u8d8a\u6765\u8d8a\u5927\uff0c\u8282\u70b9\u88ab\u91cd\u65b0\u5206\u914d\u7684\u6982\u7387\u8d8a\u6765\u8d8a\u5c0f\uff0c\u65e0\u6548\u7684\u904d\u5386\u4e5f\u4f1a\u8d8a\u6765\u8d8a\u591a<\/p>\n
      \u6211\u4eec\u5047\u8bbeb\u8868\u793a\u8df3\u53d8\u7684svrid, \u6269\u5bb9\u5230\u8be5svr\u65f6\u53d1\u751f\u4e86\u8df3\u53d8\u3002j\u8868\u793a\u4e0b\u4e00\u4e2a\u8df3\u53d8\u7684svrid\uff0c\u4eceb\u5f00\u59cb\u6301\u7eed\u6269\u5bb9\uff0c\u76f4\u5230j\u624d\u53d1\u751f\u65b0\u7684\u8df3\u53d8
      \n\u5219\u6709i\u2208(b,j)\uff0cP(j >= i) = (b+1) \/ i
      \n\u8fd9\u4e2aP\u662f\u600e\u4e48\u6765\u7684\uff1f\u6309\u7167\u4e0a\u4e00\u8282\u4ee3\u7801\u4e2d\u6301\u7eed\u6a21\u62df\u6269\u5bb9\u7684\u8fc7\u7a0b\u6211\u4eec\u53ef\u4ee5\u77e5\u9053\uff0c\u8282\u70b9\u4e0d\u91cd\u65b0\u5206\u914d\u5230\u7b2ci\u4e2asvr\u7684\u6982\u7387\u4e3a
      \n1 \u2013 (1 \/ (i + 1)) = i \/ i+1
      \n\u90a3\u4e48\u4ece\u7b2cb+1\u4e2asvr\u5230\u7b2ci-1\u4e2asvr\u8fde\u7eed\u4e0d\u91cd\u5206\u914d\u7684\u6982\u7387\u4e3a
      \n(b+1)\/(b+2) * (b+2)\/(b+3)\u2026 * (i-1)\/(i) = (b+1)\/i
      \n\u6b64\u65f6\u6211\u4eec\u53d6[0,1]\u4e0a\u7684\u4e00\u4e2a\u5747\u5300\u968f\u673a\u6570r\uff0c\u4e14\u6ee1\u8db3r<(b+1)\/i
      \n\u663e\u7136\u6709i < (b+1)\/r\uff0c\u53ef\u5f97i\u7684\u4e0a\u754c\u9650\u4e3a(b+1)\/r
      \n\u53c8\u56e0\u4e3aj>=i, \u6240\u4ee5j\u7684\u4e0b\u754c\u9650\u4e3a(b+1)\/r
      \n\u8fd9\u6837\uff0c\u6211\u4eec\u5c31\u627e\u5230\u4e86\u4ece\u67d0\u4e00\u6b21\u91cd\u65b0\u5206\u914dsvrid\u5230\u4e0b\u4e00\u6b21\u91cd\u5206\u914dsvrid\u7684\u8f6c\u6362\u516c\u5f0f\u4e3a:
      \nj = floor((b+1)\/r)
      \n\u4f7f\u7528\u8fd9\u4e2a\u516c\u5f0f\u53ef\u4ee5\u786e\u5b9a\u6bcf\u4e00\u6b21\u5728\u54ea\u4e00\u4e2asvrid\u4e0a\u91cd\u65b0\u5206\u914d\u4e86\uff0c\u5c31\u4e0d\u7528\u4e86\u904d\u5386SvrNum\u6b21\u4e86\u3002
      \n\u6211\u4eec\u5047\u8bbeuser15\u8fd9\u4e2a\u8282\u70b9\u5728\u6a21\u62df\u6269\u5bb9\u8fc7\u7a0b\u4e2d\u4ecesvr0->svr2\uff0c\u6700\u7ec8\u5206\u914d\u7ed9\u4e86svr2<\/p>\n\n\n\n\n\n
      \u904d\u5386\u8f6e\u6b21<\/td>\n0<\/td>\n1<\/td>\n2<\/td>\n3<\/td>\n4<\/td>\n5<\/td>\n<\/tr>\n
      \u8001\u65b9\u6848<\/td>\n0(\u521d\u59cb\u5206\u914d\u72b6\u6001)<\/td>\n1(\u4e0d\u91cd\u65b0\u5206\u914d)<\/td>\n2(\u91cd\u65b0\u5206\u914d)<\/span><\/td>\n3(\u4e0d\u91cd\u65b0\u5206\u914d)<\/td>\n4(\u4e0d\u91cd\u65b0\u5206\u914d)<\/td>\n\u7ed3\u675f<\/span><\/td>\n<\/tr>\n
      \u65b0\u65b9\u6848<\/td>\n0(\u521d\u59cb\u5206\u914d\u72b6\u6001)<\/td>\n\u4e0b\u4e00\u8df3\u662f2(\u91cd\u65b0\u5206\u914d)<\/span><\/td>\n\u7ed3\u675f<\/span><\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
      int GetSvrIDByUserID(int iUserID, int iSvrNum)\n{\n    srand(iUserID);\/\/\u8bbe\u7f6e\u968f\u673a\u79cd\u5b50\n    int b = -1;\n    int j = 0;\n    while (j < iSvrNum)\n    {\n        b = j;\n        double r = ((double)rand()) \/ RAND_MAX;\n        \/\/\u627e\u5230\u4e0b\u4e00\u8df3\n        j = floor((b + 1) \/ r);\n    }\n    return b;\n}<\/code><\/pre>\n
      \u6700\u7ec8\u4ee3\u7801<\/h3>\n
      \u5b9e\u9645\u8bba\u6587\u4e2d\u505a\u4e86\u8fdb\u4e00\u6b65\u4f18\u5316\uff0c\u4f7f\u7528\u4e86\u7ebf\u6027\u540c\u4f59\u53d1\u751f\u5668\uff0c\u4ee3\u7801\u6700\u7ec8\u5982\u4e0b<\/p>\n
      int32_t JumpConsistentHash(uint64_t key, int32_t num_buckets) {\n    int64_t b = -1, j = 0;\n    while (j < num_buckets) {\n        b = j;\n        key = key * 2862933555777941757ULL + 1;\n        j = (b + 1) * (double(1LL << 31) \/ double((key >> 33) + 1));\n    }\n    return b;\n}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
      4,662 Views\u5728\u4f7f\u7528\u4e00\u81f4\u6027\u54c8\u5e0c\u7b97\u6cd5\u4e4b\u524d\uff0c\u9996\u5148\u6211\u4eec\u8981\u660e\u786e\u8fd9\u4e2a\u7b97\u6cd5\u5230\u5e95\u662f\u7528\u6765\u505a\u4ec0\u4e48\u7684\uff0c\u4e3a\u4ec0\u4e48\u8981\u4f7f\u7528\u4e00\u81f4\u6027\u54c8 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[100],"tags":[],"class_list":["post-1065","post","type-post","status-publish","format-standard","hentry","category-100"],"_links":{"self":[{"href":"http:\/\/www.mrtblog.cn\/index.php?rest_route=\/wp\/v2\/posts\/1065","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.mrtblog.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.mrtblog.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.mrtblog.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.mrtblog.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1065"}],"version-history":[{"count":14,"href":"http:\/\/www.mrtblog.cn\/index.php?rest_route=\/wp\/v2\/posts\/1065\/revisions"}],"predecessor-version":[{"id":1284,"href":"http:\/\/www.mrtblog.cn\/index.php?rest_route=\/wp\/v2\/posts\/1065\/revisions\/1284"}],"wp:attachment":[{"href":"http:\/\/www.mrtblog.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1065"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.mrtblog.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1065"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.mrtblog.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1065"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}