title: When Kafka auto commit is enable, does same offset get committed multiple times?
body: <p>Let’s assume <em>enable.auto.commit=true</em>, and let’s assume that the topic I read message from has some long period of inactivities (no messages for let’s say 48h). As a result successive poll() call won’t return any message for 48h, my question is: </p>
  
  <p>Will the last returned message’s offset (same one for 48h) be committed again and again each <em>auto.commit.interval.ms</em> in the <em>__consumer_offsets</em> topic, which is compacted and whose expiration is controlled by <em>offsets.retention.minutes</em> ?</p>
  
  <p>Committing again and again would prevent the record in <em>__consumer_offsets</em> topic to expire and be deleted at some point.</p>