[KAFKA-8409] Seperate controller thread/manager events from controller events

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.4.0
• Component/s: controller
• Assignee: Jose Armando Garcia Sancio
• Reporter: Jose Armando Garcia Sancio
• Created: 22/May/19 19:59
• Updated: 22/May/19 19:59

Description

The ControllerEventManager and the KafkaController are driven by processing ControllerEvent in the queue. As of right now the ControllerEventManager is responsible for handling ShutdownEventThread while the KafkaController handles all other events. Since we are using a sealed trait the scala compiler is able to check that all cases are handle in match expressions.

To by pass this compiler feature the KafkaController is matching on ShutdownEventThread and ignoring the result. We should instead create two type of events. For example:

sealed trait ControllerThreadEvent
final case object ShutdownEventThread extends ControllerThreadEvent
final case class ControllerEvent(event: ControllerEvent) extends ControllerThreadEvent

And remove ShutdownEventThread from the ControlleveEvent sealed trait.