Cloud Adoption Decision-Making: Rehost, Refactor or Rebuild?

Are you a cloud candidate? This is a question that should be answered with care. Many businesses are striving to modernize applications or assets by migrating to the cloud. There are three key ways to handle your cloud adoption strategy or cloud migration: rehosting, refactoring or rebuilding (rearchitecting). To steer you in the right direction, let’s examine the advantages, with a following word of caution for each process.

Rehosting

Rehosting is frequently described as a “lift and shift” process, where an application or state asset is moved to the selected cloud provider, with the notion of taking advantage of the new cloud infrastructure. The process, however, encompasses minimal changes to code and the application itself.

Rehosting Benefits

• Cost-efficient — utilising this particular cloud adoption process is definitely cost-effective because it avoids any major development or additional work.
• Zero changes to code — applications are rehosted to the cloud with no significant code changes, eliminating costly development and testing.
• Zero changes to architecture — once applications migrate to the cloud, no major alterations are made to surrounding infrastructure, or business process. In other words, event management and monitoring ports remain unaffected.
• Scale as needed — when rehosting, you’re essentially moving workloads to the cloud, and testing the waters so to speak with the cloud environment; once that is done, you can move to other workloads, without committing to a large migration effort.
• Some cloud-native functionality — rehosting allows applications to leverage certain cloud capabilities like auto-scaling, managed storage and data processing services, infrastructure as code (IaC), and more.

Rehosting – Be Mindful of

Rehosting is not usually the best choice when moving to the cloud, so here are certain factors you should be aware of:

• Drastic changes — stick to well-known cloud components, and avoid any aggressive alterations to the application, unless absolutely necessary or essential to business value.

• Disregarding application requirements – take heed during the migration process. The whole thing can collapse easily, if the application requirements aren’t properly mapped out to correspond to cloud configuration.

• Performance and latency – the fast approach of rehosting often means your application is not tailored to the new infrastructure or environment as meticulously as it can be. This usually results in poor performance and latency issues.

• Neglecting full advantages of the cloud – sure rehosting may seem like a handy shortcut, but the public cloud platform has a remarkably wide range of benefits, most of which will remain unused with the lift and shift process.

Refactoring

Having a solid cloud adoption strategy means you need to understand how the migration process works. Okay, so, we’ve already taken a high-level look into Refactoring Legacy Applications for the Cloud and refactoring in general. Refactoring, also known as “repackaging,” denotes small changes to applications so that they can connect to the cloud platform. When refactoring, you must consider the portability of your current code base and available development skills. Still, the process does bring benefits, so it’s definitely worth considering.

Refactoring Benefits

• Scaling and long-term cost reduction — thanks to the scalability of the cloud, certain benefits come into play here. To give a more accurate example: when rehosting you are moving a single on-premise server to one cloud-based VM, although when refactoring, you move to multiple lightweight VM instances; hence it’s possible to scale the application up and down as needed. This effectively decreases resource consumption. Essentially, you’re reducing costs and gaining long-term ROI.

• Decoupling and improved resilience — the moment you’ve decoupled your application components and then reassembled with managed solutions, the application immediately assumes cloud-powered resilience, or rather durability.

• Agility and adaptability — anything that you’ve set up within your application configuration to be cloud-native involves high adaptability. Microservices architectures and cloud-native applications can adapt to new user/customer needs, by easily changing current functionality or adding brand new features.

Refactoring – Be Mindful of

• Waiting — refactoring is resource-intensive and more complex than a lift-and-shift migration; meaning projects take much longer to start showing real value for the business.

• Misinterpretation and lack of expertise — as a method of migration, refactoring is elaborate and not something to be taken lightly. The process involves high DevOps skills, expert code knowledge, enabling automation and more.

• Cost escalations and outages — if the code isn’t handled with care and scrutiny, refactoring can bring errors in configuration and infrastructure. This may lead to escalation in expenses, outages and other consequences that can have a negative impact your business.

Rebuilding

Legacy applications traditionally aren’t compatible with public cloud infrastructure. Decisions that were made way back when the application was being created do not align with the modern-day cloud environment. Rehosting or refactoring may not be the answer here. Rebuilding, which involves a complete rewrite towards cloud-native architecture, is just the ticket for your cloud adoption strategy.

Rebuilding Benefits

• High mobility and flexibility — well-designed rearchitecture creates a pure, cloud-native application, which yields tremendous long-term ROI, and also builds the foundation for additional flexibility for any emerging future tech.

• Strong security — the cloud environment involves tighter, more modern security.

• Taking full advantages of cloud — with a complete rebuild or rewrite, your application has become cloud-native, thus inheriting all the benefits that come with the power of the cloud, scalability, resilience, powerful underlying infrastructure, and so on.

Rebuilding – Be Mindful of

• It’s time-consuming and involves heavy resources — doing something as intricate as a full rewrite for the cloud, involves a lot of time, work and calculation that include application asset size (CPU, memory, storage), dependencies (network traffic), and so on.

• Increased expenses — such a process is costly, given the amount of work that is involved, but bear in mind that with growing business investments and operational costs, progress won’t be far behind.

• DevOps complexity and potential feedback loops — rebuilding involves a lot of development, and can require a lot of work in code, new builds, commits, updates, tests and various feedback that naturally comes along with such an intricate process.

It’s All Powered by Code

Everything is powered by code, and make sure your own code is up-to-date and ready to rely on cloud capabilities. Core components of your application need to have a well-structured relationship with databases and infrastructure. The perfect cloud adoption strategy is just around the corner, but you need to prepare for it.

Remember, the goal through each process isn’t just to move with the times, but to stay ahead of them and be prepared for anything that’s coming.

The technology market is evolving fast, and whether you’re rehosting, refactoring or rearchitecting your applications, the objective should always be the same – to become cloud-native and resilient.