Memory hook: A migration moves a workload; adoption also changes people, process and governance.
Must remember
- The Cloud Adoption Framework groups concerns into business, people, governance, platform, security and operations perspectives. A technically successful migration can fail its business case if skills, accountability or cost ownership are missing.
- Recognise the migration strategies: retire what is unnecessary; retain what stays; rehost with minimal change; relocate supported infrastructure; repurchase a replacement product; replatform with selected platform changes; refactor/re-architect for a new design. Pick the smallest justified change that meets the business requirement.
- Application Migration Service supports server migration through replication. DMS moves database data, including supported ongoing replication. DataSync transfers file/object data between supported locations. Transfer Family exposes managed transfer protocols such as SFTP for supported storage.
- Discover dependencies before choosing migration waves. Assess licensing, data residency, connectivity, downtime and rollback. The lowest migration effort is not always the lowest long-term operating cost.
- The console is graphical; CLI and SDKs call service APIs programmatically. CloudShell offers a browser-based command environment using your authorised identity. These interfaces do not bypass IAM.
- CloudFormation provisions declared infrastructure from templates. Infrastructure as code supports repeatable changes and review. Systems Manager supports administration such as session access, inventory, patching and automation. Elastic Beanstalk automates deployment of supported application platforms.
- CodePipeline orchestrates delivery; CodeBuild builds/tests; CodeDeploy automates supported deployment targets. AWS Backup centrally organises backup policies. Recovery objectives and tests are part of the operating design, not a final checkbox.
- Snow-family/offline-transfer references may appear in older course material. Check current customer eligibility rather than assuming an old service can still be ordered. No physical transfer job is required to revise this concept.
Choose under exam pressure
| Requirement | Choice and reason |
|---|---|
| Move servers with little redesign | Rehost using an appropriate migration mechanism. |
| Replace a legacy CRM with SaaS | Repurchase. |
| Recreate the same infrastructure in several environments | Infrastructure as code. |
Traps
- Copying database rows does not convert every stored procedure.
- A console operation and a CLI operation need equivalent authorisation.
- A completed migration is not proof of a tested rollback or recovery procedure.
Active recall
1. Which migration strategy removes an unused application?
Retire.
2. Which CAF perspective deals with workforce capability?
People.
3. Why discover application dependencies first?
Moving one tier before required dependencies can break the service; dependencies guide migration waves and testing.
4. Does CloudFormation remove all responsibility for generated resources?
No. You still own the template, permissions, design and resulting charges.
5. What is the difference between a one-off console change and IaC?
IaC records an intended configuration that can be reviewed and reproduced; manual actions need their own controls and records.