I am trying to enable TLS for kafka broker exchanges and had a thought regarding Zookeeper TLS. Currently, on Apache Kafka Documentation I cannot see much mentioned about ZK TLS setup (ok, probably because it's a different apache project) and any possible performance impact.
The question is, can I not have the ONLY broker-client and inter-broker exchanges secured? Do I also need to add TLS to zookeeper? Extra security isn't bad, but is it really necessary to it even for zookeeper?