Refactoring applications for cloud migration: What, when and how

By Gaurav Mishra Sep 27, 2019
Refactoring applications for cloud migration: What, when and how
Refactoring applications for cloud migration: What, when and how

Enterprises migrating their applications to the cloud often face the difficulty of finalizing an approach that is in line with their migration goals. Here are a bunch of questions that can help you in this:

  • What are your business goals?
  • What are your application capacities?
  • What is the estimated cost for your cloud migration process?

Answering these questions, and then selecting the best suitable cloud migration path will guarantee long term success of your enterprise with the migration approach you choose.

In this post, we take a look at one of the most popular methods of cloud migration: Refactoring, what is it and when should you choose it?

What is refactoring migration?

Refactoring is the process of running your applications on the infrastructure of your cloud provider, that is, you will need to completely re-architecture your applications to better suit the new cloud environment. This approach involves modifying your existing applications, or a large chunk of the codebase in order to take better advantage of the cloud-based features and the extra flexibility that comes with them.

Refactoring migration is found to be more complex than the other cloud migration approaches because while making application code changes, you must also ensure that it does not affect the external behavior of the application.

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

This approach is the most time-consuming and resource-intensive of all approaches, yet it can offer the lowest monthly spend in comparison. We further take a look at the benefits, and limitations it has to offer:

Benefits of Refactoring

Most benefits of refactoring are delivered in the future. They include:

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

  • 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 events: 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

The disadvantages of this approach include:

  • Vendor lock-in: The more cloud-native your application is, the more tightly it is coupled to the cloud you are in.

  • Skills: Refactoring is not for beginners. It requires the highest level of application, automation and cloud skills and experience.

  • Time taking: Because refactoring is resource-intensive, and much more complicated in terms of changing from a non-cloud application to a cloud-native application, it can take a lot of time to complete.

  • Getting it wrong: Refactoring requires changing everything about the application, so it has the maximum probability of things going sideways. Each mistake can cause delays, cost escalations and potential outages.

Refactoring is a complex process, but it is well worth the improvement that you get in return. Some companies even go as far as refactoring parts of their business solutions to make the whole process more manageable. This compartmentalization could also lead to refactor becoming longer and more resource-intensive.

When to choose refactoring?

Now that you are aware of the advantages and limitations associated with Refactoring approach, the next step is to identify when you should choose this approach. Take a look:

  1. Efficiency is a priorityRefactoring has the promise of being the most efficient cloud model because your application is cloud-native, and will exploit continuous cloud innovation to benefit from reducing costs and improvements in operations, resilience, responsiveness and security.
  2. Enterprise wants to tap the cloud benefits
    Does your business have a strong need to add features, scale, or performance? If so, refactoring is the best choice for you. Exploiting the cloud features will give you benefits that are otherwise difficult to achieve in an existing non-cloud environment. 
  3. Scaling up or restructuring code
    Is your organization looking to scale an existing application, or wants to restructure their code? You can take full advantage of cloud capabilities by migrating via the refactoring process.
  4. Boost agility
    If your organization is looking to boost agility or improve business continuity by moving to a service-oriented architecture, then this strategy may be worth pursuing. And that’s despite the fact that it is often the most expensive solution in the short-medium term.

How to refactor?

So you know when to choose refactoring, the next question is how? 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, operations costs and IT teams' ability to meet the needs of the business. On the downside however, the process could be too costly or complex, and can introduce bugs.

2. Minimum Viable Refactoring

This 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 perhaps a public cloud database into their migrated workload.

3. Containerization Refactoring

In this, 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 found to be more complex because of the learning involved in adapting to new tools. But that is easily checked, as with the popularity of containers and their growing ecosystems, the costs and refactoring times continue to decrease.

4. Serverless Application Refactoring

This approach has similar issues as containerization as it changes the development and operations platform, which requires learning 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.

You can refactor your applications using either of these ways, but it is advisable to do Minimum Viable Refactoring for most of it. Refactoring is a highly variable activity, dependent on the current application complexity. And during its discovery assessment process, it’s not possible to predict how long an application refactor will take. It could be around three-to-six months per application depending on complexity and previous experience.

Hence, a targeted timeline, refactoring in parts, and checking progress with collected data are some of the best practices to keep in mind while taking up Refactoring cloud migration approach. Because of these reasons, this approach is chosen by very few enterprises that have the time, money, and resources for it.

Looking to shift business-critical applications to or even between clouds? Just drop us a line and our expert team will be in touch.

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