Question

我正在两个简单的KTable之间进行连接，假设我有2个主题，包含以下数据，请参阅详细信息：

第一个主题

1 | Victor C.

1 |瓦迪姆C.

2 | Vasile P.

3 | Vitalie C.

4 | Oleg C。

第二个主题

1 |程序员

2 |管理员

3 |管理器

当我执行以下查询时，SQL行为显然很明显，并且输出对我来说是明白的：

SELECT * FROM firstTable
INNER JOIN secondTable
ON firstTable.ID = secondTable.ID

1 | Victor C. | 1 |程序员

1 |瓦迪姆C. | 1 |程序员

2 | Vasile P. | 2 |管理员

3 | Vitalie C. | 3 |管理器

所以，我正在玩Kafka，我尝试做同样的行为，但加入的流的结果完全混淆了我的想法

请参阅代码段详细信息：

  @Test
  public void joinKTableToKTableWhereKeyValueIsIntegerAndString() throws Exception {
      InternalTestConfiguration itc = getInternalTestConfiguration();
      List < String > topics = Arrays.asList(itc.getFirstTopic(), itc.getSecondTopic(), itc.getProjectionTopic(), itc.getFirstKeyedTopic(), itc.getSecondKeyedTopic());
      KafkaStreams streams = null;

      try {
          Integer partitions = 1;
          Integer replication = 1;
          RestUtils.createTopics(topics, partitions, replication, new Properties());

          List < KeyValue < Integer, String >> employees = Arrays.asList(
              new KeyValue < > (1, "Victor C."),
              new KeyValue < > (1, "Vadim C."),
              new KeyValue < > (2, "Vasile P."),
              new KeyValue < > (3, "Vitalie C."),
              new KeyValue < > (4, "Oleg C.")
          );

          List < KeyValue < Integer, String >> specialities = Arrays.asList(
              new KeyValue < > (1, "Programmer"),
              new KeyValue < > (2, "Administrator"),
              new KeyValue < > (3, "Manager")
          );

          List < KeyValue < Integer, String >> expectedResults = Arrays.asList(
              new KeyValue < > (1, "Victor C./Programmer"),
              new KeyValue < > (1, "Vadim C./Programmer"),
              new KeyValue < > (2, "Vasile P./Administrator"),
              new KeyValue < > (3, "Vitalie C../Manager")
          );

          final Serde < Integer > keySerde = Serdes.Integer();
          final Serde < String > valueSerde = Serdes.String();

          Properties streamsConfiguration = new Properties();
          streamsConfiguration.put(StreamsConfig.APPLICATION_ID_CONFIG, itc.getAppIdConfig());
          streamsConfiguration.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, BOOTSTRAP_SERVERS_CONFIG);
          streamsConfiguration.put(StreamsConfig.ZOOKEEPER_CONNECT_CONFIG, ZOOKEEPER_CONNECT_CONFIG);
          streamsConfiguration.put(StreamsConfig.KEY_SERDE_CLASS_CONFIG, Serdes.Integer().getClass().getName());
          streamsConfiguration.put(StreamsConfig.VALUE_SERDE_CLASS_CONFIG, Serdes.String().getClass().getName());
          streamsConfiguration.put(StreamsConfig.COMMIT_INTERVAL_MS_CONFIG, 10 * 1000);
          //streamsConfiguration.put(StreamsConfig.CACHE_MAX_BYTES_BUFFERING_CONFIG, 0);
          streamsConfiguration.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
          streamsConfiguration.put(StreamsConfig.STATE_DIR_CONFIG, TestUtils.tempDirectory().getAbsolutePath());

          KStreamBuilder builder = new KStreamBuilder();

          KTable < Integer, String > firstKTable = builder.table(keySerde, valueSerde, itc.getFirstTopic(), itc.getFirstStore());
          KTable < Integer, String > secondKTable = builder.table(keySerde, valueSerde, itc.getSecondTopic(), itc.getSecondStore());
          KTable < Integer, String > projectionKTable = firstKTable.join(secondKTable, (l, r) - > {
              return l + "/" + r;
          });

          projectionKTable.to(keySerde, valueSerde, itc.getProjectionTopic());

          streams = new KafkaStreams(builder, streamsConfiguration);

          streams.start();

          Properties cfg1 = new Properties();
          cfg1.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, BOOTSTRAP_SERVERS_CONFIG);
          cfg1.put(ProducerConfig.ACKS_CONFIG, "all");
          cfg1.put(ProducerConfig.RETRIES_CONFIG, 0);
          cfg1.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, IntegerSerializer.class);
          cfg1.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
          IntegrationTestUtils.produceKeyValuesSynchronously(itc.getFirstTopic(), employees, cfg1);

          Properties cfg2 = new Properties();
          cfg2.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, BOOTSTRAP_SERVERS_CONFIG);
          cfg2.put(ProducerConfig.ACKS_CONFIG, "all");
          cfg2.put(ProducerConfig.RETRIES_CONFIG, 0);
          cfg2.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, IntegerSerializer.class);
          cfg2.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
          IntegrationTestUtils.produceKeyValuesSynchronously(itc.getSecondTopic(), specialities, cfg2);

          Properties consumerConfig = new Properties();
          consumerConfig.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, BOOTSTRAP_SERVERS_CONFIG);
          consumerConfig.put(ConsumerConfig.GROUP_ID_CONFIG, itc.getGroupIdConfig());
          consumerConfig.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
          consumerConfig.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, IntegerDeserializer.class);
          consumerConfig.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);

          List < KeyValue < Integer, String >> actualResults = IntegrationTestUtils.waitUntilMinKeyValueRecordsReceived(consumerConfig, itc.getProjectionTopic(), expectedResults.size());

          assertThat(actualResults).containsExactlyElementsOf(expectedResults);               
      } finally {
          if (streams != null) {
              streams.close();
          }

          RestUtils.deleteTopics(topics);
      }
  }

我希望得到与SQL相同的结果，但事实并非如此。

//streamsConfiguration.put(StreamsConfig.CACHE_MAX_BYTES_BUFFERING_CONFIG，0）＆＃34;的结果停用

1，Vadim C./Programmer

2，Vasile P./Administrator

3，Vitalie C./Manager

1，Vadim C./Programmer

2，Vasile P./Administrator

3，Vitalie C./Manager

使用streamsConfiguration.put（StreamsConfig.CACHE_MAX_BYTES_BUFFERING_CONFIG，0）的结果;启用

1，Vadim C./Programmer

2，Vasile P./Administrator

3，Vitalie C./Manager

无论如何这两个结果都与SQL不一样，请帮助我理解这一点，因为我已经杀了我自己:(

Answer 1

在您的SQL比较中，该数字似乎不是主键，因为Victor C.和Vadim C.都与1

Kafka Streams错误地加入了2个简单KTables的结果

1 个答案: