Rehosting vs Replatforming: Choosing the Best Cloud Migration Strategy

Alina Svidunovich

Content Writer, Ispirer Systems

According to research, organizations spend up to 29% of their resources on maintaining legacy applications and systems. The good news is that this can be easily fixed if you choose the right strategy and migrate legacy systems.

But which strategy should you choose? What are their advantages and disadvantages? This is exactly what we will talk about in this article.

Migration strategies to choose

There are different approaches to migration:

• Rehosting is migrating an application to the cloud without implementing changes to utilize cloud features
• Replatforming is a cloud migration strategy where an application is moved from a legacy platform to the cloud with few changes to the codebase
• Refactoring usually involves rewriting or rearchitecting an app to enhance performance or scalability
• Replacing is shifting infrastructure to the cloud without the need for new hardware, application rewrites, or adjustments to current operations
• Retaining involves keeping the applications in the same environment. It can include applications that require refactoring, which can be deferred for a future time
• Retiring means decommissioning the entire system or processes to optimize the migration of the other applications

What is rehosting?

Rehosting is the most straightforward and fastest method of cloud migration. Existing applications have just been lifted and shifted from on-premises to the cloud. This method doesn’t involve major challenges. Note that rehosting applications in their original form might limit the potential for cost optimization and scalability improvements in the long run.

The benefits of rehosting

Rehosting boasts several benefits:

• Quick migration. Rehosting makes it possible to migrate quickly without making complex code modifications.
• Scalability. Migrating to the cloud offers perfect scalability, which allows your apps to adjust resources more effectively based on demand. It greatly optimizes costs.
• Reduced risks. Preserving the initial architecture helps to avoid additional bugs or downtime during migration.
• Lower upfront costs. Rehosting doesn't require rearchitecting and recoding, so it generally involves less engineering effort.

The drawbacks of rehosting

The primary cons of rehosting include the following:

• Limited optimization. Being rehosted, applications are not optimized to take advantage of cloud-native features which means that performance, scalability and cost-efficiency gains can be missed.
• Technical debt. Rehosting relocates existing challenges—inefficient code, legacy dependencies, and architectural issues still exist in the new environment.
• Temporary solution. Rehosting is often seen as a first step rather than a long-term strategy. Further modernization is usually necessary down the road.

Rehosting: Best practices

Is rehosting your choice? This is what you need to keep in mind:

• Proper assessment. Start with a detailed evaluation of your system and create a thorough migration plan.
• Choose the right provider. A cloud provider should meet your needs in terms of performance, security, and scalability.
• Migrate data. Determine the right approach for migrating your data, considering volume, latency, and compliance.
• Test and validate. Thoroughly test your applications to ensure they work as expected.
• Monitor and optimize. Monitoring solutions are useful for tracking performance, availability, and costs.
• Security and compliance. Protect data with proper security measures and comply with regulations.

Replatforming: What is it?

Replatforming, also known as “lift, tinker, and shift,” is a cloud migration strategy in which applications are moved from the legacy environment to the new platform with few adjustments to the codebase to improve performance and scalability. This keeps your core functions intact while the application is adapted to the new cloud environment.

Replatforming: Benefits

Here are some key benefits of using replatforming as a cloud migration strategy:

• Performance boost. Replatforming usually involves optimizing your applications for cloud-native features. This leads to faster response times and increased efficiency.
• Reduced technical debt. By addressing underlying technical issues, re-platforming allows developers to update outdated components and make an application more stable and easy to maintain.
• Foundation for future modernization. Replatforming sets the foundation for deeper modernization (like microservices or serverless) without the all-or-nothing approach with refactoring.

Replatforming: Cons

• Compatibility issues. Modifying certain parts of the application may cause unexpected issues with legacy systems or custom integrations. What is more, migrating after replatforming may cause your legacy applications to encounter compatibility challenges due to dependencies on specific hardware or software versions that aren’t easily transferable to the cloud.
• Potential for downtime. Changing core components—like migrating from a self-hosted database to a managed one—can result in service interruptions, especially if dependencies aren’t properly accounted for. Even small changes can cause user-facing issues or data inconsistencies without a strong migration and rollback plan.
• Security concerns. Replatforming can lead to security concerns, which require careful consideration and integration with the cloud environment to ensure proper protection.

Replatforming: Best practices

Would replatforming be your approach to cloud migration? Here are the best practices for replatforming:

1. Assess and prioritize workloads. Not every application is a good choice for rehosting. Start with identifying low-complexity and high-impact workloads. Avoid migrating apps with deep on-premise dependencies unless necessary.
2. Choose a reliable platform. Choose a reliable, scalable, and robust platform from a reputable vendor.
3. Plan your project. Your migration project should follow a plan to help you follow the deadlines and track progression.
4. Migrate data. Data migration is a critical process. Data loss or corruption can cause serious reputational damage. You should definitely choose a migration tool or service that you can trust, such as SQLWays.
5. Optimize architecture. If you are moving to the cloud, then it is worth modifying your application architecture to maximize cloud-native features. This can perhaps involve microservices architecture.
6. Test. Before going live, your application must be tested. Identify and fix any issues to ensure the new platform meets your needs and provides a smooth user experience.
7. Train and upskill teams. Train your personnel on using the new platform and provide ongoing support to avoid confusion.

Final thoughts

We hope the differences between the two approaches are clear and that you can easily determine which method is right for you. If you need help migrating your applications, contact the experts at Ispirer. Our automated migration products will help speed up your migration project and save time during the migration. Book a call with our experts, or try SQLWays for free.