Refactoring Applications for Cloud Migration: What, When and How

This article was written by Gaurav Mishra, Director, Technology at Material

Enterprises migrating their applications to the cloud often face the challenge of confirming an approach that is in line with their overall migration goals. Before deciding on an application migration approach, consider a few key questions:

• What are your business goals?

• What are your application capacities?

• What is the estimated cost for your cloud migration process?

The answers to these questions will help set the foundation for a successful cloud migration and ensure your approach is aligned with your overall goals and needs.

One of the most popular methods of cloud migration is refactoring. What is it, and when should organizations choose it as their migration approach?

What is Refactoring?

Refactoring is the process of running your applications on the infrastructure of a cloud provider, which requires the complete re-architecting of your applications to better suit the new cloud environment. This approach involves modifying existing applications, or a large chunk of the codebase, to take better advantage of cloud-based features and the extra flexibility they offer.

Refactoring migration is often more complex than other cloud migration approaches. This is because, in addition to making application code changes, you must ensure these changes do not impact the external behavior of the application.

For example, if your existing application is resource intensive, it may cause higher cloud billing because it involves big data processing or image rendering. In that case, redesigning the application for better resource utilization is required before moving to the cloud.

While refactoring is among the most time- and resource-intensive of all migration approaches, it can result in the lowest monthly spend once migration is complete. Let’s explore some key benefits and limitations of this approach.

Benefits of Refactoring

• Long-term cost reduction. Refactoring ensures an over-time reduction in costs, matching resource consumption with demand and eliminating waste. This results in a better and more lasting cloud ROI compared to other approaches.

• Increased resilience. By decoupling the application components and wiring together highly available and managed services, the application inherits the resilience of the cloud.

• Responsive to business needs. Using this approach enables the applications to leverage the auto-scaling features of cloud services that scale up and down according to demand.

Limitations of Refactoring

• Vendor lock-in. The more cloud-native your application is, the more tightly it is coupled to your current cloud provider.

• High degree of skill required. As a complex process, refactoring requires the highest level of application, automation and cloud skills and experience.

• Time-intensive. Because refactoring is resource-intensive and complicated – since it involves changing a non-cloud application to a cloud-native application – it can take a significant amount of time to complete.

• Potential for costly errors. Refactoring involves changing everything about an application, so there are ample opportunities for errors to creep into the process. Each mistake can cause delays, cost escalations and potential outages.

When to choose refactoring?

Having considered the advantages and limitations associated with refactoring, the next step is to determine if and when to choose this approach for your migration needs. The following considerations can inform your choice.

• Efficiency is a priority. Refactoring holds the potential to be the most efficient cloud migration model, since cloud-native applications leverage continuous cloud innovation to drive cost reductions and enhancements in operations, resilience, resposiveness and security.

• Tapping the benefits of the cloud. Does your business have a strong need to add features, scale or improve performance? If so, refactoring may be the ideal choice, allowing you to unlock the benefits of cloud features otherwise difficult to achieve through other migration approaches.

• Scaling up or restructuring code. Is your organization looking to scale an existing application or restructure its code? You can take full advantage of cloud capabilities by migrating via the refactoring process.

• Boosting agility. If your organization seeks to boost agility or improve business continuity by moving to a service-oriented architecture, then this strategy may be worth pursuing – even though it is often the most cost-intensive solution in the short/medium-term.

How to refactor?

Once you’ve determined whether refactoring is the right migration process for your organization, the next step is to determine how to refactor. There are in general, four ways to refactor your applications for the cloud.

1. Complete Refactoring

In this type, 50% of the code is changed and the database is updated to utilize as many cloud-native features as required by the application. This strategy can improve performance, operational costs and IT teams’ ability to meet the needs of the business. Conversely, however, the complete refactoring process can also be costly and complex, with the risk of introducing bugs.

2. Minimum Viable Refactoring

This approach requires only slight changes in the application and is therefore both quick and efficient. Users who take this approach often incorporate cloud-native security, management and a public cloud database into their migrated workload.

3. Containerization Refactoring

In this method, applications are moved into containers with minimal modifications. The applications exist within the containers, which enables users to incorporate cloud-native features and improve portability.

This approach is often considered to be more complex because of the learning involved in adapting to new tools – however, with the rising popularity of containers and their expanding ecosystems, both costs and refactoring times are steadily decreasing.

4. Serverless Application Refactoring

This approach brings similar issues to containerization, since it changes the development and operations platform, which demands the learning of new tools and skills. Some modifications are required to make the application work effectively and take advantage of serverless systems on the public cloud. Unlike containers, however, serverless platforms don’t provide portability, so lock-in is a major downside to this approach.

It’s possible to refactor your applications through any of these four approaches, but in general, Minimum Viable Refactoring is advisable for most needs. Refactoring is a highly variable process, dependent on the complexity of the current application, and it’s not possible to predict exactly how long an application refactor will take during a discovery assessment process. In general, timelines may range from three to six months per application, depending on their complexity.

Therefore, aligning on a clear target timeline, refactoring in parts and performing regular progress checks with collected data are key best practices to ensure your refactoring migration process proceeds smoothly.

Do you need to shift business-critical applications to, or even between, clouds? Material’s cloud migration experts can recommend an approach tailored to your organization’s unique needs and goals. Reach out today to schedule a consultation with our expert team.