What is the public cloud?
A public cloud is a set of computing services offered by a third party through the internet. From a deployment standpoint, there are three types of cloud computing. There’s the public cloud, the private cloud, and the hybrid cloud. Of these three types, the public cloud requires the lowest capital expenditure (CAPEX). It’s also the most scalable. If those qualities are enough to pique your interest, do stick around.
This post, talks about how a public cloud works, what factors make a cloud “public”, the services offered under this model, the benefits and drawbacks of this cloud model, and more.
How does the public cloud works?
Any type of cloud service is built on top of physical IT infrastructure (servers, storage devices, networking, etc.), virtualization software, and cloud automation and orchestration tools. In the case of a public cloud, all these underlying components are managed by a third party known as a cloud service provider (CSP). If you’re a public cloud customer, you’re basically outsourcing these components and the management of these components to your CSP.
For comparison, in a private cloud, everything is owned and managed by the organization itself. None of those components are outsourced to a third party.
The cloud services provided by a CSP to customers are delivered as:
- Virtualized IT infrastructure, as in the case of Infrastructure as a Service (IaaS).
- Virtualized applications, as in the case of Software as a Service (SaaS).
- Virtualized development and deployment platforms, as in the case of Platform as a Service (PaaS).
The CSP also provides customers with an administrative interface for deploying and managing their virtualized IT infrastructure, applications, or platforms. Through these administrative interfaces, you can, for example, spin up and spin down virtual machines; add computing resources like CPU, RAM and storage; specify access rules; and so on.
Public cloud services are delivered through the internet. Customers usually access and manage these services through a web browser. That means, as a cloud customer, you can access public cloud services from practically anywhere as long as you have an internet connection.
CSPs typically have several data centers that house their cloud infrastructure. These data centers are scattered around the globe. The bigger the CSP, the wider its global reach. Hence, when you subscribe to any of the large public cloud providers like Amazon Web Services (AWS), Azure, and Google Cloud, you can create and access cloud-based assets with very little latency.
What makes a cloud public?
There are three key ingredients that make a cloud public:
- Shared infrastructure. When cloud customers, aka tenants, share the underlying infrastructure (physical servers, physical network, virtualization software, etc.), this setup characterizes a public cloud.
- Outsourced infrastructure management. When a CSP manages the underlying infrastructure for you, you’re dealing with a public cloud.
- Flexible payment. One more key ingredient that characterizes a public cloud is a flexible payment scheme such as a subscription-based or consumption-based payment model. Customers consume cloud resources and then pay on a monthly or annual basis. In some cases, customers also pay based on the amount of resources they consume over a given period.
What are public cloud services?
Public cloud services traditionally come in three types. Yes, there are now several other public cloud services like Desktop as a Service (DaaS) and Security as a Service (SECaaS), but these three are the most established types.
Infrastructure as a Service (IaaS)
IaaS is a public cloud service wherein cloud customers consume virtual machines (VMs) as well as their constituent resources such as CPU, RAM, and storage. Customers are responsible for managing those virtual machines as well as whatever software they (the customers) install on those VMs. AWS EC2 and Azure VMs are two examples of IaaS offerings.
You typically subscribe to IaaS if you want to set up a virtual IT infrastructure but use specific operating systems and applications and want full control over those pieces of software. Your skill requirements are going to revolve around IT, system administration, or basically any skill set that can not only deploy, configure, manage, and secure OSs and applications, but also set up VMs and virtual networks.
Platform as a Service (PaaS)
PaaS is a cloud service wherein customers are given access to a set of software development tools. These tools range from design and development all the way through testing and deployment. Examples of PaaS offerings include Google App Engine and Heroku.
You normally subscribe to a PaaS service if you wish to develop software but want to avoid the hassle of building the required hardware and software infrastructure. As you might have already gathered, the required skill sets for using PaaS are those associated with software developers.
Software as a Service (SaaS)
SaaS is a public cloud service wherein customers only interface with an application, which is delivered as a service. Unlike in IaaS, SaaS cloud customers no longer have to worry about CPU, RAM, storage, VMs, or even operating systems. They don’t even have to worry about installing the application itself. Google Drive and Salesforce CRM are two examples of SaaS solutions.
You normally subscribe to a SaaS service if all you want is to use a specific application. Your skill requirements are going to be less technical than those in IaaS or PaaS. For the more advanced SaaS solutions, it would help if you had people whose expertise aligns with the SaaS solution in question. For example, if you’re using HubSpot, it would help if the people in charge of it knew inbound marketing basics.
What are the benefits and drawbacks of public cloud computing?
Using public cloud computing has both benefits and drawbacks.
Benefits of using a public cloud
The public cloud provides multiple advantages such as eliminating CAPEX, providing scalability, minimizing overhead, streamlining cash flow, and encouraging innovation.
Enables zero CAPEX
The biggest benefit of using a public cloud is that it enables you to avoid the large (CAPEX) associated with building an on-premises IT infrastructure. With a public cloud, your CSP takes charge of purchasing, deploying, managing, and maintaining physical servers, networking, and storage devices.
Not only that, your CSP will also build and manage the facilities (basically data centers) that host the infrastructure as well as the supporting equipment like cooling systems, power generators, physical security and so on.
Provides infinite scalability
Public cloud service providers run massive data centers that can provide an almost unlimited supply of computing resources. For IaaS offerings, it means simply adding more CPU, RAM, storage, or even entire virtual machines whenever the need arises. For SaaS and PaaS, it simply means upgrading to a bigger plan that supports more users and features.
As a result, you can easily grow your infrastructure as your computing demand increases. This capability is perfect for rapidly growing businesses or for industries with seasonal demands.
Reduces administrative overhead
When you use a public cloud, not only do you free yourself from costly capital expenditures, you also eliminate a substantial amount of administrative overhead. In all types of public cloud services, you don’t have to manage facilities, physical security, HVAC equipment, and physical IT infrastructure. if you’re a SaaS customer, you don’t even have to deal with operating system and application maintenance and upgrades.
This reduction of administrative overhead takes away several barriers to entry into certain technologies. For example, if you want to develop software, you just hire software developers and subscribe to a PaaS service. You don’t have to hire IT staff to build and maintain the underlying infrastructure anymore.
Streamlines cash flow
Public cloud services are characterized by flexible payment schemes that follow a subscription-based or consumption-based model. These flexible plans can have a substantial positive impact on your cash flow because you don’t have to pay up front. In a traditional on-premises IT setting, you have to produce a capital outlay equivalent to a projected peak demand even if the demand is not yet there. That’s going to constrain your cash flow.
A public cloud’s flexible payment model is better because you only spend as the need arises. If demand picks up, then you can gradually increase your public cloud spend. That’s alright because an increase in demand likely also means an increase in your income.
Drives innovation
By helping you avoid unnecessary administrative overhead and capital expenditure, public clouds pave the way for innovation. Since you’re no longer held back by financial and administrative constraints, you can try out new ideas more often. You can build more test environments or develop more software applications.
That’s not all. Large public cloud providers like AWS, Azure, and Google Cloud constantly offer the latest technologies through the same cloud-based model. Want to see how you can benefit from relatively new technologies like serverless, containers, big data, or artificial intelligence? You can easily do that without breaking the bank through a public cloud.
Drawbacks of using a public cloud
The public cloud is not all sunshine and rainbows though. There are some disadvantages of using a public cloud.
Diminishes control over IT infrastructure
Not all organizations want to relinquish control of their IT infrastructure to a third party. Large enterprises that require highly customized set ups engineered by their own IT team can’t find their desired level of control in public clouds. If you recall, you don’t get to engineer and administer the underlying physical infrastructure in public clouds.
Introduces runaway costs
The flexible OPEX-based model inherent in public clouds is not without flaws. When mismanaged, public cloud resource consumption can lead to runaway costs. Cloud users who are given free reign can end up consuming more resources than are necessary. If this happens, the total cost of ownership (TCO) of a public cloud can far exceed that of an on-premises IT infrastructure.
Complicates data privacy policies
Since public cloud infrastructures are multi-tenant (i.e., shared by multiple customers), you always run the risk of a data leak. This can be a problem if you need to implement stringent data privacy policies. You need to apply additional security measures to mitigate that risk.
What’s the difference between a private cloud and public cloud?
The fundamental technologies employed in a private cloud—e.g., virtualization solutions, cloud automation, and orchestrations solutions are similar to those used in a public cloud. There is only one main difference. A private cloud isn’t managed by a third party. If you operate a private cloud, everything from the software to the physical hardware down to the data center facility itself will be managed by your own people.
While a private cloud eliminates the drawbacks of a public cloud (lack of control, runaway costs, privacy issues), it also diminishes all the benefits mentioned earlier. Yes, you might still enjoy lower CAPEX by way of virtualization, but it will no longer be zero CAPEX. You may realize reduced administrative overhead due to virtualization, cloud automation, and cloud orchestration, but the reduction won’t be on par with those in a public cloud.
You also won’t enjoy infinite scalability because, in order to scale, you will have to add more physical IT infrastructure and not just virtualized resources.
To acquire both public and private cloud benefits, some businesses adopt a hybrid cloud computing strategy, which basically combines a public cloud infrastructure with a private cloud infrastructure.
Flexible cloud deployment with Parallels RAS
Organizations that use virtual desktop infrastructure (VDI) solutions to enable remote work often leverage cloud computing to deliver scalable, globally accessible, and cost-effective remote work environments. To maximize the full potential of cloud computing and VDI, you need a VDI solution that supports multiple cloud deployment models. Parallels® RAS has that capability.
Parallels RAS fully supports multiple cloud deployment options including public cloud, private cloud, and even hybrid cloud deployments. With Parallels RAS, you can deliver virtualized applications and desktops anytime, anywhere from the cloud environment of your choosing.
This deployment flexibility ensures you can take advantage of the public cloud’s scalability, payment flexibility, and zero CAPEX attributes along with the private cloud’s ability to provide control and data privacy wherever appropriate.
See how Parallels RAS leverages the full potential of public clouds.
