Amazon began as a retailer of books, clothing, electronics, etc. In 2006, it launched Amazon Web Services, popularly known as AWS. It has played a key role in ushering in the cloud revolution and helping businesses move their operations to the cloud with ease. Today, it is counted as one of the largest hyper-scale cloud providers, along with other cloud giants such as Microsoft Azure, Google Cloud, and Alibaba.
As of Q4 of 2022, AWS commanded a mighty 32% of the global cloud infrastructure services market.
Source: Global cloud infrastructure market share 2022 | Statista
AWS provides a comprehensive suite of cloud migration tools and services, as well as a flexible and scalable infrastructure that can support businesses of all sizes and domains. In this blog, you will learn about the most prominent AWS cloud migration strategies along with best practices, use cases, and challenges to consider along the way.
Overview of AWS Cloud Migration Strategies
When it comes to AWS migration, there are several migration strategies to choose from. In fact, the strategy will vary depending on specific business needs and objectives. Needless to say, the pros can be maximized and the cons minimized by following the best practices.
The top AWS cloud migration strategies include:
- Rehosting (Lift-and-shift)
- Replatforming (Lift-tinker-and-shift)
- Rearchitecting
- Retaining
- Replacing or Retiring
- Repurchasing
- Relocating
Now let us take a closer look at the key features, benefits, and use cases for each of these strategies.
Rehosting (Lift-and-shift)
Lift-and-shift, also known as rehosting, is a popular migration strategy that involves moving applications and workloads from an on-premises environment to AWS without making any significant changes to the application architecture or code. Under the hood, it is akin to uplifting an application and shifting it as-is to the AWS cloud.
The process of rehosting begins with replicating the existing infrastructure consisting of Virtual Machines (VMs), databases, and networking configurations, in AWS services. The most commonly chosen services include:
- Amazon EC2 (Elastic Compute Cloud) for VMs.
- Amazon RDS (Relational Database Service) for databases.
- Amazon VPC (Virtual Private Cloud) for networking.
Once the duplication process is completed, the applications can be launched in AWS, with their data migrated to AWS cloud storage. Amazon itself offers two major storage services such as Amazon S3 (Simple Storage Service) and Amazon EBS (Elastic Block Store).
The following pros should convince you to consider the best hosting strategy for AWS migration.
Pros of rehosting as an AWS migration strategy:
It is quick and straightforward
Since there is minimal change required to the application architecture or code, rehosting can be considered a quick and straightforward migration strategy. Further, its ease of working implies that it can be implemented within tight timelines and with limited resources.
It possesses minimal risk
Following up on the previous point, no changes to coding help prevent the possibility of bugs creeping in and causing a disruption.
It is proven to be cost-effective
AWS follows pay-as-you-go pricing which means you pay only for the resources you use and also for the period for which they are used. This pricing strategy is cost-effective and also helps forecast the cost for the near future with considerable accuracy.
Cons of rehosting:
It offers limited cloud benefits
Rehosting may not fully leverage the capabilities of AWS, as it does not take advantage of cloud-native services or features that could optimize application performance, scalability, or resilience.
It could result in missed optimization opportunities
Without making changes to the application architecture or code, businesses may not be able to optimize the application for cost savings or take advantage of AWS’s fully managed services, resulting in missed opportunities for operational efficiency and innovation.
It could incur technical debt
Since rehosting focuses on moving the application as-is to the cloud it does not help you clear existing technical debt or inefficiencies in the application’s current status.
Replatforming (Lift-tinker-and-shift)
Replatforming involves making some changes to the application architecture or code to optimize it for the cloud while retaining its core functionality. Unlike rehosting, re-platforming aims to take advantage of cloud-native services and features offered by AWS. Hence, it is considered to improve application performance, scalability, and resilience.
The process of re-platforming begins with a close inspection of the existing application architecture and identifying components that can be replaced with equivalent managed services offered by AWS.
Some such scenarios include:
- Replacing self-managed databases with Amazon RDS
- Replacing custom messaging systems with Amazon Simple Notification Service (SNS)
Once these changes are made, the application is ready for deployment in AWS.
Pros of re-platforming:
It leverages cloud-native capabilities
Since re-platforming involves changing the code to take full advantage of AWS-managed services, it leads to higher levels of scalability, reliability, and performance.
It improves flexibility
Replatforming can provide businesses with the flexibility to adapt their applications to the changing needs of their business as well as leverage new AWS features and services as they become available, enabling faster innovation and agility.
It helps in optimizing cost
By replacing custom components with AWS-managed services, re-platforming can help optimize costs by reducing the need for custom development, maintenance, and support of self-managed services.
Cons of re-platforming:
It is complex
Replatforming requires changes to the application architecture or code which makes the migration process complex, as it introduces the risk of bugs and errors in the new code. This calls for introducing additional steps like quality assurance which increases the duration of the entire migration process.
It involves a steep learning curve
Replatforming may require businesses to learn and adapt to new AWS-managed services. For a technical team that is new to the environment, additional training and resources will be needed to gear them up to understand and use the services effectively.
Re-architecting
Re-architecting also known as refactoring, is an AWS migration strategy that involves making significant changes to the application architecture, design, and code to optimize it for the cloud. The extensive changes required for the application make it expensive and also the heaviest lift of all migration strategies.
The process of refactoring typically involves analyzing the existing application architecture and identifying areas that can be improved for better cloud performance. This may include redesigning components to be more loosely coupled, leveraging microservices architecture, optimizing database schema, or re-architecting monolithic applications into distributed services. Once the necessary changes are made, the application can be deployed in AWS using the updated architecture.
Pros of rearchitecting:
It provides improved scalability and resilience
Refactoring allows businesses to design and build applications that are inherently scalable and resilient, can handle variable workloads, recover from failures, and adapt to changing business needs.
It enhances performance
Refactoring can result in applications that are optimized for the cloud, taking advantage of cloud-native services and features offered by AWS, leading to improved performance and cost optimization.
It assures long-term maintainability.
Re-architecting helps tear down application modules efficiently and rebuild them from scratch. The new versions would be easier to maintain, helping the business achieve operational efficiencies and agility.
Cons of re-architecting:
It is time and resource-intensive
As mentioned earlier, re-architecting is a complex and time-consuming process that requires significant effort and resources to analyze, design, and implement the required changes to the application architecture and code. Also, implementing the changes calls for excessive resources.
It could potentially impact application functionalities
Refactoring may involve making significant changes to the application architecture, design, and code. This can potentially impact the application’s functionality and requires thorough testing and validation to ensure the desired outcomes are achieved.
There is a steep learning curve involved
New application architecture and processes in place mean the business has to train its employees extensively. Even with elaborate training, it could take a significant amount of time for employees to get used to the new architecture. This could result in a slowdown of operations.
Retaining
In AWS migration, you may not always need to move the entire application to a new platform. There could be scenarios when you could keep the existing application infrastructure on-premises while integrating it with the AWS cloud. This helps the business retain its current infrastructure control while leveraging the additional benefits of the cloud.
Retaining typically begins with identifying the core application components that can be moved to the cloud. Amazon S3, Amazon RDS, or AWS Lambda are usually used for this purpose along with other cloud-native services.
Pros of retaining:
- It reduces migration complexity
Since the entire application infrastructure is not required to migrate, it reduces the migration complexity and simplifies integrating only the relevant components.
- It is cost effective
The combined use of existing infrastructure along with new cloud services leads to cost optimization and optimum resource utilization, leading to the minimal need to invest in additional hardware or software.
- It retains control and security
Retaining allows businesses to retain control over their existing infrastructure, ensuring compliance with regulatory and security requirements.
Cons of retaining:
- Limited cloud-native benefits
Retaining allows businesses to leverage only some cloud-native services provided by AWS, limiting the benefits of the cloud such as scalability and resilience.
- Increased complexity
In the long term, as application infrastructure matures and scales, there could be instances of increased maintenance and management overhead.
- Potential vendor lock-in
Since retaining requires the business to be dependent on AWS for its cloud services, it inevitably creates vendor lock-in, wherein switching to a new service provider in the future could be difficult or expensive.
Replacing (Retiring)
Replacing also known as retiring, is an AWS migration strategy that involves completely replacing an existing application with a cloud-native solution, which in this case is AWS. Replacing is typically used when the existing application becomes redundant or outdated and requires significant maintenance to make it suitable for serving business needs.
Since the entire application is being replaced, the first step involves understanding the existing application’s functional requirements and identifying a cloud-native solution that can continue to meet these requirements.
Once the new solution is identified, appraised, deployed, and tested, the existing application is replaced or retired. Finally, all data and functionalities are migrated to AWS while the erstwhile application is sunsetted.
Pros of retiring:
- Makes the infrastructure robust
Retiring an outdated or underperforming application with a modern, cloud-native solution can make the infrastructure robust and capable of meeting future business needs. This could give a significant competitive advantage for the business as well.
- Reduced maintenance costs
Replacing an existing on-premise application with AWS will result in a significant reduction in maintenance costs. This can be attributed to the use of minimal hardware and leveraging of robust cloud services offered by AWS. Also, AWS is proven to be easier to maintain and manage compared to on-premise systems.
Cons of retiring:
- Migration complexity
Replacing requires ripping off the entire system and replacing it with a new one. Needless to say, this requires an extensive amount of planning and resource allocation which is complex and not always affordable for small and medium-scale businesses.
- Disruption to business operations
The interim period during which the old system is being replaced and the new one is being commissioned could result in disruption. This is due to the lack of a significant learning curve for the new solution. However, such instances can be avoided through proactive user training and learning resources.
- Potential data loss
In a worst-case scenario, if planning fails, retiring could potentially result in data loss. This is often the result if data is not properly migrated from the existing application to AWS.
By capitalizing on the retiring strategy in AWS, businesses can retire outdated or underperforming applications with modern, cloud-native solutions, providing increased functionality and performance, reduced maintenance costs, and increased scalability and flexibility.
However, businesses need to carefully consider the potential trade-offs associated with retiring, including migration complexity, disturbance to business operations, and possible data loss, while also considering the benefits of improved functionality and reduced maintenance costs.
Repurchasing
Repurchasing is an AWS migration strategy where a commercial off-the-shelf (COTS) or Software-as-a-Service (SaaS) solution is bought as a replacement for the existing infrastructure. Repurchasing works when the existing application requires significant customization and has become redundant to serve the business requirements.
Pros of repurchasing:
- Reduced development costs
Repurchasing can significantly reduce development costs, as the new solution is typically less expensive than developing a custom solution.
- Improved functionality
Repurchasing can provide businesses with improved functionality and features, as COTS and SaaS solutions are typically more robust and feature-rich than custom solutions.
- Faster time-to-market
Repurchasing can significantly reduce the time-to-market for new solutions, as the solution under consideration is already developed and can be configured and customized quickly.
Cons of repurchasing:
- Limited scope for customization
Purchased software cannot be easily customized. They are often out-of-the-box solutions that are built to serve a generic use case. Hence, repurchased software may not be able to meet all the specific needs of the business.
- Excessive dependency on the vendor
Repurchasing creates an excessive dependency on the vendor since their infrastructure is being utilized for storing and managing data on the cloud. Further, there could also be potential vendor lock-in since you cannot participate in the development process.
Relocating
Relocation, as the term suggests, is basically moving all servers and databases within the cloud to another location without causing any impact or disruption to the current process. For example, moving an RDS instance to another AWS account. During relocation, additional settings such as data encryption, access controls, or similar controls may be implemented.
One of the major advantages of the relocation strategy is that it allows you to move your infrastructure within the cloud without purchasing new hardware, rewriting applications, or modifying existing operations.
Pros of relocating:
- Simplicity and speed
Relocating an application within the AWS environment can be relatively a quick process for a migration strategy. The reason for its simplicity and speed is that it involves moving the entire workload as is, without making significant changes to the application architecture or code. This simplicity can lead to faster migration timelines and also reduces complexity.
- Minimal application changes
The relocation strategy allows for minimal modifications to the application code, as it primarily involves moving the existing workload to a different AWS environment. This can be advantageous when time is a critical factor, as it reduces the need for extensive application refactoring.
- Retaining existing functionality
The relocation strategy aims to maintain the application’s current functionality and behavior during the migration process. This can be beneficial when the primary goal is to replicate the existing application in a different environment without introducing significant changes or disruptions.
Cons of relocating:
- Limited optimization opportunities
The relocation strategy may not take full advantage of the scalability, elasticity, and cost optimization features offered by AWS. By simply moving the application without rethinking its architecture, organizations may miss opportunities for better performance, cost savings, or improved operational efficiency.
- Inability to address technical debt
If the existing application has accumulated technical debt or architectural issues, relocating it without addressing these underlying problems may perpetuate inefficiencies or limitations. This strategy does not provide an opportunity to refactor or optimize the application’s code or architecture.
- Missed cloud-native capabilities
AWS offers several cloud-native services and features that can improve application performance, scalability, and resilience. By solely relocating the application, organizations may miss out on the potential benefits of leveraging these services such as serverless computing, managed databases, or containerization.
- Limited flexibility for future changes
Relocating an application may limit the flexibility to embrace future architectural changes or adopt new technologies and services within AWS. The strategy does not allow room for exploring new possibilities for application modernization or taking advantage of emerging AWS capabilities.
Final Thoughts: Making Your Move to AWS
The AWS migration strategies discussed above can transform your cloud operations and infrastructure. It is worth recalling that no migration strategy is perfect, as each strategy comes with its own set of pros and cons. To ensure that you get your AWS migration done correctly and without any mishaps, follow the below listed best practices and ensure that you are in touch with a reliable cloud partner who will help in:
- Identifying the primary goals for migration.
- Performing a comprehensive analysis of your existing IT infrastructure.
- Selecting the right AWS cloud migration strategy based on your needs and goals.
- Preparing a detailed migration plan and timeline. Further, a backup plan should be ready in case of a mishap.
- Conducting extensive testing before and after the migration to ensure proper functionality and performance.
- Monitoring and optimizing the new infrastructure to ensure that it delivers the required outcomes.
Now you are all set to get started with AWS migration.
If you feel like you want some help to get started, contact our AWS migration experts at services@suyati.com to know more about our AWS Cloud Services!
