老师您好，我用kafka测试代码dropPassTemplate，我分别安装了windows版本的kafka和centos7版本的kafka，用的同样的安装包。 在window版本测试都正常，可以消费到json格式的数据，跟您课程里面效果一样。但是在centos环境下，报了下面这样的错。我把相应的地址设置也都改了。查了百度一圈，试了不同的kafka版本jar包，也还是不行。谢谢老师。

2019-03-10 19:09:56.461  WARN 183484 --- [ad | producer-1] org.apache.kafka.clients.NetworkClient   : [Producer clientId=producer-1] Connection to node -1 could not be established. Broker may not be available.

2019-03-10 19:09:57.346 ERROR 183484 --- [           main] o.s.k.support.LoggingProducerListener    : Exception thrown when sending a message with key='merchants-template' and payload='{"background":2,"desc":"详情: 慕课","end":1553080136400,"hasToken":false,"id":19,"limit":10000,"start":1...' to topic merchants-template:

org.apache.kafka.common.errors.TimeoutException: Failed to update metadata after 60000 ms.

2019-03-10 19:09:57.348  INFO 183484 --- [           main] c.i.p.service.impl.MerchantsServImpl     : DropPassTemplates: {"background":2,"desc":"详情: 慕课","end":1553080136400,"hasToken":false,"id":19,"limit":10000,"start":1551352136398,"summary":"简介: 慕课","title":"慕课-1"}

{"errorCode":0,"errorMsg":""}

2019-03-10 19:09:57.358  INFO 183484 --- [       Thread-3] s.c.a.AnnotationConfigApplicationContext : Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@71a8adcf: startup date [Sun Mar 10 19:08:47 CST 2019]; root of context hierarchy

2019-03-10 19:09:57.360  INFO 183484 --- [       Thread-3] o.s.c.support.DefaultLifecycleProcessor  : Stopping beans in phase 2147483547

2019-03-10 19:09:57.360  INFO 183484 --- [       Thread-3] o.s.c.support.DefaultLifecycleProcessor  : Stopping beans in phase 0

2019-03-10 19:09:57.362  INFO 183484 --- [       Thread-3] o.a.k.clients.producer.KafkaProducer     : [Producer clientId=producer-1] Closing the Kafka producer with timeoutMillis = 30000 ms.

2019-03-10 19:09:57.372  INFO 183484 --- [       Thread-3] j.LocalContainerEntityManagerFactoryBean : Closing JPA EntityManagerFactory for persistence unit 'default'

Process finished with exit code 0