As organisations embrace cloud computing, it’s important to understand the different strategies for moving applications and data to the cloud. The “7 R’s” of cloud migration offer a clear framework to help businesses navigate this process. Originally introduced by Gartner in 2010 as the “5 R’s,” this model was later expanded by AWS to better categorise applications based on their readiness for cloud migration.
The 7 R’s of Cloud Migration
The 7 R’s of cloud migration, as developed by Amazon Web Services, listed according to level of effort, include:
- Retire (Least effort)
- Retain
- Relocate
- Rehost
- Repurchase
- Replatform
- Refactor (Most effort)
These strategies are designed to help organisations assess their applications and determine the most effective migration path, based on their unique circumstances.
When to Use Each Migration Model
Choosing the right migration strategy depends on various factors, including business objectives, application architecture and technical requirements.
When to use each of the 7 R’s:
- Retire: Useful for streamlining the application portfolio by eliminating non-essential applications.
- Retain: Necessary for applications that must remain on-premises due to compliance, security, or technical constraints.
- Relocate: Ideal for virtualised environments where minimal disruption is essential, and existing investments need to be preserved.
- Rehost: Best for organisations looking for a quick migration with minimal changes, especially when legacy systems are involved.
- Repurchase: Appropriate for applications that can transition to SaaS solutions, providing better features and management.
- Replatform: Suitable for applications that can benefit from cloud optimisations without extensive modifications.
- Refactor: Recommended for applications that require significant enhancements in performance or scalability and where long-term benefits justify the investment.
The 7 R’s in detail
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Retire
The retire strategy involves identifying applications that are no longer useful or necessary and decommissioning them. This step is crucial for optimising resources and reducing costs. Many organisations find that they have legacy applications that no longer serve a purpose or are redundant due to newer software implementations.
Benefits:
- Cost Savings: By retiring outdated or underperforming applications, organisations can significantly reduce operational costs. This can free up resources that can be redirected toward more critical initiatives.
- Resource Optimisation: This strategy allows teams to focus on more critical applications and services, improving overall productivity and effectiveness.
- Simplified Management: Reducing the number of applications can streamline management processes, leading to improved operational efficiency. Fewer applications mean less complexity in terms of updates, security, and compliance.
Considerations:
Organisations must conduct a thorough analysis to ensure that retiring an application will not negatively impact business operations or compliance requirements. It is essential to engage stakeholders to manage expectations and ensure that any critical dependencies are addressed before decommissioning applications.
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Retain
The retain strategy involves keeping certain applications on-premises due to various factors such as compliance, performance, or strategic importance. This strategy recognises that not all workloads are suitable for the cloud, and some applications may be better off remaining in a traditional environment.
Benefits:
- Control and Compliance: Organisations can maintain control over critical systems and ensure compliance with regulatory requirements. This is particularly important for industries that are heavily regulated, such as finance and healthcare.
- Risk Mitigation: By retaining certain applications, organisations can mitigate risks associated with migration, such as data loss or service disruption. This is especially relevant for mission-critical applications that require high availability and reliability.
- Performance Optimisation: Some applications may perform better in an on-premises environment due to specific hardware or network configurations. Organisations can optimise performance by retaining these applications where they can be best supported.
Considerations:
Deciding which applications to retain requires careful assessment and a clear understanding of business priorities and constraints. Organisations should have a plan for how to manage and support these retained applications moving forward, including considerations for maintenance, upgrades, and security.
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Relocate
Relocating involves migrating workloads from one environment to another with minimal changes, often focusing on virtualized environments. This strategy is particularly useful for applications running on platforms like Docker or Kubernetes. The goal is to move workloads to the cloud while maintaining their existing configurations and management processes.
Benefits:
- Minimised Downtime: Relocation allows for seamless migration with minimal disruption to ongoing operations. This is critical for organisations that require high availability and cannot afford significant downtime during migration.
- Cost Predictability: By maintaining existing configurations, organisations can better predict migration costs. This predictability can help in budgeting and financial planning, making it easier to allocate resources effectively.
- Easier Management: Organisations can continue using familiar tools and processes during the migration. This familiarity can reduce the learning curve for IT staff and minimise the risk of errors during the transition.
Considerations:
This approach may not address deeper performance issues inherent in the application design, necessitating further optimisation post-migration. Organisations should also consider the long-term implications of staying with legacy systems, as this could hinder future innovation and scalability.
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Rehost (Lift-and-Shift)
Rehosting, commonly referred to as “lift-and-shift,” involves moving applications to the cloud with minimal changes. This strategy allows organisations to transfer their existing applications and data directly to a cloud environment without altering the underlying architecture. Rehosting is often the first step for organisations looking to migrate to the cloud quickly.
Benefits:
- Speed: Rehosting is typically faster than other strategies, allowing organisations to quickly realise the benefits of cloud computing. This rapid migration can help organisations respond to market demands more effectively.
- Simplicity: The process is straightforward, making it ideal for organisations lacking in-house cloud expertise. This simplicity can reduce the burden on IT teams and allow them to focus on other critical tasks.
- Immediate Cost Savings: Organisations can reduce infrastructure costs by leveraging cloud resources without significant upfront investment in new technologies. This can lead to improved cash flow and financial flexibility.
Considerations:
While rehosting facilitates a rapid migration, it may not fully exploit cloud-native features, potentially leading to missed opportunities for optimisation and cost savings in the long run. Additionally, applications may not perform optimally in the cloud environment without necessary adjustments, which could affect user experience and satisfaction.
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Repurchase
Repurchasing involves moving from a perpetual licensing model to a Software-as-a-Service (SaaS) model. This strategy is suitable for organisations that can easily transition to newer versions of their applications. By adopting SaaS solutions, organisations can benefit from the latest features and updates without the burden of managing infrastructure.
Benefits:
- Access to New Features: Organisations can benefit from the latest features and updates without the burden of managing infrastructure. This access can enhance functionality and improve overall performance.
- Reduced Maintenance: By adopting SaaS solutions, organisations can offload maintenance responsibilities to the service provider. This reduction in maintenance can free up IT resources for more strategic initiatives.
- Scalability: SaaS solutions often come with built-in scalability, allowing organisations to grow without significant investments in new infrastructure. This flexibility can be crucial for organisations experiencing rapid growth or seasonal fluctuations in demand.
Considerations:
This approach may require a cultural shift within the organisation, as teams adapt to using third-party services rather than managing applications in-house. Organisations must also evaluate the security and compliance implications of using SaaS solutions, ensuring that they meet industry standards and regulations.
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Replatform
Replatforming entails making a few optimisations to the application to take advantage of cloud capabilities while retaining the core architecture. This might involve using managed services or cloud-native features to enhance performance. Replatforming strikes a balance between the simplicity of rehosting and the complexity of refactoring.
Benefits:
- Improved Performance: By leveraging cloud services, organisations can achieve better performance without a complete overhaul of the application. This improvement can lead to enhanced user experiences and increased productivity.
- Cost Efficiency: Organisations can reduce operational costs by utilising managed services, such as databases or load balancers. This cost efficiency can contribute to overall financial health and sustainability.
- Faster Time-to-Market: Minor adjustments can lead to quicker deployment of new features and services. This agility can help organisations stay competitive in rapidly changing markets.
Considerations:
Replatforming requires a careful assessment of which optimisations will yield the most significant benefits without extensive redevelopment. Organisations should also ensure that their teams have the necessary skills to implement these changes effectively, as a lack of expertise can hinder the success of the migration.
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Refactor (Re-architect)
Refactoring involves reimagining how an application is built and developed, often incorporating cloud-native features such as microservices, serverless architecture, and dynamic scaling. This strategy is typically driven by a business need to enhance scalability or performance. Refactoring is the most complex of the 7 R’s and often requires significant investment in time and resources.
Benefits:
- Full Utilisation of Cloud Features: Refactoring enables organisations to leverage the full capabilities of the cloud, leading to improved scalability and resilience. This utilisation can enhance overall performance and user satisfaction.
- Long-term Cost Savings: Although this approach may require significant upfront investment, it can result in substantial long-term savings and operational efficiency. Organisations can benefit from reduced maintenance costs and improved resource allocation.
- Enhanced Agility: Organisations can respond more quickly to changing market demands and customer needs. This agility can be a significant competitive advantage in today’s fast-paced business environment.
Considerations:
Refactoring can be complex and time-consuming, requiring a deep understanding of cloud technologies and potentially significant redevelopment efforts. Organisations must also consider the potential risks associated with major changes to critical systems, including the possibility of service disruptions and data loss.
Real-Life Examples of the 7 R’s in Action
Several organisations have successfully implemented cloud migration strategies using the “7 R’s” framework.
Here are some notable examples:
1. Netflix: Rehost (Lift-and-Shift)
Netflix migrated its massive infrastructure from on-premises data centres to Amazon Web Services (AWS) using the rehost strategy. This approach allowed them to scale quickly, improve reliability, and reduce operational costs significantly. By lifting and shifting their applications, Netflix could focus on enhancing their streaming service without the burden of managing physical servers.
2. Airbnb: Refactor
Airbnb utilised the refactor strategy to modernise its infrastructure and embrace a microservices architecture. This approach allowed them to improve scalability, enhance performance, and introduce new features more quickly, ultimately providing a better user experience for their customers.
3. Walmart: Retain
In 2017, Walmart migrated to Microsoft Azure, significantly reducing operational costs by more than 60% and increasing performance speeds by ten times. While they migrated many applications, they also retained certain critical systems on-premises to maintain control and comply with regulatory requirements.
Actionable Steps for Organisations
- Assess Current Applications: Conduct a thorough inventory of all applications and workloads to understand their importance, performance, and costs. This assessment should include evaluating the technical architecture, dependencies, and usage patterns of each application.
- Engage Stakeholders: Involve key stakeholders from different departments to gather insights and ensure alignment on migration goals. Engaging stakeholders can help identify critical applications and prioritise them for migration.
- Define Objectives: Clearly outline the objectives of the migration, whether it’s cost reduction, improved performance, or enhanced scalability. Establishing clear objectives will guide decision-making throughout the migration process.
- Choose the Right Strategy: Based on the assessment, select the most appropriate migration strategy from the 7 R’s for each application. Consider the unique requirements and constraints of each application when making this decision.
- Plan the Migration: Develop a detailed migration plan that includes timelines, resources, and risk mitigation strategies. A well-defined plan will help ensure a smooth transition and minimise disruptions to business operations.
- Monitor and Optimise: After migration, continuously monitor application performance and costs, and optimise as necessary to fully leverage cloud capabilities. Regular monitoring can help identify areas for improvement and ensure that applications are performing optimally in the cloud environment.
Conclusion
The 7 R’s of cloud migration offer a clear framework for organisations moving to the cloud. By understanding the pros and cons of each approach, businesses can make decisions that fit their goals and technical needs. As cloud adoption grows, using these strategies is key to gaining the full benefits of cloud computing and ensuring a smooth migration.
In short, choosing the right migration strategy helps ensure a successful cloud transition, driving innovation and boosting operational efficiency.
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