Zookeeper has a simple management interface that we can use to check cluster health, list keys, etc. The management commands are collectively known as the Four-Letter Words.
Starting with version 3.4.10 , Zookeeper blocks these commands by default, responding with ${cmd} is not executed because it is not in the whitelist. We're running into this on Bookworm, which ships with 3.8.0-11.
As we need these commands to have visibility into the cluster, I'm creating this ticket to:
- Enable these commands in zoo.cfg for newer versions of Zookeeper.
- Verify operation.