启动kafka时 报错：
kafka-console-consumer.sh --from-beginning --zookeeper node01:8121,node02:8121,node03:8121 --topic log_monitor
Using the ConsoleConsumer with old consumer is deprecated and will be removed in a future major release. Consider using the new consumer by passing [bootstrap-server] instead of [zookeeper].
[2019-08-04 10:03:45,906] WARN Session 0x0 for server null, unexpected error, closing socket connection and attempting reconnect (org.apache.zookeeper.ClientCnxn)
java.net.ConnectException: Connection refused
将zk端口号修改为9092，报另一个错误：
[2019-08-04 10:04:17,647] WARN Client session timed out, have not heard from server in 10006ms for sessionid 0x0 (org.apache.zookeeper.ClientCnxn)
[2019-08-04 10:04:28,461] WARN Client session timed out, have not heard from server in 10004ms for sessionid 0x0 (org.apache.zookeeper.ClientCnxn)
[2019-08-04 10:04:39,418] WARN Client session timed out, have not heard from server in 10001ms for sessionid 0x0 (org.apache.zookeeper.ClientCnxn)
No brokers found in ZK.
原因：检查发现是zk的端口号写错了，写成了8121，或者 9092。
解决方法：将端口号修改为2181.