Amazon Web Services provides cloud computing services to create effective, automated, scalable, dynamic computing environments. However, the migration to AWS is a non-trivial endeavor. Whether your company is considering this possibility in order to reduce costs, increase resource utilization, profit from new infrastructure capacities, or any other benefit you can think of, having a deep understanding of the model will help you decide which R to select for your applications.
Amazon describes a “6 Rs” model, which describes ways to achieve a successful migration to AWS.
This model suggests moving apps from the on-premise environment to the cloud without any modification, using tools such as Server Migration Service (SMS) or manual procedures. It is the most commonly used strategy, and it is suitable for massive legacy migrations and companies with a shortage of cloud technology skills.
This strategy describes moving apps almost as-is but replacing some components to make use of cloud services. Even though the migration is relatively swift, it has a restricted ability to leverage the advantages of the cloud.
This model requires substituting the application entirely with a cloud service. Effectively, this is a licensing change: rather than using a traditional on-premise license; your company starts using the same application but as a cloud service. For instance, ending a license agreement for an on-premise orchestration platform and beginning to use the same system as a service on the AWS Marketplace.
Refactor / Re-architect
This strategy calls for a total overhaul of the app to rebuild it for a cloud-native environment. It is a proper option for projects where there is an existing business need to boost performance, add scale, or include features that would not be possible on-premises, providing maximum efficiency and flexibility. In several circumstances, refactoring / re-architect means breaking up the app into autonomous services and moving to a microservices architecture.
The final two strategies are “passive” as they do not involve migrating an application to the cloud.
This strategy consists of recognizing apps that are not helpful and can be turned off rather than migrated to the cloud. This can free up resources for apps that are useful and can benefit from the cloud.
Some apps may not be suitable or may not be ready for migration to the cloud yet. It is possible to keep them on-premise, permanently or at least during the initial stages of the migration project.