The Cloud Computing Platform

Cloud computing platforms vary:

Software as a Service (SaaS). In the SaaS layer, the service provider hosts the software so you don’t need to install it, manage it, or buy hardware for it. All you have to do is connect and use it. Examples include customer relationship management as a service.

Platform as a Service (PaaS). The PaaS layer offers black-box services with which developers can build applications on top of the computer infrastructure. This might include developer tools that are offered as a service, providing build, data access and deployment features.

Infrastructure as a Service (IaaS). The IaaS layer offers storage and computer resources that developers and IT organizations can use to deliver business solutions.

Deploying Public, Private, or Hybrid Clouds

Cloud computing happens on a public, private or hybrid cloud. Governance and security are crucial whether the cloud is in your company’s firewall or not.

Public clouds are virtualized data centres outside of your company’s firewall. Generally, a service provider makes resources available on demand, over the public Internet.

Private clouds are virtualized cloud data centres inside your company’s firewall. It may also be a private space dedicated to your company within a cloud provider’s data centre.

Hybrid clouds combine aspects of both public and private clouds.

Cloud Computing Characteristics

Whether your cloud is public, private, or hybrid, when looking for a cloud provider you need to consider elasticity, scalability, provisioning, standardization, and billed usage:

Elasticity and Scalability.
The cloud is elastic, meaning that resource allocation can get bigger or smaller depending on demand. Elasticity enables scalability, which means that the cloud can scale upward for peak demand and downward for lighter demand. Scalability also means that an application can scale when adding users and when application requirements change.

Self-Service provisioning.
Cloud customers can provision cloud services without going through a lengthy process. You request an amount of computing, storage, software and/or process from the service provider. After you use these resources, they can be automatically de-provisioned.

Standardized Interfaces.
Cloud services should have standardized APIs, which provide instructions on how two application or data sources can communicate with each other. A standardized interface lets the customer more easily link cloud services together.

Billing and Service Usage Metering.
You can be billed for resources as you use them. This pay-as-you-go model means usage is metered and you pay only for what you consume.