故障描述：
上周云服务器重启了，上面的kafka再启动时就报错“Caused by: java.net.UnknownHostException: Cent65: Cent: Name or service not known”
而且看kafka-monitor，也不再群集里。
解决办法：在本机hosts解析添加主机名解析，再启动时恢复了。
事后分析原因：
查看kafka日志，发现报错是[2023-08-04 ] INFO Client environment:host.name=<NA> (org.apache.zookeeper.ZooKeeper
host.name是NA，怀疑当时启动时没有看环境变量，会不会当时主机名没有呢？因为系统上线部署时开发都没添加hosts主机名解析，后来咨询云平台主机名可以同网段自己解析，所以没添加。
补充：在3台服务器都添加本地hosts解析，以免出现此种情况
- UnknownHostException Cent service Caused kafkaunknownhostexception cent service caused unknownhostexception spring kafka bcfcc cent cent-os unknownhostexception unknownhostexception静态windows图片 unknownhostexception cloud-member member cloud caused cent-os建站cent os unknownhostexception finalshell node2 java