An existing pipeline deploys schema-changing revisions. Concurrent executions can finish out of order and install an older revision last. Which control should be evaluated?

1. Retry older executions indefinitely after newer releases succeed.
2. Allow unrestricted parallel execution and assume completion order equals commit order.
3. Generate random release identities and discard all source revision metadata.
4. Use an execution mode and deployment serialization strategy that preserves the required release order, with version-aware deployment checks.