Cloud Migration Strategies for Cloud Architects

Introduction

As organizations increasingly move their workloads to the cloud, understanding the various strategies for cloud migration is crucial for cloud architects. These strategies help in planning and executing a successful migration that aligns with business goals, minimizes disruption, and leverages cloud benefits. In this blog post, we'll explore the primary cloud migration strategies, often referred to as the "6 R's" of cloud migration, and how they are defined by leading industry sources like Gartner, AWS, Microsoft Azure, and Google Cloud.

1. Rehost (Lift and Shift)

Description: Rehosting involves moving applications directly from the existing environment to the cloud with minimal changes. This strategy is often called "lift and shift."

Advantages: Quick migration, lower upfront cost, minimal disruption.

Use Cases: Suitable for applications that are critical and need to be moved quickly without any changes.

2. Replatform (Lift, Tinker, and Shift)

Description: Replatforming involves making a few optimizations to take advantage of cloud benefits without changing the core architecture.

Advantages: Improved performance, takes advantage of cloud services, relatively quick.

Use Cases: When minor optimizations can lead to significant cost savings or performance improvements.

3. Refactor (Re-architect)

Description: Refactoring, or re-architecting, involves redesigning the application to be cloud-native, fully leveraging cloud capabilities.

Advantages: Maximizes cloud benefits such as scalability, performance, and cost-efficiency.

Use Cases: For applications that need significant changes to meet business goals or performance requirements.

4. Repurchase (Replace)

Description: Repurchasing involves moving to a different product, typically by replacing the existing application with a SaaS solution.

Advantages: Reduced management overhead, modern features, cost efficiency.

Use Cases: When current applications are outdated or not cloud-compatible, and a SaaS alternative is available.

5. Retire

Description: Retiring involves identifying and turning off applications that are no longer useful.

Advantages: Cost savings, reduced complexity.

Use Cases: When applications are redundant or have been replaced by other solutions.

6. Retain (Revisit)

Description: Retaining involves keeping some applications on-premises or in a hybrid setup for various reasons such as compliance, security, or dependency issues.

Advantages: Flexibility, maintaining control over certain applications.

Use Cases: For applications that are not ready for migration or need to stay on-premises.

Terminology Used by Leading Industry Sources

Gartner

Gartner has extensively documented cloud migration strategies using the "6 R's" terminology:

• Rehost
• Replatform
• Refactor
• Repurchase
• Retire
• Retain

AWS (Amazon Web Services)

AWS uses the same "6 R's" framework:

• Rehost (Lift and Shift)
• Replatform (Lift, Tinker, and Shift)
• Repurchase (Move to a different product)
• Refactor/Re-architect (Re-imagine)
• Retire (Decommission)
• Retain (Revisit)

Microsoft Azure

Azure’s cloud adoption framework discusses migration strategies with slightly different terms but similar concepts:

• Rehost
• Refactor
• Rearchitect
• Rebuild (Similar to Refactor)
• Replace (Repurchase)
• Retain

Google Cloud (GCP)

Google Cloud aligns closely with these strategies:

• Rehost
• Replatform
• Refactor
• Repurchase
• Retire
• Retain

Conclusion

Understanding and selecting the right cloud migration strategy is essential for cloud architects. Whether it's rehosting for a quick lift and shift or refactoring for a cloud-native transformation, each strategy offers unique benefits and use cases. By aligning these strategies with industry standards and guidelines from Gartner, AWS, Azure, and GCP, organizations can ensure a smooth and successful cloud migration.