Kafka: auto.offset.reset only applies with no committed offset

It decides where a brand-new group starts, and is ignored once the group has committed anything.

Code

props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");  // or "latest"

Output

earliest: a new group reads the whole retained history
latest:   a new group sees only what arrives after it starts

An existing group resumes from its committed offset either way.