You have a Kafka consumer in production actively reading from a critical topic.

To reset offsets for an existing consumer group, you must use the kafka-consumer-groups.sh tool with the --reset-offsets and --to-earliest flags.

From Kafka Consumer Group Tool Documentation:

“You can use the kafka-consumer-groups tool to reset offsets for a consumer group. This is required if the consumer has already committed offsets.”

Setting auto.offset.reset=earliest only works if no committed offset exists.

Starting a new consumer with the same group won’t reset offsets.

Retention settings don’t affect committed offsets.