参考回答
Well, there are so many migration strategies to consider when moving applications to the cloud such as Retire, Retain, Rehost, Relocate, Repurchase, Replatform, Refactor or re-architect, and so on.
- Retire – If you think there is no business value in retaining the app or eliminating the cost of maintenance, reducing security risks, then you can decommission or archive.
- Retain – Retain should be considered when you want to maintain security and compliance, a detailed assessment, dependencies, no business value, the app requires careful assessment and planning, and above all keep zombie or idle applications in your source environment.
- Rehost – This is a lift and shift strategy. It is possible to migrate machines literally. You no longer have to worry about source platforms, physical, virtual, or another cloud, anything is possible to migrate to AWS. Also, here you don't have to worry about compatibility. Apart from that,
- Performance disruption
- Long cutover windows
- Long-distance data replications
- Relocate – As the name implies, transferring a large number of servers to a different virtual private cloud (VPC), AWS Region, or AWS account is possible. Relocate is possible to transfer an Amazon Relational Database Service (Amazon RDS) DB instance to another VPC or AWS account. And here you are not required to purchase new hardware, rewrite applications, or modify existing operations.
- Repurchase – This strategy is drop and shop, choose an app that offers more business value than the on-premises one where you don't have to maintain a specific infrastructure or you can pay-as-you-go pricing models. So here you have two options
- Move from traditional licence to SaaS
- Version upgrades or third-party equivalents
- Replace a custom application
- Replatform – This one means to lift, tinker, and shift or lift and reshape. Choose this strategy when you need to introduce some level of optimization in order to operate the application efficiently, reduce costs, or take advantage of cloud capabilities. For example, platform a Microsoft SQL Server database to Amazon RDS for SQL Server.
- Refactor – Here the architecture can be modified with the assistance of cloud-native features to enhance agility, performance, and scalability.