title: validation for kafka topic messages
body: <p>I'm working with kafka and I've been asked with doing a validation of the message that are sent to Kafka, but I don't like the solutions I've thought that's why I hope someone can advice me on this.</p>
  
  <p>We have many producers outside our control, so they can send any message with any kind of format, and we could have as much as 80 million records sent, and they should be dealt in less than 2 hours.
  I'v been asked to:</p>
  
  <ul>
  <li><p>Validate the format (Json since it has to be compatible with mongoDB).</p></li>
  <li><p>Validate some of the fields sent.</p></li>
  <li><p>Rename some fields</p></li>
  </ul>
  
  <p>The last 2 requestes are to be done using parameters stored in MongoDB.
  All of this should be done assuming we are not the only one making the consumers,   so there should be a "simple" call to our service that makes this validation.
  Any ideas?</p>