AWS Follows 6 R's of Migration steps , The 6 R's of AWS Migration Strategies provide a structured approach to migrate applications to the cloud. Each strategy addresses a specific use case or scenario based on business and technical needs.
Rehosting (Lift-and-Shift)
Description: Moving applications to the cloud with minimal or no modifications.
Key Features:
Typically involves migrating workloads as-is.
Useful when rapid migration is needed or when legacy applications are not cloud-optimized.
Use Cases:
Applications with no immediate need for redesign.
Scenarios requiring quick migration to meet deadlines.
Tools: AWS Migration Hub, AWS Application Migration Service (MGN).
Replatforming (Lift, Tinker, and Shift)
Description: Making minimal changes to applications during migration to optimize performance or cost in the cloud.
Key Features:
Minor adjustments like upgrading to a managed database service (e.g., moving from MySQL on-premises to Amazon RDS).
Balances speed of migration with some level of optimization.
Use Cases:
Applications needing slight improvements without a full rearchitecture.
Reducing management overhead (e.g., moving to managed services).
Examples: Replacing self-hosted databases with AWS-managed solutions.
Retire
Description: Decommissioning or phasing out unused or redundant applications.
Key Features:
Reduces costs by eliminating unnecessary workloads.
Identifies applications that no longer serve business objectives.
Use Cases:
Legacy systems with no future requirements.
Consolidation of functions into fewer systems.
Tools: Cost analysis and dependency mapping tools.
Retain (Keep as-is)
Description: Keeping certain applications in their current environment (on-premises or legacy systems).
Key Features:
Applies to systems that cannot or should not be migrated (e.g., due to latency, compliance, or dependency reasons).
These applications may still integrate with cloud workloads.
Use Cases:
Applications reliant on specialized hardware.
Systems needing long-term on-premises presence due to compliance or latency.
Examples: Retaining ERP systems or industrial control systems.
Repurchasing
Description: Replacing existing applications with new cloud-native solutions, often using SaaS.
Key Features:
Typically involves abandoning legacy applications and adopting modern equivalents.
Shifts from license-based software to subscription-based SaaS.
Use Cases:
Outdated or costly legacy systems.
Adopting cloud-native solutions for improved functionality or cost efficiency.
Examples: Moving from a self-hosted CRM to Salesforce.
Refactoring (Re-architecting)
Description: Reimagining and re-engineering applications to leverage cloud-native features.
Key Features:
Significant changes to application code and architecture.
Unlocks advanced cloud benefits like serverless computing, microservices, and scalability.
Use Cases:
Applications needing enhanced scalability, agility, or performance.
Legacy systems hindering business innovation.
Examples: Breaking monolithic applications into microservices using AWS Lambda or Amazon ECS.
Strategy Selection Criteria
Business Goals: How critical is speed, cost, or scalability?
Technical Feasibility: Can the application be modernized or must it remain as-is?
Time and Resource Constraints: How much time and resources are available for migration?
Compliance Requirements: Are there regulatory constraints on where data or applications can reside?
The 6 R's provide a flexible framework to tailor migration strategies to meet diverse business and technical needs.