Kafka BrokerHeartbeat Response Wire Format v0 — Binary Protocol Layout

What is BrokerHeartbeat?

Each broker sends this periodically to the KRaft controller to prove liveness and report metadata replication progress. A broker that stops heartbeating gets fenced and its leadership migrated away. The highestMetadataOffset tells the controller how caught up the broker is before unfencing after a restart.

Schema
{
  "ThrottleTimeMs": int32,
  "ErrorCode": int16,
  "IsCaughtUp": bool,
  "IsFenced": bool,
  "ShouldShutDown": bool
}

Example
{
  "ThrottleTimeMs": 0,
  "ErrorCode": 0,
  "IsCaughtUp": true,
  "IsFenced": true,
  "ShouldShutDown": true
}