Schema Registry and Data Validation

Schema Registry Role

1. Validation

   • Rejects incompatible schema changes
   • Validates before data reaches Kafka
   • Maintains schema version history

2. Schema Evolution

   • Forward compatibility: New schema readable by old consumers
   • Backward compatibility: Old schema readable by new consumers
   • Full compatibility: Both forward and backward

3. Client Integration

   • KafkaAvroSerializer for producers
   • KafkaAvroDeserializer for consumers
   • Local schema caching for performance

Best Practices

1. Plan schema evolution strategy upfront
2. Test schema changes before production
3. Monitor schema registry metrics
4. Consider compatibility settings per topic

References

Flashcards

What happens when KafkaAvroDeserializer can't find schema in local cache?:: Fetches schema from Schema Registry

Adding a field without default in Avro is what type of schema evolution?:: Forward compatibility - old consumers can still read new records

Which component rejects incompatible schema changes?:: The Schema Registry, before data reaches Kafka brokers