Architecting the Cloud: Design Decisions for Cloud Computing Service Models (SaaS, PaaS, and IaaS)

Chapter 5

Choosing the Right Cloud Service Model

It takes less time to do things right than to explain why you did it wrong.

—Henry Wadsworth Longfellow, poet

One misperception about cloud computing is that one cloud service model fits all. That is the equivalent of choosing one tool to build a house. Obviously, it takes many different tools to build a house because there are so many different components that make up the architecture of the house. There is a concrete foundation; infrastructure items like plumbing, electrical, and sewage; interior items like walls, floors, and windows; and external items like roofs, driveways, gutters, and so on. Each component has its own set of requirements and therefore requires a different collection of tools. Obviously, laying and paving the driveway requires much different tools and processes than installing the plumbing or tiling the floors. It is a no-brainer that building a house requires many different skills and many different tools, and each component of the construction of a house has its own characteristics within the architecture of the entire house.

Building enterprise-grade software in the cloud is no different. Just as a builder uses many different tools and skills to build a house, an enterprise should use different cloud services models within the enterprise. Some companies pick a single cloud provider like Amazon Web Services (AWS), which provides Infrastructure as a Service (IaaS) solutions, or Azure, a provider of Platform ...