Hello, Apologies if this question has been asked before. If I understand things correctly a client can only fetch from the leader of a partition, not from an (in-sync) replica. I have a use case where it would be very beneficial if it were possible to fetch from a replica instead of just the leader, and I wonder why it is not allowed? Are there any consistency problems with allowing it, for example? Is there any way to configure Kafka to allow it?
The use case is a Kafka cluster running in EC2 across three availability zones. I would like clients to only fetch from a replica in the same zone to avoid paying for more inter-zone traffic than absolutely necessary. The producer side and the replication will still send traffic across zones, but it would be nice to be able to avoid another zone crossing on the consumer side. We currently have a Kafka cluster that costs about the same in bandwidth cost as running the instances, so every little bit helps. yours, Theo
