java - 如果主题不存在，Kafka 生产者会挂起

Question

我是 Kafka 的新手，正在尝试实现一个简单的生产者，将数据发送到主题。如果该主题不存在，我想将此问题作为异常处理。

private Producer<UUID, Object> producer = createProducer(); 

private static Producer createProducer() {
    Properties props = new Properties();
    props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG,
            "mybootstrapserveraddress");
    props.put(ProducerConfig.CLIENT_ID_CONFIG, "ADAPTER");
    props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG,
            UUIDSerializer.class);
    props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG,
            JsonSerializer.class);
    props.put(ProducerConfig.REQUEST_TIMEOUT_MS_CONFIG,
            1000);
    props.put(ProducerConfig.RETRIES_CONFIG,
            1);
    props.put(ProducerConfig.RETRY_BACKOFF_MS_CONFIG,
            1000);
    return new KafkaProducer<>(props);
}

public void send(Event event, String topic){
    try {
        UUID key = UUID.randomUUID();
        producer.send(new ProducerRecord<>(topic, key , event), (rm, ex) -> {
            if (ex != null) {
                log.warn("Error sending message with key {}\n{}", new Object[]{key, ex.getMessage()});
            } else {
                log.info( "Partition for key-value {} is {}", new Object[]{key, rm.partition()});
            }
        });
    } catch (Exception e) {
        log.error("Failed to send message ",e);
    } finally {
        producer.flush();
    }
}

但是，如果主题不存在，则继续轮询消息。 ProducerConfig 的超时和重试将被忽略。

[kafka-producer-network-thread | ADAPTER] WARN org.apache.kafka.clients.NetworkClient - [Producer clientId=ADAPTER] Error while fetching metadata with correlation id 6 : {my-example-topic2=UNKNOWN_TOPIC_OR_PARTITION}
[kafka-producer-network-thread | ADAPTER] WARN org.apache.kafka.clients.NetworkClient - [Producer clientId=ADAPTER] Error while fetching metadata with correlation id 7 : {my-example-topic2=UNKNOWN_TOPIC_OR_PARTITION}
[kafka-producer-network-thread | ADAPTER] WARN org.apache.kafka.clients.NetworkClient - [Producer clientId=ADAPTER] Error while fetching metadata with correlation id 8 : {my-example-topic2=UNKNOWN_TOPIC_OR_PARTITION}

我不想通过 AdminClient 检查主题是否存在。Kafka文档https://kafka.apache.org/documentation/#producerconfigs没有帮助。

有办法解决这个问题吗？

Answer 1

当主题不存在时，获取元数据的重试应该在 60 秒后结束，默认情况下最后会引发超时异常。与此相关的生产者配置参数是 max.block.ms(默认 60000)。据我所知，除了减少此超时或使用 AdminClient(这是您不想做的事情)之外，没有其他方法可以更早地获得反馈。