The fundamentals of Cloud Migrations

One of the most common cloud migration scenarios entails moving a portion of an organization’s on-premises applications, services, and data to a public cloud infrastructure as a service (IaaS), which is roughly analogous to the on-premises data center. Other common variations are cloud software as a service (SaaS) and platform as a service (PaaS); these are application and platform services that aim to mask much of the complexity involved in configuring, managing, and maintaining IT resources.

What are the top reasons for doing Cloud Migration? Following are top business drivers:

Data Center Exit: Customers run their applications within a data center that supplies the required Compute power, network, and storage. This data center is often called the on-premises data center. And that will have a lease agreement signed between multiple parties for a specific term.
Cloud migration would help a customer to exit his data center and migrate all his applications into a public Cloud like Oracle Cloud Infrastructure. On-premises data centers are managed and operated by the customers themselves.

Reduced Operational and Infrastructure Costs: This would involve operational costs. That means there are operational engineers who are assigned to monitor and manage the environment. And then there are infrastructure costs. A new set of hardware and software needs to be procured and installed based on requirements. The way to reduce all these costs is to migrate resources into the Cloud.

Business agility and flexibility: Cloud provides business agility and flexibility. There is always a need to deploy IT resources quickly as possible to satisfy business requirements.
Cloud environments are highly flexible. So, these resources can be provisioned on demand, or even decreased depending on business need.

Business continuity: It ensures the organization can continue to function during disruptions and even during a disaster.

Business Growth: Cloud services are designed to protect with continuous availability. And it offers fast, reliable, and disaster recovery support. One of the key business drivers for Cloud migration is to support business growth. Every organization is looking to expand their business.

Improved Security: Security has always been a top priority. With migrating into the Cloud, this provides additional layers of security to secure the entire environment, whether it be your infrastructure, databases, web-based applications. There are much improved security services to protect all of these resources.

Like business drivers, there are technical drivers that lead to Cloud migrations.

Hardware and Software End of Support: As a customer when you run an on-premises data center, you are required to run your own specific hardware and software. These resources do have a lifecycle management associated to it, meaning there will be an end of support time. And then after you are required to upgrade or purchase a new set of hardware.
By migrating into the Cloud, you are provided with Cloud services that serve the same purpose of those resources.

Scalability: It is another key factor. And in a Cloud environment, resources can be automatically provisioned or decommissioned based on demand. All resources in a Cloud are designed to be highly resilient to avoid any single point of failures.

Improved Performance: A public Cloud environment like OCI uses an architecture to provide the best performance for any IT resource. 

Address Resource Limitation: With migrating to the Cloud, you could address any of the resource limitations because the Cloud services are highly efficient and provided in the form of a service accessible through a simple browser.

Modernize Application: Data centers could be running legacy applications. And with migrating into the Cloud, this would allow to modernize these applications.

Technology Integration and Innovation: Cloud Migrations opens up the door for further innovations that provides a wider scope of integrating apps with the latest and greatest technologies within the Cloud.

Now, let's check out the cloud migration strategies. 

Re-host is the name of the first one. It's known as migration, or just moving applications, unaltered, from a source into a target. This might have to do with moving virtual machines (VMs) from an on-premises VMware system to an Oracle Cloud VMware solution.

The second tactic is known as "Re-platforming". This has to do with moving apps to a new target platform that has a different shape. This can involve moving a virtual machine (VM) from an on-premises VMware system to an OCI compute instance.
 
Re-architect is the term for the third one. It's also known as re-factoring. This entails moving application to a different target platform that has a more recent architecture. Moving virtual machines into containers in OCI Container engine for OKE or Kubernetes would be one example of this

Repurchase is the next tactic in this case. The benefit of decommissioning apps in the source is offered by this method. and buy in the intended Cloud environment as software as a service.
 
Re-build is the last tactic. We have to start from scratch when designing and writing applications in this case.