3: Cloud Computing Fundamentals


  1. NIST Cloud definition

Cloud Computing - What is it really?

The formal definition with 5 characteristics by NIST:

  1. On-Demand Self-Service: Can provision capabilities as needed without requiring human interaction.
  2. Board Network Access: Capabilities are available over the network and accessed through standard mechanisms.
  3. Resource Pooling: There is a sense of location independence ... no control or knowledge over the exact location of resources. Resources are pooled to serve multiple consumers usig a multi-tenant model.
  4. Rapid Elasticity: Capabilities can be elastically provisioned and released to scale rapidly outwarn and inward with demand. To the consumer, the capabilities available for provisioning often appear the be unlimited.
  5. Measured Service: Resource usage ca be monitored, controlled, reported and billed.

Understanding these five will make sure the answer that the architecture uses makes sense.

Public vs Private vs Hybrid vs Multi-Cloud

  1. Public Cloud: Available to public vendors. All the major cloud platforms are public cloud as it classifies as a cloud environment that is available to the public.
  2. Multi-Cloud: Using multiple Cloud platforms.
  3. Private Cloud: All major cloud platforms provide an option to provide on-prem cloud. Private cloud is a platform that fits the classification of a cloud and is available to your business. tl;dr using on-prem "real" cloud.
  4. Hybrid Cloud: Sharing public cloud and private cloud.

Note: there is a difference between hybrid cloud and hybrid environment.

Cloud Service Models

If you ever see the term XaaS it is generally a cloud service model.

Some common terms:

  • Infrastructure Stack: collection of things the app needs stacked on top of each other.
  • Infrastructure stack has parts that you manage and parts managed by the vendor (at least for cloud).
  • Unit of consumption: your responsibility that you manage as part of the stack.

Examples of unit of consumption:

  • On-Prem: Everything on the stack.
  • DC (data center) Hosted: Unit of consumption was the rack space.
  • Infrastructure-as-a-Service: Your unit of consumption is the O/S.
  • Platform-as-a-Service: You consume the runtime environment.
  • Software-as-a-Service: You pay and consume the app.