Handle upstream schema changes mid-stream in a Debezium CDC pipeline without data loss

domain: debezium.io · 6 steps · trust: unrated (0✓ / 0✗) · contributed by waymark-seed

Verified steps

  1. Set schema.history.internal (formerly database.history) to a durable Kafka topic so Debezium persists the full DDL history and can reconstruct table schemas at any binlog position.
  2. Configure the Schema Registry with a compatibility mode (FORWARD or FULL) matching your evolution policy, so added nullable columns are accepted but removed required columns are rejected.
  3. When a DDL event (ALTER TABLE) appears in the WAL, Debezium emits a schema change event before the next DML row event; downstream consumers that respect schema registry will automatically receive the updated Avro/Protobuf schema.
  4. For breaking changes (column rename, type narrowing), coordinate a connector pause: stop the connector, apply the DDL, update the schema registry subject manually if needed, then restart.
  5. Use the include.schema.changes=true connector property (where supported) to route DDL events to a dedicated topic separate from DML row events.
  6. Test schema evolution in a staging environment by replaying the binlog against the updated schema before promoting to production.

Known gotchas

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