In this chapter, we showed, instead of sending data in JSON format, how to use AVRO as the serialization format. The main benefit of AVRO (over JSON, for example) is that the data must conform to the schema. Another advantage of AVRO over JSON is that the messages are more compact when sent in binary format, although JSON is human readable.
The schemas are stored in the Schema Registry, so that all users can consult the schema version history, even when the code of the producers and consumers for those messages is no longer available.
Apache Avro also guarantees backward and forward compatibility of all messages in this format. Forward compatibility is achieved following some basic rules, such as when adding a new field, declaring its value as optional.
Apache Kafka encourages the use of Apache Avro and the Schema Registry for the storage of all data and schemas in Kafka...