What is public cloud? Everything you need to know

A public cloud is a platform that uses the standard cloud computing model to make resources — such as virtual machines, applications, or storage — available to users remotely. Public cloud services may be free or offered through a variety of subscription or on-demand pricing schemes, including a pay-per-usage model.

The main benefits of the public cloud are as follows:

a reduced need for organizations to invest in and maintain their own on-premises IT resources;
scalability to meet workload and user demands; and
fewer wasted resources because customers only pay for what they use.

How does it work?

Public cloud is an alternative application development approach to traditional on-premises IT architectures. In the basic public cloud computing model, a third-party provider hosts scalable, on-demand IT resources and delivers them to users over a network connection, either over the public internet or a dedicated network.

The public cloud model encompasses many different technologies, capabilities, and features. At its core, however,it consists of the following key characteristics:

on-demand computing and self-service provisioning;
resource pooling;
scalability and rapid elasticity;
pay-per-use pricing;
measured service;
resiliency and availability;
security; and
broad network access.

The public cloud provider supplies the infrastructure needed to host and deploy workloads in the cloud. It also offers tools and services to help customers manage cloud applications, such as data storage, security, and monitoring.

When selecting a provider, organizations can opt for a large, general-use provider — such as AWS, Microsoft Azure, or Google Cloud Platform (GCP) — or a smaller provider. General cloud providers offer broad availability and integration options and are desirable for multipurpose cloud needs. Niche providers offer more customization.

Migration

Numerous factors propel businesses to shift from on-premises facilities to the public cloud. One reason is the need for support for a broader range of workload types that traditional data centers cannot cater to. Cost considerations, reduced overhead maintenance, and the desire for redundancy are also prevalent motivations.

Once a provider is selected, the IT team must decide on a cloud migration method to transfer data to the chosen cloud service. Offline migration involves copying local data onto a portable device and physically transporting the hardware to the cloud provider. On the other hand, online data migration occurs through a network connection over the public internet or a cloud provider’s networking service.

In cases where there is a substantial amount of data to transfer, offline migration is typically faster and more cost-effective. Online migration, however, is suitable for organizations that do not need to move large volumes of data.

Additionally, organizations often integrate existing on-premises applications into the cloud, and several approaches can be considered. The lift-and-shift method moves the application to the cloud without any redesign. While this is a speedy process, it is susceptible to complications, as the application may not function optimally within a cloud architecture and could incur higher costs than if it remained on-premises. Alternatively, IT teams can choose to refactor on-premises applications before migration. Although this method requires more time and planning, it ensures that the application will operate effectively in the cloud. Another option is a complete rebuild as a cloud-native application.

Regardless of the chosen strategy, various cloud-native and third-party migration tools are available to assist in managing the transition to the public cloud.

Public cloud architecture

It constitutes a completely virtualized environment reliant on high-bandwidth network connectivity for data transmission. Utilizing a multi-tenant architecture, providers enable users, or tenants, to execute workloads on shared infrastructure and access the same computing resources. In the public cloud, a tenant’s data is logically separated and remains isolated from the data of other tenants.

Cloud service providers manage these services in logically isolated locations within public cloud regions known as availability zones. These zones typically comprise two or more interconnected, highly available physical data centers.

Organizations make availability zone selections based on compliance requirements and proximity to end-users. For enhanced redundancy and protection against outages, cloud resources can be duplicated across multiple availability zones.

Public cloud architecture can be further categorized by service model. These are the three most common service models:

Infrastructure as a service (IaaS), in which a third-party provider hosts infrastructure components, such as servers and storage, as well as a virtualization layer. The IaaS provider offers virtualized computing resources, such as VMs, over the internet or through dedicated connections.
Platform as a service (PaaS), in which a third-party provider delivers hardware and software tools — usually those needed for application development, including operating systems — to its users as a service.
Software as a service (SaaS), in which a third-party provider hosts applications and makes them available to customers over the internet.

Benefits of public cloud computing

When considering the adoption of public cloud services, enterprises must carefully evaluate the advantages and disadvantages to determine its suitability for their needs.

Advantages

Access to New Technologies: Organizations leveraging large cloud providers gain immediate access to the latest technologies in the IT industry. This includes applications that update automatically, as well as advancements in machine learning and artificial intelligence. Many organizations lack the resources to acquire such access independently.
Virtually Unlimited Scalability: Public cloud infrastructure rapidly expands to accommodate user demands and traffic spikes. Users benefit from enhanced redundancy and high availability due to the logically separated cloud locations maintained by providers. Additionally, public cloud users experience faster connectivity between cloud services and end-users through the provider’s network interfaces, although bandwidth and latency issues may still arise.
Flexibility: The flexible and scalable nature of public cloud storage allows users to easily store and access large volumes of data. Many organizations rely on the cloud for disaster recovery, backing up data and applications in case of emergencies or outages. To manage long-term storage costs and maintain privacy, users should establish a data retention policy that regularly removes outdated data from storage.
Analytics: Gathering useful metrics on stored data and utilized resources facilitates cloud data analytics. Public cloud services can efficiently analyze large volumes of data, accommodating various data types to provide valuable business insights.
Reliable Infrastructure Access: Public cloud users benefit from access to the provider’s reliable infrastructure, reducing the complexities of managing overhead tasks. This enables IT staff to concentrate on more critical business tasks, such as coding applications.

In summary, public cloud computing offers organizations a range of advantages, from technological innovation and scalability to flexibility and analytics capabilities. Additionally, the abstraction of management tasks contributes to a more efficient use of IT resources.

Source: techtarget site