Courts case-management plans a blue-green app swap, but the database schema is also changing. What caution still applies?
Select an answer to reveal the explanation.
Short Explanation
Blue-green flips the courts app doors, but the filing cabinets (schema) still have to make sense to both lobbies during the handoff. A DNS flip is not a free pass on migrations.
Full Explanation
Blue-green application swaps still require data and schema compatibility across the cutover window so both environments can operate against the shared (or replicated) data plane. Courts case-management systems that change schema while flipping the app must plan migrations that old and new app versions can tolerate during coexistence and rollback. The load-balancer flip moves app traffic; it does not automatically make incompatible SQL safe.
Assuming the load-balancer flip alone guarantees schema safety with no migration plan fails by concept because routing does not rewrite data contracts. Ignoring database compatibility because blue-green only ever touches static HTML fails because case-management is a data-backed app, not a static brochure site. Dropping the old schema immediately before green is proven under citizen traffic fails by removing rollback compatibility and risking broken reads from blue if switchback is needed.
Exam caveat: expand-contract (additive then cleanup) migrations are a common pattern so blue and green can both run during cutover. The exam often tests whether you recognize that blue-green does not eliminate database change management. Treat schema planning as part of the cutover, not an afterthought.
Operational check: rehearse courts cutover in staging with both app versions talking to the migrated schema, verify blue still works for rollback, flip to green, and only schedule destructive schema cleanup after green is proven and blue is decommissioned.