A city 311 bus starts shipping optional JSON fields for newly added service categories while older mobile apps still consume the topic. What ingestion design best tolerates that schema evolution?
Select an answer to reveal the explanation.
Short Explanation
New optional fields are like extra stickers on a form—older clerks can still read the blanks they know. Design consumers to skip unknown properties instead of crashing. That is how civic event buses evolve without a citywide lockstep upgrade.
Full Explanation
At ingestion, schema evolution is common when municipal producers add categories or attributes over time. Forward-compatible consumers treat unknown fields as ignorable so older apps keep processing known keys. Rigid fixed schemas, nightly rewrites of historical messages, or mandatory simultaneous upgrades create brittle coupling across agencies. Additive optional fields plus tolerant parsing keep the topic flowing while teams upgrade on their own schedules.