AWS › AWS Database Migration Service & Application Migration

What migration strategies, commonly called the six Rs, are used when planning a large scale cloud migration?

Intermediate

Answer

The six common migration strategies include rehosting, which is a straightforward lift and shift of an application with minimal changes, replatforming, which makes small optimizations during the move, repurchasing, which replaces an existing application with a cloud based software as a service alternative, refactoring, which involves redesigning the application to be cloud native, retaining, which means keeping certain systems on premises for now, and retiring, which means decommissioning applications that are no longer needed at all.

// Example planning matrix
// Legacy CRM: repurchase with a SaaS alternative
// Custom internal app: rehost first, refactor later

Real-world example A company migrating dozens of applications decides to simply rehost its stable but low priority internal tools using lift and shift, while committing to a full refactor for its core customer facing application to take advantage of cloud native scalability.

Common follow-ups: How do you decide which of the six Rs is appropriate for a specific application?;Which migration strategy typically delivers the fastest short term cost savings?

AWS Elastic Beanstalk;Well-Architected Framework