title: How to acknowledge consume message in kafka using php-rdkafka?
body: <p>I am using <a href="https://github.com/arnaud-lb/php-rdkafka" rel="noreferrer">php-rdkafka</a> as php kafka client. I successfully product my test message by using <code>test</code> group.and consume the message by using below code,</p>
  
  <pre><code>$kafkaConsumer = new RdKafka\Consumer();
  $kafkaConsumer-&gt;addBrokers("127.0.0.1:9292");
  $topic = $kafkaConsumer-&gt;newTopic("test");
  $topic-&gt;consumeStart(0, RD_KAFKA_OFFSET_BEGINNING);
  
  while (true) {
      $msg = $topic-&gt;consume(0, 1000);
      if($msg){
      if ($msg-&gt;err) {
          echo $msg-&gt;errstr(), "\n";
          break;
      } else {
          echo $msg-&gt;payload, "\n";
      }
    }
  }
  </code></pre>
  
  <p>But when I try to again set message in <code>test</code> group and trying to consume message for <code>test</code> group then I am getting old message as well as new message. So I just want to how can I acknowledge old message so I can get only new message not old one ? Can someone put some shine on this ?</p>
  
  <p>My kafka version is <code>0.11.0.1</code></p>