[KAFKA-12982] Notify listeners of raft client shutdowns

• Type: Sub-task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Assignee: HaiyuanZhao
• Reporter: Jose Armando Garcia Sancio
• Created: 22/Jun/21 21:58
• Updated: 04/Jul/21 08:54

Description

`RaftClient.Listener.beginShutdown` should be called when the `RaftClient` is shutting down. I think there should be two ways to terminate the `RaftClient`. Those are `shutdown` and `close`.

It looks like the current code for `close` only closes the metrics registry. It doesn't notify the listeners that the raft client was close. It doesn't stop future `poll` from updating the raft client.

There is also an assumption that `shutdown` can only be called once. I think to satisfy this we should remove this method from `RaftClient` and keep it as implementation method in `KafkaRaftClient`.