向无效主题发送消息时，Spring Kafka 生产者中的无限循环

Question

我正在开发一个 Spring Boot 应用程序。该应用程序充当 Kafka 生产者，其中生产/发布消息不是很重要。我正在使用 spring-kafka 依赖项和 Kafka 的以下配置

    @Bean
public ProducerFactory<String, Object> producerFactory() {
    Map<String, Object> configProps = new HashMap<>();

    configProps.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, kafkaConfig.getKafkaBrokers());
    configProps.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
    configProps.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, JsonSerializer.class);
    configProps.put(ProducerConfig.RETRIES_CONFIG, 3);
    
    return new DefaultKafkaProducerFactory<>(configProps);
}

@Bean
public KafkaTemplate<String, Object> kafkaTemplate(ProducerFactory<String, Object> producerFactory) {
    return new KafkaTemplate<>(producerFactory);
}

当我向不存在的主题发送消息时。我的应用程序显示以下日志

17:18:45.187 [kafka-producer-network-thread | producer-1] WARN  org.apache.kafka.clients.NetworkClient - [] [Producer clientId=producer-1] Error while fetching metadata with correlation id 3 : {aksubd=UNKNOWN_TOPIC_OR_PARTITION}
17:18:45.347 [kafka-producer-network-thread | producer-1] WARN  org.apache.kafka.clients.NetworkClient - [] [Producer clientId=producer-1] Error while fetching metadata with correlation id 4 : {aksubd=UNKNOWN_TOPIC_OR_PARTITION}
17:18:45.522 [kafka-producer-network-thread | producer-1] WARN  org.apache.kafka.clients.NetworkClient - [] [Producer clientId=producer-1] Error while fetching metadata with correlation id 5 : {aksubd=UNKNOWN_TOPIC_OR_PARTITION}
17:18:45.687 [kafka-producer-network-thread | producer-1] WARN  org.apache.kafka.clients.NetworkClient - [] [Producer clientId=producer-1] Error while fetching metadata with correlation id 6 : {aksubd=UNKNOWN_TOPIC_OR_PARTITION}
17:18:45.864 [kafka-producer-network-thread | producer-1] WARN  org.apache.kafka.clients.NetworkClient - [] [Producer clientId=producer-1] Error while fetching metadata with correlation id 7 : {aksubd=UNKNOWN_TOPIC_OR_PARTITION}
17:18:46.035 [kafka-producer-network-thread | producer-1] WARN  org.apache.kafka.clients.NetworkClient - [] [Producer clientId=producer-1] Error while fetching metadata with correlation id 8 : {aksubd=UNKNOWN_TOPIC_OR_PARTITION}
17:18:46.203 [kafka-producer-network-thread | producer-1] WARN  org.apache.kafka.clients.NetworkClient - [] [Producer clientId=producer-1] Error while fetching metadata with correlation id 9 : {aksubd=UNKNOWN_TOPIC_OR_PARTITION}
17:18:46.378 [kafka-producer-network-thread | producer-1] WARN  org.apache.kafka.clients.NetworkClient - [] [Producer clientId=producer-1] Error while fetching metadata with correlation id 10 : {aksubd=UNKNOWN_TOPIC_OR_PARTITION}
17:18:46.546 [kafka-producer-network-thread | producer-1] WARN  org.apache.kafka.clients.NetworkClient - [] [Producer clientId=producer-1] Error while fetching metadata with correlation id 11 : {aksubd=UNKNOWN_TOPIC_OR_PARTITION}
17:18:46.715 [kafka-producer-network-thread | producer-1] WARN  org.apache.kafka.clients.NetworkClient - [] [Producer clientId=producer-1] Error while fetching metadata with correlation id 12 : {aksubd=UNKNOWN_TOPIC_OR_PARTITION}
17:18:46.888 [kafka-producer-network-thread | producer-1] WARN  org.apache.kafka.clients.NetworkClient - [] [Producer clientId=producer-1] Error while fetching metadata with correlation id 13 : {aksubd=UNKNOWN_TOPIC_OR_PARTITION}
17:18:47.055 [kafka-producer-network-thread | producer-1] WARN  org.apache.kafka.clients.NetworkClient - [] [Producer clientId=producer-1] Error while fetching metadata with correlation id 14 : {aksubd=UNKNOWN_TOPIC_OR_PARTITION}
17:18:47.233 [kafka-producer-network-thread | producer-1] WARN  org.apache.kafka.clients.NetworkClient - [] [Producer clientId=producer-1] Error while fetching metadata with correlation id 15 : {aksubd=UNKNOWN_TOPIC_OR_PARTITION}

日志处于无限循环中（我只显示开始的几个日志）。我故意给出一个不存在的无效主题“aksubd”只是为了证明这个问题。我是 kafka 的新手，想知道这是否是 Kafka 的正常行为，因为这可能会写入不必要的日志。我不希望应用程序无限记录。有没有办法在配置中设置一定数量的重试后停止，然后在控制台上抛出错误？注意：我尝试将重试次数设置为 3，但没有成功。

Answer 1

确实，这是预期的行为。

如果您在代理上有auto.create.topics.enable=true，那么主题将在生产者请求时创建，但建议禁用此功能，因为客户端可能会输入主题名称，然后想知道他们的数据实际上在哪里结束。尽管名称如此，retries 并不适用于元数据请求，仅适用于生产者批处理请求。

如果您想事先检查某个主题，请在生成主题之前使用 AdminClient 对其进行描述。