The 7R methodology for the migration to AWS is a framework that helps organisations plan and execute a successful migration. The methodology involves assessing each application in your portfolio and categorising it based on its suitability for migration. The seven R’s stand for Retain, Relocate, Rehost, Replatform, Repurchase, Refactor and Retire.
We shall take the example of a hospital infrastructure and show how the various workloads can be treated.
Retain
This involves retaining the application in its current environment and not migrating it to AWS. This may be appropriate for applications that are too costly to migrate or need to remain on premise due to latency constraints.
In the case of the hospital, some applications are used to control Biomedical Instrumentation Technology (CT scanners, pumps, intensive care systems etc.) and need to remain on premises. These applications will be hosted on AWS Outposts to provide uniformity and ease of management (single pane of glass).
Relocate
With the arrival of VMWare Cloud for AWS, VMs can be relocated to AWS without changing anything in the way they are managed.
In the case of the hospital, there was no need to retain VMWare and this option was unused.
Rehost
This involves lifting and shifting an application from its current environment to AWS without any modification. It is the quickest and simplest way to migrate but does not take advantage of AWS services and may not optimise costs.
In the case of the hospital, 314 VM’s (mostly application servers) could be migrated in this manner.
Replatform
This involves making minor changes to the application to take advantage of some AWS services while retaining the core architecture. This approach can provide some benefits of cloud-native services while minimising the risk and effort of a full refactor.
In the case of the hospital, 50 VMs running the backups, file servers, System Center Operations Manager, Security software were replaced by Platform as a Service (PaaS) offerings at AWS. In addition, all VMs used for Citrix could be replaced by Desktop as a Service AWS offerings.
Repurchase
This involves replacing the existing application with a cloud-native software as a service (SaaS) application. It can reduce the operational overhead of managing the application and provide more agility but may require changes to business processes.
At the hospital, 29 VMs running applications could be replaced by alternatives that were offered as SaaS solutions.
Refactor
This involves rebuilding an application from scratch using modern cloud-native architecture patterns or moving to a cloud native solution provided by AWS.. It can provide the most benefits but is the most time-consuming and requires significant investment.
The hospital decided that the traditional SQL server based data warehouse would be moved to a cloud native AWS data lake with corresponding serverless services such as Amazon Glue, Amazon Athena and Amazon Quicksight.
Retire
This involves retiring applications that are no longer needed or have low business value. It can reduce the complexity of the migration and ongoing management costs.
The hospital identified 128 VMs that did not need to be migrated and could be retired.
Cambrian uses the 7R methodology to help organisations prioritise which applications to migrate first, determine the appropriate migration strategy, and manage the risks associated with migration. We carefully evaluate each application in your portfolio and choose the migration strategy that best meets your business needs.
is helping customers re-architect their IT through the introduction of cloud services. Combining 20 years of experience as a CTO with interchanged periods of responsibility for IT operations, he matches business requirements with cloud technologies in innovative ways.
