Page History

...

Kafka's controller currently has no visibility into each broker's static configuration. When a broker registers with the controller via BrokerRegistrationRequest, it reports its supported feature versions, listeners, rack, and log directories, but not its configuration values (i.e., the settings defined in server.properties). This creates a fundamental gap that blocks two categories of improvements:

This gap is not hypothetical — it has already produced observable technical debt in trunk. [KAFKA-20544] tracks  tracks the refactor of cordoned.log.dirs validation in ConfigurationControlManager, whose description explicitly states that the cleanup depends on making static configurations available in the controller. Today, because the controller cannot see each broker's log.dirs, validating cordoned.log.dirs ⊆ log.dirs requires a resource-specific code path inside ConfigurationControlManager and a forwarded flag plumbed through the Controller interface — a workaround that the standard ConfigDef validator path should have made unnecessary. KAFKA-20544 is concrete evidence that the missing static configuration data is already shaping controller code in undesirable ways, and removing it is the prerequisite for that cleanup.

...