title: Does kafka distinguish between consumed offset and commited offset?
body: <p>From what I understand a consumer reads messages off a particular topic, and the consumer client will periodically commit the offset.</p>
  <p>So if for some reason the consumer fails a particular message, that offset won't be committed and you can then go back and reprocess he message.</p>
  <p>Is there anything that tracks the offset you just consumed and the offset you then commit?</p>