Five Cloud Migration Strategies for Applications

Regardless of your current IT environment or your vision for migrating to the cloud, numerous strategies exist that can accommodate your cloud-migration approach. Fortunately, this range of options allows you to proceed with caution while making progress toward your ultimate objective.
Always keep in mind that transitioning to the cloud need not be an “all or nothing” proposition. It is certainly possible, and indeed in many cases desirable, to leave some applications running in a local, traditional data center while others are moved to the cloud. It’s this “hybrid model” that makes it possible for companies to move applications to the cloud at their own pace.
We looked at service and deployment models for migrating to the cloud in our last post. This article provides summary descriptions of the options available to you when considering your cloud migration initiative.

Top Five Cloud Migration Strategies

1. Re-hosting

Sometimes referred to as “lift and shift,” re-hosting simply entails redeploying applications to a cloud-based hardware environment and making the appropriate changes to the application’s host configuration. This type of migration can provide a quick and easy cloud migration solution. There are trade-offs to this strategy, as the IaaS-based benefits of elasticity and scalability are not available with a re-hosting deployment.
However, the solution is made even more appealing by the availability of automated tools such as Amazon Web Services VM Import/Export. Still, some customers prefer to “learn by doing,” and opt to deploy the re-hosting process manually. In either case, once you have applications actually running in the cloud they tend to be easier to optimize and re-architect.
Re-hosting is particularly effective in a large-scale enterprise migration. Some organizations have realized a cost savings of as much as 30 percent, without having to implement any cloud-specific optimizations.

2. Re-platforming

This strategy entails running applications on the cloud provider’s infrastructure. You might make a few cloud-related optimizations to achieve some tangible benefit with relative ease, but you aren’t spending developer cycles to change an application’s core architecture.
Advantages of re-platforming include its “backward compatibility” that allows developers to reuse familiar resources, including legacy programming languages, development frameworks, and existing caches of an organization’s vital code.
An unfortunate downside to this strategy is the nascent state of the PaaS market, which doesn’t always provide some of the familiar capabilities offered to developers by existing platforms.

3. Repurchasing

This solution most often means discarding a legacy application or application platform, and deploying commercially available software delivered as a service. The solution reduces the need for a development team when requirements for a business function change quickly. The repurchasing option often manifests as a move to an SaaS platform such as Salesforce.com or Drupal. Disadvantages can include inconsistent naming conventions, interoperability issues, and vendor lock-in.

4. Refactoring / Re-architecting

This solution involves re-imagining how an application is architected and developed, typically using the cloud-native features of PaaS. This is usually driven by a strong business need to add features, scale, or performance that would otherwise be difficult to achieve in the application’s existing environment.
Unfortunately, this means the loss of legacy code and familiar development frameworks. On the flip side, it also means access to world-class developer’s tools available via the provider’s platform. Examples of productivity tools provided by PaaS providers include application templates and data models that can be customized, and developer communities that supply pre-built components.
The primary disadvantage to a PaaS arrangement is that the customer becomes extremely dependent on the provider. The fallout from a disengagement with the vendor over policies or pricing can be quite disruptive. A switch in vendors can mean abandoning most if not all, of a customer’s re-architected applications.

5. Retiring

Typically, the initial step in the cloud migration process is the discovery of your entire IT portfolio. Often, this discovery process entails application metering to determine the actual usage of deployed applications. It’s not unusual to find that anywhere between 10 to 20 percent of an enterprise IT estate is no longer being used. Retiring these unused applications can have a positive impact on the company’s bottom line; not just with the cost savings realized by no longer maintaining the applications, but by allowing IT resources to be devoted elsewhere, and by minimizing security concerns for the obsolete applications.
Download our Cloud Migration Guide to learn more about approaches and security considerations for migrating your applications and data to the cloud.