Also two variants here:
- FORWARD - Consumers with previous version of the schema (X - 1) can read data produced by Producers with a new schema version (X)
- FORWARD_TRANSITIVE - Consumers with any previous version of the schema (X - 1, X - 2, ...) can read data produced by Producers with a new schema version (X)
The operations that preserve forward compatibility are:
- Adding a new field
- Consumers will ignore the fields that are not defined in their schema version
- Deleting optional fields (with default values)
- Consumers will use the default value for the missing fields defined in their schema version
