title: Spring Kafka producer not work asynchronous
body: <p>I'm using a non Blocking (Async) sending message to Kafka using this : </p>
  
  <pre><code>    ListenableFuture&lt;SendResult&lt;Integer, String&gt;&gt; future = template.send(record);
      future.addCallback(new ListenableFutureCallback&lt;SendResult&lt;Integer, String&gt;&gt;() {
  
          @Override
          public void onSuccess(SendResult&lt;Integer, String&gt; result) {
              handleSuccess(data);
          }
  
          @Override
          public void onFailure(Throwable ex) {
              handleFailure(data, record, ex);
          }
  
      });
  </code></pre>
  
  <p>This work perfectly when the send action does its work.</p>
  
  <p>But when there is a connection problem (server down for example), the result <strong>become non asynchronous</strong> and the method remains blocked until the end of the duration of max.block.ms.</p>