Offset and lag for kafka consumer (created via new consumer api) are set to unknown
<p>I am often seeing issue in which kafka consumer gets current offset and lag set to unknown<br>
Earlier consumer was having offset and lag  </p>

<pre><code>GROUP, TOPIC, PARTITION, CURRENT OFFSET, LOG END OFFSET, LAG, OWNER  
G.AB_KAFF, T.AB_KAFF, 0, 3, 6, 3, consumer-2
G.AB_KAFF, T.AB_KAFF, 1, 8, 11, 3, consumer-2
</code></pre>

<p>When I subscribed this consumer again after few days its offset and lag is set to unknown  </p>

<pre><code>GROUP, TOPIC, PARTITION, CURRENT OFFSET, LOG END OFFSET, LAG, OWNER  
G.AB_KAFF, T.AB_KAFF, 0, unknown, 7, unknown, consumer-2
G.AB_KAFF, T.AB_KAFF, 1, unknown, 11, unknown, consumer-2  
</code></pre>

<p>Is kafka removing previous offsets for that consumer since I am unsubscribing whole consumer group from topic ?  </p>