Does log.retention.bytes apply only to partition leader or also replicas

[David Corley <da...@gmail.com>]

Does the byte retention policy apply to replica partitions or leader
partitions or both?
In a multi-node cluster, with all brokers configured configured with
different retention policies, it seems obvious that the partitions for
which a given broker is a leader will be subject to the byte retention
policy, but what about the partitions for which the given broker is a
replica? Are they subject to the same policy?

For example, a 2 node cluster with single topic and two partitions.
Broker A is the leader for partition 1 and contains the replica of
partition 2
Broker B is the leader for partition 2 and contains the replica of
partition 1
Broker A has a byte retention policy of 1 byte
Broker B has a byte retention policy of 2 bytes

Will broker A retain 1 byte of of both partitions it hosts?
Likewise, will broker B retain 2 bytes of both partitions it hosts?