According to recommended practice, before producing new events with a new schema, you should upgrade which?

According to recommended practice, before producing new events with a new schema, you should upgrade which?

• A. Producers
• B. Consumers
• C. Both Producers and Consumers
• D. None

Answer: (B)

Introducing a new schema for future events changes the shape of the data that consumers must interpret. Upgrading the consumers first ensures they have the updated deserializers and processing logic to handle the new fields, types, and any defaults or optional elements introduced by the schema change. If producers start emitting with the new schema while consumers still use the old decoding, those messages may fail to deserialize or be misinterpreted, causing errors in processing. By updating consumers ahead of production with the new schema, you create a safe migration path where downstream applications can properly read and process the new payloads, and you can then phase in producers to emit according to the updated schema without breaking consumption.

Introducing a new schema for future events changes the shape of the data that consumers must interpret. Upgrading the consumers first ensures they have the updated deserializers and processing logic to handle the new fields, types, and any defaults or optional elements introduced by the schema change. If producers start emitting with the new schema while consumers still use the old decoding, those messages may fail to deserialize or be misinterpreted, causing errors in processing. By updating consumers ahead of production with the new schema, you create a safe migration path where downstream applications can properly read and process the new payloads, and you can then phase in producers to emit according to the updated schema without breaking consumption.