title: Producing a Kafka message with a Null Value (Tombstone) from the Console
body: <p>Is there any way to produce a message in the kafka-console-producer with a null value (ie. mark it for the compactor to delete it with a tombstone)?</p>
  
  <p>I've tried producing "mykey" and "mykey|".  The former produces an error and the later makes the value the empty string.  Running producer like this:</p>
  
  <pre><code>$KAFKA_HOME/bin/kafka-console-producer --broker-list localhost:9092 --topic mytopic --property "parse.key=true" --property "key.separator=|"
  </code></pre>