春天·卡夫卡听着regex

问题描述

我正在尝试使用以下代码收听新创建的主题，但不起作用。您能告诉我下面的代码是否正确吗？

public class KafkaMessageListener {
    private static final Logger LOGGER = LoggerFactory.getLogger(KafkaMessageListener.class);

    private final ProcessEventModel eventModel;

    @KafkaListener(topicPattern = "betsyncDataTopic*")
    public void receive(ConsumerRecord<String, String> consumerRecord) {
        LOGGER.info("received payload at '{}'", consumerRecord.timestamp());
        eventModel.process(consumerRecord.value());
    }

推荐答案

您的正则表达式无效；它应该是betsyncDataTopic.*。

@KafkaListener(id = "xxx", topicPattern = "kbgh.*")
public void listen(String in) {
    System.out.println(in);
}

...

partitions assigned: [kbgh290-0]

编辑

如果稍后添加与模式匹配的新主题，则在重新平衡之前会有延迟。根据KafkaConsumerjavadoc...

 * Subscribe to all topics matching specified pattern to get dynamically assigned partitions.
 * The pattern matching will be done periodically against topic existing at the time of check.
 * <p>
 * As part of group management, the consumer will keep track of the list of consumers that
 * belong to a particular group and will trigger a rebalance operation if one of the
 * following events trigger -
 * <ul>
 * <li>Number of partitions change for any of the subscribed list of topics
 * <li>Topic is created or deleted
 * <li>An existing member of the consumer group dies
 * <li>A new member is added to an existing consumer group via the join API
 * </ul>

我刚刚运行了一个测试；在12:13:32处添加了一个新的匹配主题；结果：

2018-02-12 12:17:30.394  INFO 88028 --- [      xxx-0-C-1] o.s.k.l.KafkaMessageListenerContainer    
: partitions revoked: [kbgh290-0]
2018-02-12 12:17:30.450  INFO 88028 --- [      xxx-0-C-1] o.s.k.l.KafkaMessageListenerContainer    
: partitions assigned: [kbgh290-0, kbghNew-0]

所以需要几分钟。

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