Migration Statergies

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

1. Business Goals: How critical is speed, cost, or scalability?

2. Technical Feasibility: Can the application be modernized or must it remain as-is?

3. Time and Resource Constraints: How much time and resources are available for migration?

4. 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.