NewBarrier create a new barrier for the changefeed.

NewMaintainer create the maintainer for the changefeed.

NewMaintainerManager create a changefeed maintainer manager instance and register message handler to message center.

EventInit initialize the changefeed maintainer.

EventMessage is triggered when a grpc message received.

EventPeriod is triggered periodically, maintainer handle some task in the loop, like resend messages.

Barrier manage the block events for the changefeed note: the dispatcher will guarantee the order of the block event.

BarrierEvent is a barrier event that reported by dispatchers, note is a block multiple dispatchers all of these dispatchers should report the same event.

Controller schedules and balance tables there are 3 main components in the controller, scheduler, ReplicationDB and operator controller.

Event identify the Event that maintainer will handle in event-driven loop.

Maintainer is response for handle changefeed replication tasks.

Manager is the manager of all changefeed maintainer in a ticdc watcher, each ticdc watcher will start a Manager when the watcher is startup.