0.11.0.0版本的kafka使用sasl/scram认证（单独搭建的zk集群且zk未进行认证配置），kafka集群能启动，但一直warn日志，求大神帮忙解决

server.log一直刷的警告信息是：

WARN Connection to node 2 terminated during authentication. This may indicate that authentication failed due to invalid credentials. (org.apache.kafka.clients.NetworkClient)

controller.log中的对应报错信息是：

[2020-06-18 19:35:07,285] INFO [Controller 0]: Newly added brokers: 0, deleted brokers: , all live brokers: 0 (kafka.controller.KafkaController)
[2020-06-18 19:35:07,287] DEBUG [Channel manager on controller 0]: Controller 0 trying to connect to broker 0 (kafka.controller.ControllerChannelManager)
[2020-06-18 19:35:07,295] INFO [Controller-0-to-broker-0-send-thread]: Starting (kafka.controller.RequestSendThread)
[2020-06-18 19:35:07,296] INFO [Controller 0]: New broker startup callback for 0 (kafka.controller.KafkaController)
[2020-06-18 19:35:07,520] WARN [Controller-0-to-broker-0-send-thread]: Controller 0's connection to broker 172.21.4.112:9086 (id: 0 rack: null) was unsuccessful (kafka.controller.RequestSendThread)
java.io.IOException: Connection to 172.21.4.112:9086 (id: 0 rack: null) failed.
at org.apache.kafka.clients.NetworkClientUtils.awaitReady(NetworkClientUtils.java:68)
at kafka.controller.RequestSendThread.brokerReady(ControllerChannelManager.scala:264)
at kafka.controller.RequestSendThread.doWork(ControllerChannelManager.scala:218)
at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:64)