Page History

...

OffsetsForLeaderEpochRequest => [Topic]
  ReplicaId => INT32              // New (-1 means consumer)
  Topic => TopicName [Partition]
    TopicName => STRING
    Partition => PartitionId CurrentLeaderEpoch LeaderEpoch
      PartitionId => INT32
      CurrentLeaderEpoch => INT32
      LeaderEpoch => INT32

When an OffsetsForLeaderEpoch request is received from a consumer, the returned offset will be limited to the high watermark. As with the Fetch API, when a leader has just been elected, the true high watermark is not known for a short time. If an OffsetsForLeaderEpoch request is received with the latest epoch during this window, the leader will respond with the OFFSET_NOT_AVAILABLE error code. This will cause the consumer to retry. Note as well that only leaders are allowed to handle OffsetsForLeaderEpoch queries. 

Consumer Changes

We will expose a new plugin interface that allows the user to provide custom logic to determine the preferred replica to fetch from.

...