As detailed in the upstream issue Migrate off internal Kafka APIs to Improve Compatibility and Maintainability #2282, the existing Cruise Control tests rely on the Kafka server wrapper class, CCEmbeddedBroker, which uses several non-public Kafka APIs. These internal APIs lack stability and compatibility guarantees, making it increasingly difficult to upgrade Kafka versions.

This task is to refactor CCKafkaClientsIntegrationTestHarness and subclasses to replace all usages of the CCEmbeddedBroker class and thus remove its dependence on private Kafka APIs and make it easier to test against different Kafka versions.