{"id":50165,"date":"2023-07-14T22:36:49","date_gmt":"2023-09-16T02:24:36","guid":{"rendered":"https:\/\/www.silicloud.com\/zh\/blog\/%e3%80%90%e9%80%9a%e5%90%91cassandra%e6%97%a5%e3%80%91cassandra%e5%8f%8d%e5%ba%94%e5%bc%8f%e7%bc%96%e7%a8%8b%e9%a3%8e%e6%a0%bc%e4%bb%8b%e7%bb%8d%e5%92%8c%e5%9f%ba%e6%9c%ac%e4%bd%bf%e7%94%a8%e6%96%b9\/"},"modified":"2024-04-30T13:35:42","modified_gmt":"2024-04-30T05:35:42","slug":"%e3%80%90%e9%80%9a%e5%90%91cassandra%e6%97%a5%e3%80%91cassandra%e5%8f%8d%e5%ba%94%e5%bc%8f%e7%bc%96%e7%a8%8b%e9%a3%8e%e6%a0%bc%e4%bb%8b%e7%bb%8d%e5%92%8c%e5%9f%ba%e6%9c%ac%e4%bd%bf%e7%94%a8%e6%96%b9","status":"publish","type":"post","link":"https:\/\/www.silicloud.com\/zh\/blog\/%e3%80%90%e9%80%9a%e5%90%91cassandra%e6%97%a5%e3%80%91cassandra%e5%8f%8d%e5%ba%94%e5%bc%8f%e7%bc%96%e7%a8%8b%e9%a3%8e%e6%a0%bc%e4%bb%8b%e7%bb%8d%e5%92%8c%e5%9f%ba%e6%9c%ac%e4%bd%bf%e7%94%a8%e6%96%b9\/","title":{"rendered":"\u3010\u901a\u5411Cassandra\u65e5\u3011Cassandra\u53cd\u5e94\u5f0f\u7f16\u7a0b\u98ce\u683c~\u4ecb\u7ecd\u548c\u57fa\u672c\u4f7f\u7528\u65b9\u6cd5"},"content":{"rendered":"

\u9996\u5148<\/h1>\n

Cassandra\u5728\u4e1c\u4eac\u7684\u65e5\u5b50<\/h2>\n

\u4eca\u5e74\uff0c2023\u5e746\u67081\u65e5\uff0cCassandra Day\u5c06\u5728\u65e5\u672c\u4e3e\u529e\u3002Cassandra Day\u53bb\u5e74\u5728\u67cf\u6797\u3001\u4f26\u6566\u3001\u963f\u59c6\u65af\u7279\u4e39\u3001\u6cb3\u5185\u3001\u96c5\u52a0\u8fbe\u3001\u4f11\u65af\u987f\u3001\u5723\u514b\u62c9\u62c9\u3001\u897f\u96c5\u56fe\u3001\u65b0\u52a0\u5761\u4e5f\u4e3e\u529e\u4e86\u3002<\/p>\n

\u70ba\u4e86\u672c\u6b21\u5728\u6771\u4eac\u8209\u8fa6\u7684\u6d3b\u52d5\uff0c\u6211\u5011\u5c07\u767c\u8868\u6709\u95dcApache Cassandra\u7684\u6587\u7ae0\u3002<\/p>\n

\"image.png\"<\/div>\n

\u5173\u4e8eApache Cassandra<\/h2>\n

\u5982\u679c\u7528\u4e00\u53e5\u8bdd\u6765\u6982\u62ec\uff0cApache Cassandra\u5c31\u662f\u4e00\u4e2a\u5f00\u6e90\u7684\u5206\u5e03\u5f0f\u6570\u636e\u5e93\u7ba1\u7406\u7cfb\u7edf\u3002<\/p>\n

\u4e0e\u5176\u4ed6\u5206\u5e03\u5f0f\u6570\u636e\u5e93\u7ba1\u7406\u7cfb\u7edf\u4e00\u6837\uff0c\u53ef\u4ee5\u4f7f\u7528\u591a\u4e2a\u901a\u7528\u670d\u52a1\u5668\u6765\u6784\u5efa\u4e00\u4e2a\u6570\u636e\u5e93\uff08\u4e5f\u53ef\u4ee5\u53ea\u4f7f\u7528\u4e00\u4e2a\u670d\u52a1\u5668\u8fdb\u884c\u5f00\u53d1\u7b49\u76ee\u7684\uff09\u3002<\/p>\n

\u5728\u8fd9\u91cc\uff0c\u5c06\u8be6\u7ec6\u7684\u8bf4\u660e\u7701\u7565\u6389\uff0c\u6211\u4eec\u5c06\u628a\u91cd\u70b9\u653e\u5728\u5411\u611f\u5174\u8da3\u7684\u4eba\u4ecb\u7ecd\u7684\u89d2\u8272\u4e0a\uff0c\u8fd9\u4e2a\u89d2\u8272\u5df2\u7ecf\u4ea4\u7531\u5b98\u65b9\u7f51\u7ad9\u548c\u7ef4\u57fa\u767e\u79d1\u6765\u627f\u62c5\u3002<\/p>\n

 <\/p>\n

Cassandra\u7684\u53cd\u5e94\u5f0f\u7f16\u7a0b\u65b9\u5f0f~\u4ecb\u7ecd<\/h1>\n

Cassandra\u7684Java\u9a71\u52a8\u7a0b\u5e8f\u63d0\u4f9b\u4e86\u5185\u7f6e\u7684\u54cd\u5e94\u5f0f\u67e5\u8be2\u652f\u6301\u3002<\/p>\n

\u8fd9\u7bc7\u6587\u7ae0\u4f7f\u7528\u4e86\u622a\u81f32023\u5e745\u6708\u6700\u65b0\u7684Java\u9a71\u52a8\u7a0b\u5e8f4.15\u4f5c\u4e3a\u57fa\u7840\u3002<\/p>\n

 <\/p>\n

ReactiveSession\u901a\u8fc7\u6269\u5c55CqlSession\u63a5\u53e3\uff0c\u5e76\u65b0\u589e\u7279\u6b8a\u65b9\u6cd5\u6765\u6267\u884c\u4ee5\u54cd\u5e94\u5f0f\u6d41\u8868\u793a\u7684\u8bf7\u6c42\u3002<\/p>\n

\u54cd\u5e94\u5f0f\u6d41API<\/h2>\n

Java \u9a71\u52a8\u7a0b\u5e8f 4.15 \u7684\u53cd\u5e94\u5f0f\u529f\u80fd\u662f\u57fa\u4e8e Reactive Streams API \u5f00\u53d1\u7684\u3002\uff08\u5728 3.x \u7248\u672c\u4e2d\uff0c\u5b83\u662f\u57fa\u4e8e Google \u7684 Java \u5e93 Guava \u5f00\u53d1\u7684\uff09<\/p>\n

 <\/p>\n

\u5982\u679c\u5e94\u7528\u7a0b\u5e8f\u5b8c\u5168\u4e0d\u4f7f\u7528\u53cd\u5e94\u5f0f\u67e5\u8be2\uff0c\u5219\u53ef\u4ee5\u901a\u8fc7\u6392\u9664\u5b83\u6765\u6700\u5c0f\u5316\u9a71\u52a8\u7a0b\u5e8f\u5728\u8fd0\u884c\u65f6\u7684\u4f9d\u8d56\u5173\u7cfb\u6570\u91cf\u3002<\/p>\n

\u7531\u4e8e\u5386\u53f2\u539f\u56e0\uff0c\u4e0e\u53cd\u5e94\u5f0f\u76f8\u5173\u7684\u9a71\u52a8\u7a0b\u5e8f\u7c7b\u578b\u5b58\u5728\u4e8e\u4ee5DSE\uff08DataStax Enterprise\u7684\u7f29\u5199\uff09\u4e3a\u9996\u7684\u5305\u4e2d\u3002
\n\u7136\u800c\uff0c\u53cd\u5e94\u5f0f\u67e5\u8be2\u4e5f\u53ef\u4ee5\u5728\u5f00\u6e90\u7684Apache Cassandra\u4e2d\u5de5\u4f5c\u3002<\/p>\n

\u54cd\u5e94\u5f0f\u6267\u884c\u6a21\u578b\u91c7\u7528\u4e86\u975e\u963b\u585e\u65b9\u5f0f\u5b9e\u73b0\u3002\u6709\u5173\u8be6\u7ec6\u4fe1\u606f\uff0c\u8bf7\u53c2\u9605\u975e\u963b\u585e\u7f16\u7a0b\u624b\u518c\u3002<\/p>\n

 <\/p>\n

\u7b80\u800c\u8a00\u4e4b<\/h2>\n

ReactiveSession\u516c\u5f00\u4e86\u4e24\u4e2a\u516c\u5171\u65b9\u6cd5\u3002<\/p>\n

ReactiveResultSet executeReactive(String query);<\/p>\n

ReactiveResultSet executeReactive(Statement<?> statement);<\/p>\n

\u65e0\u8bba\u54ea\u79cd\u65b9\u6cd5\uff0c\u90fd\u4f1a\u8fd4\u56de\u4e00\u4e2a\u901a\u5e38\u7684ResultSet\u7684\u54cd\u5e94\u5f0f\u6d41\u7248\u672c\uff0c\u5373ReactiveResultSet\u3002
\n\u5728\u54cd\u5e94\u5f0f\u7f16\u7a0b\u7684\u4e0a\u4e0b\u6587\u4e2d\uff0cReactiveResultSet\u8d77\u5230\u5904\u7406\u67e5\u8be2\u7ed3\u679c\u7684”\u53d1\u5e03\u8005”\u7684\u89d2\u8272\u3002<\/p>\n

\u5f53\u8ba2\u9605 ReactiveResultSet \u65f6\uff0c\u9700\u8981\u6ce8\u610f\u4ee5\u4e0b\u4e24\u70b9\u3002<\/p>\n

ReactiveResultSet\u30c9\u30e9\u30a4\u30d0\u30fc\u306b\u3088\u3063\u3066\u8fd4\u3055\u308c\u308b\u3059\u3079\u3066\u306e\u5b9f\u88c5\u306f\u3001\u30c7\u30d5\u30a9\u30eb\u30c8\u3067\u306f\u3001\u30b3\u30fc\u30eb\u30c9\u3001\u30e6\u30cb\u30ad\u30e3\u30b9\u30c8\u3001\u5358\u4e00\u30b5\u30d6\u30b9\u30af\u30ea\u30d7\u30b7\u30e7\u30f3\u306e\u307f\u306e\u30d1\u30d6\u30ea\u30c3\u30b7\u30e3\u30fc\u3067\u3059\u3002\u3064\u307e\u308a\u3001\u8907\u6570\u306e\u30b5\u30d6\u30b9\u30af\u30e9\u30a4\u30d0\u30fc\u306e\u5229\u7528\u306f\u30b5\u30dd\u30fc\u30c8\u3055\u308c\u3066\u3044\u307e\u305b\u3093\u3002\u8907\u6570\u306e\u30c0\u30a6\u30f3\u30b9\u30c8\u30ea\u30fc\u30e0 \u30b5\u30d6\u30b9\u30af\u30e9\u30a4\u30d0\u30fc\u3067\u305d\u308c\u3089\u3092\u4f7f\u7528\u3059\u308b\u5fc5\u8981\u304c\u3042\u308b\u5834\u5408\u306f\u3001\u305d\u306e\u3088\u3046\u306a\u30d1\u30d6\u30ea\u30c3\u30b7\u30e3\u30fc\u306b\u3088\u3063\u3066\u751f\u6210\u3055\u308c\u305f\u7d50\u679c\u3092\u30ad\u30e3\u30c3\u30b7\u30e5\u3059\u308b\u3053\u3068\u3092\u691c\u8a0e\u3057\u307e\u3059\u3002\uff08\u30c9\u30ad\u30e5\u30e1\u30f3\u30c8\u3067\u306f\u3001\u30ad\u30e3\u30c3\u30b7\u30f3\u30b0\u306e\u4f8b\u304c\u7d39\u4ecb\u3055\u308c\u3066\u3044\u307e\u3059\uff09\u3002<\/p>\n

ReactiveResultSet\u306f\u3001\u5185\u90e8\u7684\u306b\u3001IO \u30b9\u30ec\u30c3\u30c9\u3092\u7528\u3044\u307e\u3059\u3002\u30b5\u30d6\u30b9\u30af\u30e9\u30a4\u30d0\u30fc\u306e\u5b9f\u88c5\u8005\u306f\u3001 Reactive Streams \u4ed5\u69d8\u30eb\u30fc\u30eb 2.2\u3092\u9806\u5b88\u3057\u3001\u8ca0\u8377\u306e\u9ad8\u3044\u8a08\u7b97\u3092\u5b9f\u884c\u3057\u305f\u308a\u3001onNext\u547c\u3073\u51fa\u3057\u5185\u3067\u547c\u3073\u51fa\u3057\u3092\u30d6\u30ed\u30c3\u30af\u3057\u305f\u308a\u3057\u306a\u3044\u3088\u3046\u306b\u3059\u308b\u3053\u3068\u304c\u63a8\u5968\u3055\u308c\u307e\u3059\u3002\u3053\u308c\u3089\u3092\u5b9f\u884c\u3059\u308b\u3068\u3001\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306b\u5f71\u97ff\u3092\u4e0e\u3048\u308b\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002\u30b5\u30d6\u30b9\u30af\u30e9\u30a4\u30d0\u30fc\u3067\u306f\u3001\u30c7\u30fc\u30bf\u3092\u51e6\u7406\u30ed\u30b8\u30c3\u30af\u306b\u975e\u540c\u671f\u7684\u306b\u30c7\u30a3\u30b9\u30d1\u30c3\u30c1\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u57fa\u7840\u7528\u6cd5<\/h2>\n

\u54cd\u5e94\u5f0f\u9605\u8bfb\u98ce\u683c<\/h3>\n

\u4ee5\u4e0b\u662f\u4e00\u4e2a\u793a\u4f8b\uff0c\u5b83\u4ece\u8868\u4e2d\u8bfb\u53d6\u5e76\u5c06\u8fd4\u56de\u7684\u6240\u6709\u884c\u8f93\u51fa\u5230\u63a7\u5236\u53f0\u3002<\/p>\n

try<\/span> (<\/span>CqlSession<\/span> session<\/span> =<\/span> ...)<\/span> {<\/span>\r\n      Flux<\/span>.<\/span>from<\/span>(<\/span>session<\/span>.<\/span>executeReactive<\/span>(<\/span>\"SELECT ...\"<\/span>))<\/span>\r\n          .<\/span>doOnNext<\/span>(<\/span>System<\/span>.<\/span>out<\/span>::<\/span>println<\/span>)<\/span>\r\n          .<\/span>blockLast<\/span>();<\/span>\r\n}<\/span> catch<\/span> (<\/span>DriverException<\/span> e<\/span>)<\/span> {<\/span>\r\n  e<\/span>.<\/span>printStackTrace<\/span>();<\/span>\r\n}<\/span>\r\n<\/code><\/pre>\n
\u5199\u4f5c\u7684\u54cd\u5e94\u5f0f\u98ce\u683c<\/h3>\n
\u5728\u628a\u67e5\u8be2\u7ed3\u679c\u8f93\u51fa\u5230\u63a7\u5236\u53f0\u540e\uff0c\u5c06\u884c\u63d2\u5165\u5230\u8868\u4e2d\u3002<\/p>\n
try<\/span> (<\/span>CqlSession<\/span> session<\/span> =<\/span> ...)<\/span> {<\/span>\r\n  Flux<\/span>.<\/span>just<\/span>(<\/span>\"INSERT ...\"<\/span>,<\/span> \"INSERT ...\"<\/span>,<\/span> \"INSERT ...\"<\/span>,<\/span> ...)<\/span>\r\n      .<\/span>doOnNext<\/span>(<\/span>System<\/span>.<\/span>out<\/span>::<\/span>println<\/span>)<\/span>\r\n      .<\/span>flatMap<\/span>(<\/span>session:<\/span>:<\/span>executeReactive<\/span>)<\/span>\r\n      .<\/span>blockLast<\/span>();<\/span>\r\n}<\/span> catch<\/span> (<\/span>DriverException<\/span> e<\/span>)<\/span> {<\/span>\r\n  e<\/span>.<\/span>printStackTrace<\/span>();<\/span>\r\n}<\/span>\r\n<\/code><\/pre>\n
\u8bf7\u6ce8\u610f\uff0c\u53ea\u6709\u5728\u8bed\u53e5\u4ee5\u54cd\u5e94\u65b9\u5f0f\u6267\u884c\u65f6\uff0c\u5b9e\u9645\u8bf7\u6c42\u624d\u4f1a\u5728 ReactiveResultSet \u88ab\u8ba2\u9605\u65f6\u89e6\u53d1\u3002\u6362\u53e5\u8bdd\u8bf4\uff0c\u5f53 executeReactive \u65b9\u6cd5\u8fd4\u56de\u65f6\uff0c\u8fd8\u6ca1\u6709\u6267\u884c\u4efb\u4f55\u64cd\u4f5c\u3002\u8fd9\u5c31\u662f\u4e3a\u4ec0\u4e48\u5728\u4e0a\u8ff0\u5199\u5165\u793a\u4f8b\u4e2d\u4f7f\u7528 flatMap \u7684\u539f\u56e0\u3002\u8be5\u65b9\u6cd5\u5c06\u5904\u7406\u7531 executeReactive \u65b9\u6cd5\u8c03\u7528\u8fd4\u56de\u7684\u6bcf\u4e2a\u8ba2\u9605\u3002\u4f8b\u5982\uff0c\u5728\u4ee5\u4e0b\u4ee3\u7801\u4e2d\uff0c\u7531\u4e8e ReactiveResultSetsession.executeReactiveReactiveResultSet \u5c1a\u672a\u88ab\u8ba2\u9605\uff0c\u56e0\u6b64\u67e5\u8be2\u4e0d\u4f1a\u88ab\u6267\u884c\u3002<\/p>\n
\/\/ DON'T DO THIS<\/span>\r\nFlux<\/span>.<\/span>just<\/span>(<\/span>\"INSERT INTO ...\"<\/span>)<\/span>\r\n     \/\/ The returned ReactiveResultSet is not subscribed to<\/span>\r\n    .<\/span>doOnNext<\/span>(<\/span>session:<\/span>:<\/span>executeReactive<\/span>)<\/span>\r\n    .<\/span>blockLast<\/span>();<\/span>\r\n<\/code><\/pre>\n
\u8bbf\u95ee\u67e5\u8be2\u5143\u6570\u636e<\/h2>\n
ReactiveResultSet\u516c\u5f00\u4e86\u4e0e\u8bf7\u6c42\u6267\u884c\u548c\u67e5\u8be2\u5143\u6570\u636e\u76f8\u5173\u7684\u6709\u7528\u4fe1\u606f\u3002<\/p>\n
    \n
  • \n
      Publisher<? extends ColumnDefinitions> getColumnDefinitions();<\/ul>\n<\/li>\n<\/ul>\n
       <\/p>\n
        \n
      • \n
          Publisher<? extends ExecutionInfo> getExecutionInfos();<\/ul>\n<\/li>\n<\/ul>\n
           <\/p>\n
            Publisher wasApplied();<\/ul>\n
            \u53ea\u9700\u8ba2\u9605\u5373\u53ef\u68c0\u7d22\u4e0a\u8ff0\u53d1\u5e03\u8005\u7684\u5185\u5bb9\u3002\u8bf7\u6ce8\u610f\uff0c\u5728\u67e5\u8be2\u5b8c\u6210\u4e4b\u524d\uff0c\u8fd9\u4e9b\u53d1\u5e03\u8005\u662f\u65e0\u6cd5\u6267\u884c\u7684\u3002\u5982\u679c\u67e5\u8be2\u5931\u8d25\uff0c\u8fd9\u4e9b\u53d1\u5e03\u8005\u5c06\u4ee5\u540c\u6837\u7684\u9519\u8bef\u5931\u8d25\u3002<\/p>\n
            \u5728\u4e0b\u9762\u7684\u793a\u4f8b\u4e2d\uff0c\u6267\u884c\u67e5\u8be2\u5e76\u5c06\u6240\u6709\u53ef\u7528\u7684\u5143\u6570\u636e\u8f93\u51fa\u5230\u63a7\u5236\u53f0\u3002<\/p>\n
            ReactiveResultSet<\/span> rs<\/span> =<\/span> session<\/span>.<\/span>executeReactive<\/span>(<\/span>\"SELECT ...\"<\/span>);<\/span>\r\n\/\/ execute the query first<\/span>\r\nFlux<\/span>.<\/span>from<\/span>(<\/span>rs<\/span>).<\/span>blockLast<\/span>();<\/span>\r\n\/\/ then retrieve query metadata<\/span>\r\nSystem<\/span>.<\/span>out<\/span>.<\/span>println<\/span>(<\/span>\"Column definitions: \"<\/span>);<\/span>\r\nMono<\/span>.<\/span>from<\/span>(<\/span>rs<\/span>.<\/span>getColumnDefinitions<\/span>()).<\/span>doOnNext<\/span>(<\/span>System<\/span>.<\/span>out<\/span>::<\/span>println<\/span>).<\/span>block<\/span>();<\/span>\r\nSystem<\/span>.<\/span>out<\/span>.<\/span>println<\/span>(<\/span>\"Execution infos: \"<\/span>);<\/span>\r\nFlux<\/span>.<\/span>from<\/span>(<\/span>rs<\/span>.<\/span>getExecutionInfos<\/span>()).<\/span>doOnNext<\/span>(<\/span>System<\/span>.<\/span>out<\/span>::<\/span>println<\/span>).<\/span>blockLast<\/span>();<\/span>\r\nSystem<\/span>.<\/span>out<\/span>.<\/span>println<\/span>(<\/span>\"Was applied: \"<\/span>);<\/span>\r\nMono<\/span>.<\/span>from<\/span>(<\/span>rs<\/span>.<\/span>wasApplied<\/span>()).<\/span>doOnNext<\/span>(<\/span>System<\/span>.<\/span>out<\/span>::<\/span>println<\/span>).<\/span>block<\/span>();<\/span>\r\n<\/code><\/pre>\n
            \u60a8\u4e5f\u53ef\u4ee5\u5728\u884c\u7ea7\u522b\u68c0\u67e5\u67e5\u8be2\u5143\u6570\u636e\u3002\u7531\u54cd\u5e94\u5f0f\u67e5\u8be2\u6267\u884c\u8fd4\u56de\u7684\u6bcf\u4e00\u884c\u90fd\u662fReactiveRow\u7c7b\u7684\u54cd\u5e94\u5f0f\u5b9e\u73b0\u3002<\/p>\n
            \u5728ReactiveRow\u4e2d\uff0c\u5c06\u516c\u5f00\u4e0eReactiveResultSet\u76f8\u540c\u7c7b\u578b\u7684\u67e5\u8be2\u5143\u6570\u636e\u548c\u6267\u884c\u4fe1\u606f\uff0c\u4f46\u662f\u5bf9\u4e8e\u6bcf\u4e00\u884c\u6765\u8bf4\u4f1a\u6709\u4ee5\u4e0b\u4e0d\u540c\u3002<\/p>\n
              \n
            • \n
                ColumnDefinitions getColumnDefinitions();<\/ul>\n<\/li>\n<\/ul>\n
                 <\/p>\n
                  \n
                • \n
                    ExecutionInfo getExecutionInfo();<\/ul>\n<\/li>\n<\/ul>\n
                     <\/p>\n
                      boolean wasApplied();<\/ul>\n
                      \u5728\u4e0b\u9762\u7684\u4f8b\u5b50\u4e2d\uff0c\u6211\u4eec\u5c06\u6267\u884c\u67e5\u8be2\u5e76\u9488\u5bf9\u8fd4\u56de\u7684\u6bcf\u4e00\u884c\u8f93\u51fa\u5904\u7406\u8be5\u884c\u7684\u534f\u8c03\u5668\u3002\u7136\u540e\uff0c\u6211\u4eec\u5c06\u83b7\u53d6\u8fde\u63a5\u5230\u6ee1\u8db3\u67e5\u8be2\u6761\u4ef6\u7684\u6240\u6709\u534f\u8c03\u5668\uff0c\u5e76\u5c06\u5b83\u4eec\u8f93\u51fa\u5230\u63a7\u5236\u53f0\u4e0a\u3002<\/p>\n
                      Iterable<\/span><<\/span>Node<\/span>><\/span> coordinators<\/span> =<\/span> Flux<\/span>.<\/span>from<\/span>(<\/span>session<\/span>.<\/span>executeReactive<\/span>(<\/span>\"SELECT ...\"<\/span>))<\/span>\r\n    .<\/span>doOnNext<\/span>(<\/span>\r\n        row<\/span> -><\/span>\r\n            System<\/span>.<\/span>out<\/span>.<\/span>printf<\/span>(<\/span>\r\n                \"Row %s was obtained from coordinator %s%n\"<\/span>,<\/span>\r\n                row<\/span>,<\/span>\r\n                row<\/span>.<\/span>getExecutionInfo<\/span>().<\/span>getCoordinator<\/span>()))<\/span>\r\n    .<\/span>map<\/span>(<\/span>ReactiveRow:<\/span>:<\/span>getExecutionInfo<\/span>)<\/span>\r\n    \/\/ dedup by coordinator (note: this is dangerous on a large result set)<\/span>\r\n    .<\/span>groupBy<\/span>(<\/span>ExecutionInfo:<\/span>:<\/span>getCoordinator<\/span>)<\/span>\r\n    .<\/span>map<\/span>(<\/span>GroupedFlux:<\/span>:<\/span>key<\/span>)<\/span>\r\n    .<\/span>toIterable<\/span>();<\/span>\r\nSystem<\/span>.<\/span>out<\/span>.<\/span>println<\/span>(<\/span>\"Contacted coordinators: \"<\/span> +<\/span> coordinators<\/span>);<\/span>\r\n<\/code><\/pre>\n
                      \u6700\u540e<\/h2>\n
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                      \u6211\u5e0c\u671b\u5728\u53e6\u4e00\u4e2a\u673a\u4f1a\u4e0a\u4ecb\u7ecd\u66f4\u6df1\u5165\u7684\u5185\u5bb9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
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