Kafka UpdateFeatures Request Wire Format v0 — Binary Protocol Layout

What is UpdateFeatures?

Finalizes feature version flags during cluster upgrades via kafka-features.sh. After all brokers support a new feature version, an operator calls this to activate it. Some features (like the new consumer group protocol) are gated behind feature flags and require explicit activation.

Schema
{
  "timeoutMs": int32,
  "FeatureUpdates": [{
      "Feature": string,
      "MaxVersionLevel": int16,
      "AllowDowngrade": bool
  }]
}

Example
{
  "timeoutMs": 30000,
  "FeatureUpdates": [{
      "Feature": "kraft.version",
      "MaxVersionLevel": 1,
      "AllowDowngrade": true
  }]
}