Kafka BrokerRegistration Response Wire Format v4 — Binary Protocol Layout

What is BrokerRegistration?

A broker sends this on startup in KRaft mode to register with the active controller. The incarnation UUID changes on every restart, letting the controller distinguish a restart from a slow broker and prevent two instances of the same broker ID from both being active.

Schema
{
  "ThrottleTimeMs": int32,
  "ErrorCode": int16,
  "BrokerEpoch": int64
}

Example
{
  "ThrottleTimeMs": 0,
  "ErrorCode": 0,
  "BrokerEpoch": 12
}