Understanding Cloud Migration and Strategies

Hello Folks, Welcome back to Learnizo Global. Cloud computing provides a new platform for any organization that promises flexible scalability, business agility, high availability, and reduction in costs. Considering these benefits, the migration of legacy systems to the cloud is a lucrative option for many organizations. In this article, we will understand the need, process, and strategies for Cloud Migration.

What is Cloud Migration?

Cloud migration is when an organization transfers applications and associated data from on-premises data centers to the cloud. These applications can be applications an organization made itself or were purchased to serve a business-critical function. Cloud migration can be done by optimizing portions of the application for the cloud, modifying the application’s base code so it integrates with the cloud better, or simply adopting an application already in the cloud to replace the original application.

Migrating to the cloud becomes necessary when an organization’s own application needs to scale beyond the capabilities of its on-premises data center. Another reason to migrate is if an organization has legacy applications that are no longer supported by the applications’ vendors. These outdated applications do not receive security patches and are less secure.

There are significant benefits to cloud migration. For instance, compared to an on-premises data center, a cloud is less difficult to work with and maintain, the operating costs are much lower, and with a cloud-native approach, applications can be fixed much faster. However, a cloud-native approach could mean legacy applications must be changed significantly.

Cloud Migration Techniques and Strategies

There are several different techniques for bringing legacy applications into the cloud, ranging from simply putting the legacy applications as they are into the cloud, to creating a replacement application from scratch. We will discuss a few of them here.

Lift-and-shift is an approach where an organization’s own applications are not changed from their original versions and are simply re-hosted in the cloud instead of the on-premises data center. Lift-and-shift can involve copying the application binaries, creating and configuring virtual machine (VM) images, establishing security groups, setting up elastic IP addresses and domain name systems (DNS), and switching to a new database in the cloud. This can couple with a cloud provider’s infrastructure-as-a-service (IaaS) infrastructure.

Refactoring or re-platforming is when already-existing code and application frameworks are reused, but the application runs on a platform-as-a-service (PaaS) platform rather than an IaaS. The core architecture is not changed; the application mostly becomes optimized in part for the cloud.

Revise means an organization partially modifies or otherwise expands the codebase before deploying it to the cloud.

Rebuilding is when an application is rewritten or re-architected from the ground up by using the cloud provider’s PaaS platform. This is usually a labor-intensive approach but has considerable benefits by taking advantage of modern technologies and features.

Retirement is when an organization finds areas of its application portfolio that are no longer useful, so they are turned off and not used moving forward. By removing the extraneous applications, an organization can save money, bring an IT team’s focus to what is important, and decrease the surface area that must be secured. Extraneous applications may include purchased applications.

Replacement or repurchasing is simply moving to a new product and away from an original application the organization made for itself, or from a purchased application. These new applications are software-as-a-service (SaaS) applications from the cloud provider or a third party. This can be seen with an organization moving from a customer relationship management application that an organization developed or purchased to Salesforce or a similar service.

Hybrid and phased migrations are two similar approaches to using most of the above techniques. They emphasize moving the application to the cloud in parts. Each part is optimized for the cloud individually and the different parts are able to communicate via interfaces designed for the cloud environment.

Types of Clouds Available for Migration

An organization can choose between public, private, and hybrid clouds for migrating applications and data.

By choosing a public cloud, an organization’s applications and data are entirely hosted by the cloud provider or providers they choose. Organizations using the public cloud can have their employees access the applications the employees need from anywhere there is an internet connection.

A private cloud, likely a hosted private cloud in this context, is a pool of compute, storage, and networking resources dedicated to one organization but exists in a provider’s data center. The hosted private cloud may have other organizations using the data center, but each organization’s infrastructure is inaccessible to the others. Private clouds are the most secure type of cloud and are good for storing sensitive data and running applications that use said data.

A hybrid cloud can provide a more holistic approach to using the cloud because it is a combination of public and private cloud services. Essentially, when there is high enough demand, workloads can be run in the public cloud and then return to the private cloud when there isn’t as much demand. This reduces how much is spent on cloud resources. Additionally, sensitive data and applications can be kept in the private cloud while less-sensitive data and applications can be stored and run in the public cloud.

How to Migrate to the Cloud: The Process

Organizations can use a simple roadmap with three to four high-level steps. These steps typically include assessing their current infrastructure, applications, and goals; planning how the migration will take place; building out the cloud environment; migrating the applications; and then optimizing the cloud environment for the organization’s goals.

The specific number and names of the steps vary depending on the organization. Cloud service providers including Google Cloud, Microsoft Azure, or AWS all offer examples.

Assessment

Organizations looking to migrate to the cloud should start with thorough assessment and inventory into their existing data center environment. This gives organizations a clear scope of the current resources required to run their applications and services. An organization should also take this time to assess which applications are business-critical and which aren’t. This will likely be a joint effort between IT teams and business managers.

The assessment phase is also when an organization should calculate the total cost of ownership (TCO). An organization will learn whether migrating to the cloud is a good fit for its goals and budget.

At the end of the assessment, an organization should decide which cloud provider best fits its needs, what kind of cloud service model to use, and which applications to migrate first based on its research. The cloud service models are platform-as-a-service (PaaS), infrastructure-as-a-service (IaaS), and software-as-a-service (SaaS).

Planning

Once an organization is sure migrating to the cloud is a good fit, it begins planning for the cloud migration process. The primary aspects of planning are determining what applications need changing and to what extent. This part of planning is acted on with the migration techniques listed above.

Organizations should factor application updates into their cloud migration timeline. If the organization determines applications need serious updates, it can delay migrating to the cloud. If applications are just shoved into the cloud as is, then the benefits of the cloud won’t be realized.

Planning also includes assigning roles and permissions to different general types of identities the organization assigns to its employees. Different identities will have different levels of access to cloud resources. With that figured out, an organization can establish the topology of its cloud environment. In this case, topology refers to how the cloud environment is divided up and how those sections communicate.

Executing Migration

When an organization is ready to migrate to the cloud, it should have completed any modifications to applications needed for cloud readiness. All other aspects of planning for the cloud, like setting up the cloud environment, should be completed as well. Cloud providers offer several tools to assist with the actual migration process through automation, though a fully manual approach is always an option. A drawback to manual migrations is the increased chance of human error.

Optimization

Depending on the migration technique used for each application, there are different degrees to which the benefits of the cloud can be leveraged.

For example, a lift-and-shift approach where the application was minimally modified to work in the cloud means the application cannot scale very well and make it hard for administrators to control its resource usage. On the other hand, an application that was rebuilt from the ground up can scale easily and its resource usage can be granularly controlled.

Optimizing for the cloud can mean reworking applications once they have been migrated so they can benefit more from the cloud’s features. It can also mean learning how to use the cloud more efficiently for the organization’s applications. For example, by monitoring application usage, an organization can work on the application’s code, or it can change the number of resources the organization wants to provision to the application.

We shall discuss in detail about Cloud Native approach in our further articles. Till then stay safe and happy learning with Learnizo Global