Page History

...

Current state: "Vote"

Discussion thread: here 

Vote thread: here 

JIRA: here

Please keep the discussion on the mailing list rather than commenting on the wiki (wiki discussions get unwieldy fast).

...

1. Follower

   • The follower will send its epoch id (received when registering) in the Fetch request.

2. Leader

   • The leader will keep track of the follower epochs received through the Fetch request. The epochs can be maintained in the ReplicaState.

   • The leader will include the proposed ISR follower epochs in the AlterPartition request. Also, the leader will verify these epochs against the metadata cache. Before the broker epochs from the Fetch request and the metadata cache are consistent, the leader will not propose to include the broker in the ISR.

   • The leader will discard the proposed ISR change and revert to the old committed ISR if the controller returns INELIGIBLE_REPLICA for the partition.

3. Controller

   • The controller will make sure all the broker epochs in the ISR match with the latest broker epochs before persisting this change. If not, it will reject the request with the error code INELIGIBLE_REPLICA.

...