Infrastructure-as-a-Service (IaaS) is the true foundation for cloud computing, and what most people think about when they hear "cloud": vast resource pools in globe-spanning data center environments, shared and consumed on-demand by companies of all sizes. Today, the lines between public and private clouds have blurred when it comes to infrastructure. Many providers offer highly secure closed-loop environments that resemble a private cloud, but with the multi-tenancy (sharing some resource pool elements with others) and elasticity of the public cloud. Other providers offer a more open consumption model, where you consume resources on-demand in the provider's environment on a simple pay-as-you-go model. Today, many organizations create a hybrid cloud – where workloads are distributed across both a public and private tier for execution to attain the best of both worlds.
- Test/Dev environments
- Anything that requires burst capacity
- Mature, stable line of business applications
In a purely public cloud environment the provider owns the infrastructure, and customers simply pay to consume that infrastructure as a service. Capital expenditures on hardware are replaced by operational expenditures on that service, creating potential economic advantage. There still may be software-related capital expense that you'll have to layer onto the infrastructure environment, depending on your application stack.
Elasticity: The hallmark of Infrastructure-as-a-Service is economic elasticity. IaaS allows you to burst capacity on-demand, then scale back to normal levels the next day—without having to do anything other than pay for extra usage charges. Many hybrid clouds use the public cloud tier specifically for burst-capacity, and the private cloud tier for their normal computing requirements.
Resilience: Most public cloud providers offer highly advanced redundancy with uptime guarantees. A hybrid cloud can leverage this redundancy when resources that require continuity are maintained in the public tier.
Control: You are giving up some elements of control to the provider—you have to select the type of compute resources and how the environment is run when you initially deploy. Accordingly, you are committing to a set of SLAs around uptime, availability, recovery, etc. upon signup with the provider. You still have control over the management of your resources and the provisioning requirements —you give the orders, and the provider carries them out. Some providers enable this through a single console, which makes the process more seamless than when a request must be called in for capacity/environment changes. Hybrid clouds retain strong elements of control for the private-tier, while utilizing the public tier where less controls are required.
Security: Public and hybrid cloud environments may complicate regulatory compliance and data security, compared to fully private cloud environments that enable greater security control and auditability. More providers are finding ways to balance security and regulatory requirements with the extreme flexibility and elasticity that Infrastructure-as-a-Service provides. While security continues to be an issue in the IaaS category, we believe improvements will continue that enhance overall security. For example, division of data across tiers or encryption and obfuscation of data models when stored in a public tier can help address this challenge.
Flexibility: In a public cloud, or in the public tier of a hybrid cloud, the hardware and gear are not dedicated solely to your organization, so some flexibility to customize the environment is lost. There are many providers that offer multiple options through co-location of existing legacy systems to help enable greater flexibility.
Management: Public clouds can shift a significant amount of traditional systems management work from internal resources to provider resources, allowing IT more time to focus on strategic objectives. A hybrid cloud architecture can place strategic business application processing in the private tier and the commodity based resources in the public tier to achieve improved IT flexibility and return.
Mobility: The technological capabilities are available to provide highly scalable and available mobile access to organizations, but it depends on how an IaaS deployment (public or hybrid) leverages their architecture to provide the required mobile access.
Our Cloud team can help you discern, design, and deliver the best cloud solutions for your business. For more information, click here or contact an Account Executive at 1-800-369-1047.