Comparing the cloud computing delivery models

From the last section, we can now define what the delivery models are. This section looks at the characteristics of each model in more detail to help you understand when you may choose one over the other.

Each delivery model has several characteristics. The most appropriate model is defined by how much you want (or need/have mandated) to control, secure, and manage your resources, for example, your apps, code, data, networks, security, and so on.

The deployment model defines what control you have over your cloud computing resources, for example, your apps, data, networks, security, and so on. It describes what resources you share or have dedicated for your organization’s use.

We use the terms multi-tenant and single-tenant to differentiate between models that share resources or have dedicated resources.

We could analogize this to a house versus a hotel; with a house, you have your private and dedicated front door, stairs, kitchen, TV/movie subscription service, and more, whereas with a hotel, you have a private room dedicated to you for your sole use, but you share a front door, stairs, kitchen/restaurant, TV/movie subscription service, and so on:

Figure 1.5 – Comparing cloud computing delivery models

Now that we have a basic understanding of the delivery models, this next section will cover the characteristics of each delivery model in more depth.

Characteristics of public cloud computing resources

To recap, a public cloud is a shared entity (multi-tenant) computing model.

The following are the characteristics of public cloud computing resources:

  • Metered pricing and consumption-based billing and pay-as-you-go monthly usage costs; you only pay for the resources you use, which can allow cost control and cost management.
  • Almost unlimited resources are available.
  • Performance, scalability, and elasticity. Rapid, on-demand, and automated provisioning and de-provisioning computing resources are required.
  • Availability, reliability, fault tolerance, and redundancy.
  • Computing resources access is available anywhere, typically via the internet and a private managed network such as Microsoft’s ExpressRoute service.
  • Self-service management, typically through a web browser or a command-line interface.
  • Least control over security, protection, and compliance; you do not have complete control over security and compliance with the public cloud model.
  • Access to computing resources can be provided by Azure Active Directory as the identity and authentication layer and traditional Windows Server Active Directory when you synchronize the directories.
  • Physical hardware is not/cannot be deployed to public cloud computing platforms; virtual servers are provided. However, some cloud providers allow physical hardware to be dedicated to an organization’s use.
  • May allow on-premises facilities hosting computing resources to be decommissioned.
  • Expenditure model; move from a CapEx model to an OpEx model. No CapEx on hardware.

The following giants are use case examples of public cloud platforms: Microsoft Azure, Amazon Web Services (AWS), and Google Cloud Platform (GCP).