• If this group ID is started for the first time, it ignores the previously sent messages. That is, the group ID ignores the historical messages and starts consumption after its own startup.
  • If the group ID is started for the second time, it starts consumption from the previous consumption offset.
  • If you want to start consumption from a specific offset, you can use the consumption offset reset function in the Message Queue for Apache RocketMQ console and specify the consumption start time. Each reset only affects the specific topic under the specific group ID and does not affect other group IDs.