In the current economic environment, IT organizations are increasingly relying on the cloud to upgrade legacy infrastructure and systems. In a growing number of business and industry sectors, cloud migration becomes vital to enable you to continue competing in the market with your products and services. To properly implement cloud migration, however, it is necessary not to make missteps, making mistakes that could compromise the validity of the IT infrastructure modernization project.
What Cloud Migration Means
Performing a cloud migration means moving, entirely or partially, an organization’s IT resources (databases, data, services, applications) from on-premises computing systems to the cloud. However, in the current context of cloud development maturity, cloud migration can also mean moving applications and business data from one cloud platform to another.
Cloud Migration: Why Weigh Your Decision
The first mistake to avoid is believing that cloud migration brings benefits regardless of how it is implemented. It is in fact important, first of all, to analyse, in your business reality, the specific use case that can derive business value from cloud migration, identifying the applications and data that will be necessary to migrate on the cloud, and in what ways. In other words, it must be clear what entrepreneurial benefits and goals justify starting and implementing the cloud migration project for certain business processes and functions. It is also essential to accurately evaluate the operating requirements and performance that each application transferred to the cloud will need to maintain.
Cloud migration challenges
When identifying and selecting data and applications for cloud migration in your enterprise IT infrastructure, you also need to understand, for each, how easily the operation can be performed. Therefore, it will be necessary to evaluate, for example, to what extent a given application can be transferred to the cloud without performing code changes, or whether it is more cost-effective to modify, or even rewrite, it to make it compatible with the new architecture.
Cloud Migration Models, Pros and Cons
For the reasons just explained, it is advisable to operate cloud migration following, depending on the case, different deployment models: from this point of view, regardless of the possibility of using a public, private, hybrid cloud, or multicloud infrastructures, and of adopting an IaaS (infrastructure as a service), PaaS (platform as a Service) or SaaS (software as a Service) service model, It is essential to decide what type of migration approach to adopt for each application. Let’s analyze the main models, with their pros and cons.
Rehosting
The approach of moving an application, as it is, from the local data center (on-premise), directly to the cloud, without modifying its code, is called rehosting (lift-and-shift migration). This cloud migration model has the advantage of avoiding application development and testing costs, but the disadvantage of not fully leveraging the benefits of the cloud: this is because, for example, a legacy application moved, as it is, on the cloud lacks the scalability and ability to handle distributed workloads, which instead has a cloud-native application built specifically for the cloud. Rehosting may also create latency, performance, compliance issues, and malfunctions in your application.
Refactoring
Another cloud migration strategy is refactoring, which involves partially or fully rearchitecting and optimizing application code to enable it to leverage the agility and scalability of IT resource management provided by the cloud. Refactoring is, compared to others, a more complex and expensive approach to cloud migration, because it requires changes to the application code, and subsequent testing activities, to verify that no regression phenomena of existing features occur. However, refactoring, for example through development techniques such as microservices, allows the application to be adapted to new business requirements and made to run efficiently in the cloud.
Replatforming
The replatforming-based cloud migration model can be considered a middle ground between the two previous approaches. Compared to rehosting, replatforming involves making changes to the application code, which are limited compared to a refactoring project. Typically, through replatforming, the benefit is the ability to move only some features and workloads to the cloud, without having to embark on a massive, and costly, cloud migration project. With replatforming, the migrated workloads can benefit from cloud-native capabilities.
Repurchasing
When, during the evaluation phase of existing application software, it is found that a given application is not designed to run in the cloud, then it can also be decided to deactivate it, terminate the license, and replace it with a cloud-based version, available on the market. Typically, this is the case with proprietary legacy applications, such as content management systems (CMS), enterprise resource planning (ERP), and customer relationship management (CRM), which, when replaced with SaaS applications, in addition to eliminating development effort, can also benefit from new performance and functionality.
Retaining
Sometimes, for various reasons, it can be more cost-effective to maintain some legacy applications, as they are, in the on-premise data centre: perhaps because they still work well, or because they are not supported by cloud architecture, or, again, because the company in question must comply with regulations that require maintaining data on-premise. In this case, therefore, the migration strategy must favor hybrid cloud services.
Retiring
A final option also includes the ability to deactivate and decommission certain applications, for example when, during the IT modernization project, software is identified that is no longer in use, supports no longer needed workloads, or performs redundant functions already activated in the cloud.