title: Consumer not be able to poll message from Kafka
body: <p>I started two consumers to consume messages from Kafka, there were six partitions, so each consumer was assigned three partitions. I found the consumers could not poll any messages after consuming a while, I could see the lag was there, that means there were still unpolled messages.</p>
  
  <p>When I killed the program and restarted it, the consumers could consume the remaining messages, but after a while, it stopped again although there were remaining messages. </p>
  
  <p>There were no any error messages, part of my code as following please:</p>
  
  <pre><code> KafkaConsumer&lt;String, byte[]&gt; consum = new KafkaConsumer&lt;String, byte[]&gt;(props);
   ConsumerRecords&lt;String, byte[]&gt; records = kconsumer.poll(timeoutInMS);
  </code></pre>
  
  <p>I started two threads in one JVM, each thread will create itself KafkaConsumer.</p>
  
  <p>I used AsyncCommit,and I set the callback class is null. such as:</p>
  
  <pre><code>Map&lt;TopicPartition, OffsetAndMetadata&gt; offsets = ...;
  consumer.commitAsync(offsets, null);
  </code></pre>
  
  <p>Did this caused the issue please?</p>