Cloud computing has become ubiquitous for businesses of all sizes, and it offers benefits around scalability, ease of use, fast time-to-market and flexible costs. But cloud isn’t a one-size-fits-all solution, and different workloads perform better in different infrastructure configurations.
IT teams and business decision makers are tasked with determining which type of cloud will work best for their technology requirements, while also finding cloud providers that offer a wide range of deployment options. Understanding the difference between public cloud and private cloud is critical to making the right infrastructure decisions.
Definitions: Public Cloud vs Private Cloud
How do you decide which cloud option is right for you? Let’s look at the definition of public and private cloud along with a few use case examples.
Public cloud allows customers to instantly provision cloud instances via an online portal. As a utility compute model, public cloud provides an accessible, cost-effective cloud deployment option that can be accessed on a pay-as-you-go basis with no upfront investment required.
The flexible billing model with no contract commitment is beneficial for small businesses and other organizations that may only need a cloud server for a limited amount of time, such as for development or testing purposes. The scalability and elasticity offered by public cloud can accommodate changing workload sizes and allow customers to spin servers up and down as needed.
Customization & Control
The public cloud is a multi-tenant environment where the hardware and network resources are shared across customers. All hardware and associated networking are located in a data center where they are maintained by the cloud service provider, which reduces the management burden on the customer. However, because of the commoditized nature of public clouds, customization and control is limited. This can be problematic for organizations with strict security or compliance requirements if the cloud provider doesn’t offer specific hardware or operating systems that meet the company’s needs.
Public cloud offerings are typically viewed as virtualized instances, but in recent years, some providers have begun offering both virtual and bare-metal cloud. Bare-metal servers are not virtualized and do not have a hypervisor, which allows organizations to customize the server to their specifications. Cloud computing operating systems such as OpenStack offer the ability to create and manage cloud instances from the same online management portal.
Common use cases for public cloud include web servers, testing and development, and other scenarios where enhanced security requirements are not needed.
Private cloud offers a single-tenant environment where hardware, network and IT equipment is entirely dedicated to one customer. While the initial investment and ongoing maintenance for private cloud is more expensive than public cloud, organizations have the ability to customize their environment to meet exact specifications.
A highly customized, dedicated environment is often required by businesses that must adhere to industry-wide security or compliance regulations, such as HIPAA, HITECH or PCI-DSS. To be compliant, many healthcare, finance and ecommerce companies are required to have an infrastructure with higher levels of data protection and security than a commodity public cloud can provide.
Private cloud hosting solutions give customers significant control over their environment, including the hardware, operating system and other equipment. However, increased customization and control also shifts the burden of maintenance and management to the customer. This is one of the main trade-offs between public and private cloud; organizations that require more hands-on access and customization must also take on the responsibility of managing it.
Common use cases for private cloud include secure online systems with controlled access, protection of personally identifiable information and credit card data, and meeting compliance requirements around HIPAA, HITECH or PCI-DSS.
A Hybrid Approach
Public cloud and private cloud are not mutually exclusive, and most businesses need to use a mix of different infrastructure solutions to meet workload and application requirements. Hybrid cloud solutions refer to any combination of public, private, third-party or on-premise cloud services within the same environment.
Using one provider that offers public, private and hybrid cloud can be a cost-effective way to meet scalability, performance and security requirements. If an organization is transferring data between a private cloud located in California and a public cloud facility in New York, the latency created by distance can impact network performance. Choosing a provider that offers private and public clouds in close proximity to each other or even within the same facility can reduce latency and improve performance throughout the infrastructure stack.