[takeda]

In order to connect a ZK host to the cluster its IP needs to be included in configuration of all the nodes.

It's hard to accidentally add node to a cluster. A person who can "accidentally" add a ZK node has enough permission to do a lot of more devastating things accidentally.

[erulabs]

Yep. All it takes is service discovery and a not-totally-familiar with ZK jr. sysadmin.

This is all in service to my point about simplicity and safety.