The Retain migration strategy, also known as 'Revisit' or 'Do Nothing,' is one of the 7 Rs of migration strategies within AWS's Cloud Adoption Framework. This approach involves keeping certain applications in their current on-premises environment rather than moving them to the cloud at the present …The Retain migration strategy, also known as 'Revisit' or 'Do Nothing,' is one of the 7 Rs of migration strategies within AWS's Cloud Adoption Framework. This approach involves keeping certain applications in their current on-premises environment rather than moving them to the cloud at the present time.
Organizations choose the Retain strategy for several compelling reasons. First, some applications may have regulatory or compliance requirements that necessitate on-premises hosting. Second, applications nearing end-of-life or scheduled for decommissioning may not justify migration investment. Third, certain workloads might require significant refactoring that exceeds current budget or timeline constraints.
The Retain strategy is particularly applicable when applications have complex dependencies that cannot be easily resolved, when there are unresolved licensing issues with cloud deployment, or when the business case for migration does not demonstrate sufficient return on investment. Organizations might also retain applications that rely on legacy hardware or software that lacks cloud-compatible alternatives.
Implementing the Retain strategy requires proper documentation and periodic reassessment. Teams should maintain detailed records of why specific applications were retained, including technical limitations, business constraints, and planned future actions. Regular reviews ensure that retained applications are reconsidered as cloud services evolve and organizational requirements change.
From an architectural perspective, retained applications may still benefit from hybrid connectivity solutions. AWS services like AWS Direct Connect or AWS VPN can establish secure connections between retained on-premises systems and cloud-migrated workloads, enabling data exchange and integration.
The Retain strategy should be viewed as a temporary classification rather than a permanent decision. As AWS continues expanding its service offerings and as organizations mature their cloud capabilities, previously retained applications often become candidates for migration through other strategies such as Rehost, Replatform, or Refactor in subsequent migration waves.
Retain Migration Strategy - AWS Solutions Architect Professional
What is the Retain Migration Strategy?
The Retain migration strategy, also known as Revisit, is one of the 7 Rs of cloud migration strategies. It refers to the decision to keep certain workloads in their current environment rather than migrating them to AWS at the present time. This strategy acknowledges that not every application or system is ready or suitable for immediate cloud migration.
Why is Retain Important?
Understanding the Retain strategy is crucial because:
• Cost Optimization: Migrating applications that don't benefit from cloud capabilities wastes resources and budget • Risk Management: Some legacy systems may be too complex or risky to move at a given time • Business Prioritization: Organizations must focus migration efforts on applications that provide the highest business value • Compliance Requirements: Certain regulatory or contractual obligations may require on-premises hosting • End-of-Life Planning: Applications scheduled for retirement don't justify migration investment
When to Use the Retain Strategy
Consider Retain when:
• Recent Infrastructure Investments: Applications running on newly purchased hardware that hasn't been fully depreciated • Unresolved Dependencies: Systems with complex dependencies that haven't been fully mapped or understood • Compliance Restrictions: Regulatory requirements mandating on-premises data residency • Pending Retirement: Applications planned for decommissioning within 12-24 months • Lack of Business Case: No clear ROI or benefit from migrating specific workloads • Technical Limitations: Legacy systems incompatible with cloud architecture requiring significant rework
How Retain Works in Practice
The Retain strategy involves:
1. Assessment: Evaluate each application against migration criteria 2. Documentation: Record reasons for retention and future review dates 3. Hybrid Architecture: Establish connectivity between retained on-premises systems and AWS using VPN or AWS Direct Connect 4. Periodic Review: Regularly reassess retained workloads for migration readiness 5. Dependency Management: Ensure retained systems can communicate with migrated workloads
Key AWS Services for Hybrid Scenarios
When implementing Retain alongside other migration strategies:
• AWS Direct Connect: Dedicated network connection between on-premises and AWS • AWS VPN: Encrypted connectivity over the internet • AWS Outposts: Extends AWS infrastructure to on-premises locations • AWS Storage Gateway: Hybrid cloud storage integration
Exam Tips: Answering Questions on Retain Migration Strategy
Scenario Recognition: • Look for keywords like legacy systems, recent hardware purchase, planned retirement, or compliance restrictions • Questions mentioning applications that are not ready for migration or have unresolved dependencies often point to Retain
Common Exam Scenarios: • A mainframe application with undocumented dependencies - Retain until dependencies are mapped • An application scheduled for decommissioning in 18 months - Retain rather than invest in migration • Systems with strict data sovereignty requirements - Consider Retain or specialized solutions
Differentiation from Other Strategies: • Retain vs Retire: Retain keeps the application running; Retire decommissions it • Retain vs Rehost: Retain keeps it on-premises; Rehost moves it to AWS as-is
Key Points to Remember: • Retain is a temporary decision, not permanent - always reassess • Focus on business justification when explaining why Retain is appropriate • Hybrid connectivity solutions are essential when some workloads are retained • The exam expects you to recognize when migration is not the best immediate choice