Hi Chia-Ping, Thanks for pointing me to the KIP process.
My understanding is that the issue here is that controller-only nodes expose a metric tag named BrokerId, which is misleading for that role. Since this affects exported metrics, I agree this likely needs a KIP discussion. Also, this JIRA is currently assigned to me, so I started exploring a possible fix in the PR. I’m happy to draft a KIP and start the discussion if that’s the preferred path. Thanks, Nilesh
