Cloud migration is the process of moving data, applications or the overall IT infrastructure of an organisation from local data centres (on-premise) to the cloud, i.e. an environment managed by an external provider. The most well-known and largest providers are Amazon Web Services (AWS), Microsoft Azure, Google Cloud Platform (GCP). Migrating to the cloud allows organizations to enjoy the benefits of cloud computing, such as increased flexibility, reduced infrastructure and IT specialist costs, easy scalability, and ensuring data and applications are available from any location. This process is often part of a broader digital transformation where organisations move to more modern technologies and operating models.
Why migrate to the cloud
The benefits of migrating to the cloud can be very beneficial for organisations of all types and sizes and can help them optimise costs, increase efficiency and competitiveness.
- Increased efficiency: companies are freed from the need to manage their own data centres and can focus more on innovation and business development.
- Cost reduction: reduces the cost of maintenance and purchase of hardware, power and human resources required to run your own servers.
- Scalability and flexibility: cloud environments make it easy and fast to scale up or down capacity to meet your organisation’s current needs.
- Enhanced security: cloud providers invest in robust security measures, ensuring a higher level of data protection.
- Improved accessibility: the cloud allows access to data and applications anywhere, anytime, increasing worker productivity and mobility.
- Fast access to innovation: With the cloud, businesses can quickly implement new technologies and innovations such as artificial intelligence, machine learning or Big Data without having to make extensive changes to their IT infrastructure.
- Data backup and recovery: cloud services often include automatic backup and fast data recovery options, minimising the risk of data loss.
Migration Strategy – 5 “Rs”
The 5 “R” types of cloud migration represent the different strategies that organizations use to move their applications and infrastructure to the cloud. The model was first introduced by Gartner in the early days of cloud computing. The model describes five main approaches to migration: Rehost, Replatform, Refactor, Rebuild and Replace. Each of these approaches varies in terms of complexity, cost, and the degree to which applications are customized for the cloud. Choosing the appropriate strategy depends on the needs of the business, the existing IT infrastructure, and the planned goals.
Rehost (Lift and Shift)
Rehosting means moving existing applications and data to the cloud without any modifications. This approach is also known as “Lift and Shift” because applications are simply “lifted” from their current environment (e.g., a data center) and “moved” to the cloud.
- When to use: Suitable for applications that work well in the existing environment and don’t need major changes. It is the fastest and easiest migration method. This approach is mainly recommended for large and medium sized migrations and enterprises with no cloud experience.
- Benefit: Fast migration with minimal modifications and minimal disruption.
- Cons: Higher operating costs as applications are not optimized for the cloud environment and some native cloud functionality may not be used effectively.
Replatform (Revise)
Replatforming involves making minor changes to the architecture of an application to optimize it for the cloud. This approach can help organizations take advantage of some of the capabilities of the cloud while minimizing the need for significant changes. It is more time consuming and expensive than Rehosting, but still much simpler and less expensive than Refactoring.
- When to use: An appropriate strategy when a business is looking for an efficient way to modernize its applications and take advantage of the cloud without incurring significant costs or risks. Recommended if there is a need to get an on-premise application to a “cloud-ready” state, such as enterprises with legacy applications or small businesses that don’t have the resources to refactor.
- Benefit: Offers a choice of specific features for maximum return on investment.
- Cons: Requires some time and investment for customization, though less than Refactoring. There may be compatibility and application availability issues during migration.
Refactor (Rearchitect)
Refactoring means fundamentally redesigning applications to fully optimize them for cloud operation. It can mean changing the code or modifying the architecture of an application to make it fully cloud or cloud-native. For example, it involves moving from a monolithic architecture to a cloud-based microservices infrastructure.
- When to use: Suitable for applications that need greater flexibility in performance scalability, which can be achieved primarily by moving to the cloud. This approach is also suitable for applications that are not cloud compatible and cannot be moved via Rehost or Replatform.
- Benefit: Increases application efficiency and performance by better optimizing for cloud operation. Enables full use of native cloud features such as high availability, CI/CD automation, automatic recovery or containerization.
- Cons: Requires significant time and investment in application customization.
Rebuild
Rebuilding applications in the cloud involves rebuilding the application architecture from scratch, not migrating from an on-premise environment. It requires designing new application components that use cloud services and modifying the underlying application code to run natively in the cloud.
- When to use: This is a suitable migration strategy for applications that no longer meet business requirements and need to be upgraded. This approach is also suitable for applications that are resource-intensive, need to run in multiple cloud environments, or require high scalability and performance.
- Benefit: Maximize the use of all the features of the cloud solution.
- Cons: Requires significant time and resources, including collaboration with cloud experts, developers and DevOps teams.
Repurchase (Replace)
The last approach involves replacing existing applications with software services provided directly as a cloud solution, rather than migrating them. Typically, this involves replacing existing solutions with a SaaS (Software as a Service) service.
- When to use: there is a more convenient cloud alternative for the application being replaced. Typically this is for applications such as CRM, ERP or other business systems. Also, this approach is ideal for applications that require rework due to changing threats or compliance.
- Benefit: Simplified operations, as the SaaS provider takes care of not only the infrastructure but also all maintenance.
- Cons: There is a need to adapt to the new environment, which may result in the need to adjust internal processes.
Základních pět uvedených strategií ještě lze rozšířit o strategie Retain (uchování těžce migrovatelné aplikace) a Retire (zrušení nepotřebné již nahrazené aplikace).
References
Autorem článku je Experienced Data Analyst Tomáš Veškrna ze společnosti Ness Czech.