kafka topics failed UnknownHostException

[M.Z.]

Hi, Guys. Any idea about this error?

I installed and add Kafka service through Cloudera Manager, which looks
fine.

But when I try to test it with list topics, it gave error like:

./kafka-topics.sh --list --zookeeper localhost:2181



java.net.UnknownHostException: opt

at java.net.AbstractPlainSocketImpl.connect(AbstractP
lainSocketImpl.java:178)



I dont where the host 'opt' come from?