我使用的是spring kafka，如果我不设置concurrentkafkalistenercontainerfactory的并发性，当我将其设置为大于1的数字时，我会得到一个异常：
javax.management.instancealreadyexistsexception:Kafka。consumer:type=app-info，id=客户端3
我的配置：

@Bean
public ConcurrentKafkaListenerContainerFactory<String, String> 
    kafkaListenerContainerFactory() {
    ConcurrentKafkaListenerContainerFactory<String, String> factory = new 
    ConcurrentKafkaListenerContainerFactory<String, String>();
    factory.setConcurrency(kafkaConfig.getConcurrency());
    factory.getContainerProperties().setAckMode(AckMode.MANUAL);
    factory.setConsumerFactory(consumerFactory());
    return factory;
}

属性：

kafka.enable-auto-commit=false
kafka.client-id=client-1
kafka.concurrency=2