A Spring self-check on configuration binding, validation and expand/backfill/contract database phases.
Review before answering
- Spring Boot command-line properties: test the effective value at startup
- Spring Boot Duration binding: make timeout units explicit
- Spring Boot configuration validation: reject an unusable relay before work starts
- Spring database rollout: add a nullable column before changing every writer
- Spring database backfill: assign historical rows before enforcing ownership
- Spring database contract phase: reject old writers only after backfill
- Spring Boot migrations: what a versioned runner must add to the SQL test
File and migration checks
- Spring Boot external config file: bind the value the process actually loads
- Spring Boot file versus command line: assert the bound result
- Flyway SQL migrations: record ordered schema changes against a real database
- Flyway expand and contract: show exactly when an old writer breaks
- Flyway validation: detect a changed applied migration before another write
Common Mistakes
- Do not mistake a default for the effective setting.
- Do not contract a schema while old writers still run.
- Keep the direct SQL test separate from the newer Flyway migration test.