title: About Kafka producer error handler stagey
body: <p>I'm hesitating that should I use Kafka producer Async or Sync API, I prefer ASync API, but when there is an exception, it's hard to catch it up. I wrote a CallBack Function to remember the failed messages, and then save them to database.</p>
  
  <p>If I used Sync API, I have to design some Exception Classes to catch some specific Exceptions and use suitable failure handler logic.</p>
  
  <p>So from failure handle perspective, which API should I use, Sync or Async?   </p>