[12:01] Peace Popoola The 7Rs migration strategy (based on AWS documentation)

The 7 Rs of Cloud Migration: Explained.

5 min read

Cloud migration involves transferring applications, data, and other business elements from an on-premises infrastructure to a cloud-based environment. The “7 Rs” framework is commonly used to guide this migration process. Each of the 7 Rs represents a different strategy for migrating workloads to the cloud, tailored to the specific needs and characteristics of the applications being moved. The strategies include Rehost, Replatform, Repurchase, Refactor, Retire, Retain, and Relocate.

1. Rehost

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Rehosting, also known as “lift and shift,” involves moving applications to the cloud with minimal changes. This strategy is often chosen for its speed and simplicity. By rehosting, organizations can quickly gain the benefits of cloud infrastructure, such as scalability and flexibility, without significant alterations to their existing applications. 

Example: A company with a large number of virtual machines running a web application decides to rehost these VMs on a cloud platform like AWS EC2 or Azure Virtual Machines. This approach allows the company to take advantage of cloud scalability and flexibility without modifying the application. While rehosting is efficient in the short term, it may not fully leverage the capabilities of the cloud environment, potentially leading to higher operational costs over time.

2. Replatform
Replatforming, or “lift, tinker, and shift,” involves making slight optimizations to applications during the migration process. These adjustments are made to take advantage of certain cloud features without a complete overhaul of the application’s architecture. Replatforming can improve performance and scalability while requiring moderate effort and investment. It offers a balance between the simplicity of rehosting and the extensive benefits of a fully cloud-native application.

Example: A company decides to migrate its e-commerce application to the cloud. During the migration, they switch from a self-managed MySQL database to Amazon RDS (a managed database service) to reduce operational overhead and improve reliability. Replatforming can improve performance and scalability while requiring moderate effort and investment, offering a balance between the simplicity of rehosting and the extensive benefits of a fully cloud-native application.

3. Repurchase
Repurchasing involves moving to a different product, typically a cloud-based Software as a Service (SaaS) solution. This strategy is suitable for organizations looking to replace their current applications with modern, fully managed alternatives. By adopting SaaS solutions, businesses can benefit from reduced maintenance, automatic updates, and improved efficiency. However, this approach may involve challenges related to data migration, integration, and potential loss of customization.

Example: A company using an on-premises customer relationship management (CRM) system decides to switch to Salesforce, a cloud-based CRM. This eliminates the need for maintaining hardware and software while providing enhanced features and integrations. Repurchasing may involve challenges related to data migration, integration, and potential loss of customization, but it offers access to modern, fully managed applications.

4. Refactor

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Refactoring, or re-architecting, entails rethinking and rewriting applications to better align with the cloud environment. This strategy often involves breaking down monolithic applications into microservices and fully utilizing cloud-native features such as auto-scaling, serverless computing, and managed databases. While refactoring demands significant investment in time and resources, it can result in substantial long-term benefits, including enhanced performance, cost efficiency, and agility.

Example: A financial services company has a monolithic application for processing transactions. By refactoring, they decompose the application into microservices using AWS Lambda for serverless execution and Amazon DynamoDB for a scalable NoSQL database. While refactoring demands significant investment in time and resources, it can result in substantial long-term benefits, including enhanced performance, cost efficiency, and agility.

5. Retire
Retiring involves identifying and decommissioning applications that are no longer useful or relevant. This strategy helps organizations streamline their application portfolio, reduce costs, and focus on maintaining and enhancing more critical applications. Properly assessing which applications to retire ensures that resources are not wasted on maintaining outdated or redundant software, contributing to a more efficient IT landscape.

Example: An organization reviews its application portfolio and finds that an old internal reporting tool is rarely used and redundant due to newer analytics platforms. They decide to retire this tool. Properly assessing which applications to retire ensures that resources are not wasted on maintaining outdated or redundant software, contributing to a more efficient IT landscape.

6. Retain

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Retaining, or “revisit,” means keeping certain applications on-premises, usually because they are not ready for cloud migration or due to regulatory, compliance, or latency concerns. This strategy allows organizations to maintain control over sensitive data and critical applications while continuing to evaluate and plan for future cloud migration. Retaining applications may be necessary for ensuring stability and compliance, even if it means missing out on some of the immediate benefits of cloud infrastructure.

Example: A healthcare provider decides to retain its patient management system on-premises due to strict data privacy regulations and latency requirements, while other less sensitive applications are migrated to the cloud. Retaining applications may be necessary for ensuring stability and compliance, even if it means missing out on some of the immediate benefits of cloud infrastructure.

7. Relocate
Relocating involves moving entire data centers to the cloud without making significant changes to the applications themselves. This strategy is often used when organizations need to exit their data centers quickly and migrate their existing virtual machines (VMs) to a cloud provider. Relocating offers a straightforward and rapid migration path, allowing businesses to leverage cloud infrastructure for operational efficiency while maintaining their existing applications largely unchanged.

Example: A large enterprise with multiple data centers decides to relocate its infrastructure to the cloud to avoid the cost and complexity of maintaining physical data centers. They use a lift-and-shift approach to migrate their VMs to a cloud platform like Google Cloud. Relocating offers a straightforward and rapid migration path, allowing businesses to leverage cloud infrastructure for operational efficiency while maintaining their existing applications largely unchanged.

The 7 Rs of cloud migration provide a structured approach to transitioning to the cloud, offering various strategies to suit different business needs and application characteristics. By carefully selecting and implementing the appropriate migration strategy, organizations can achieve a smooth transition to the cloud, optimize their IT infrastructure, and maximize the benefits of cloud computing. Whether aiming for quick migration with minimal changes or pursuing a comprehensive overhaul to fully embrace cloud-native features, the 7 Rs framework helps guide decision-making and strategic planning throughout the migration process.