Cloud Computing Foundations · Study deck
Cloud Platforms: Open-Source and Commercial
Every chapter so far in this module has stayed at the level of a model or a taxonomy -- NIST's definition, the service-model responsibility bracket, the deployment-model taxonomy, the economics of scaling.
Cloud Clara is your guide for this deck.

After studying this chapter
Learning objectives
You will be able to:
- Compare open-source and commercial cloud platforms by ownership, service breadth, and who implements security
- Name OpenStack's core components and what each one manages, without installing a live stack
- Evaluate a named cloud product, version, or instance family for currency instead of memorizing today's catalog
- Explain what CloudSim and CloudAnalyst simulate, and why a simulated placement decision still needs a real pilot
Major section
Open-Source and Commercial Clouds, and OpenStack's Architecture
With that energy-simulation angle in view, the first taxonomy this chapter needs is not a service model or a deployment model -- it is ownership.
- Shared: provider secures infrastructure; customer duties vary across IaaS, PaaS, and SaaS.
- Reading the table's own logic rather than its specific names, neither platform category makes security a one-party task.
- With a self-hosted open-source cloud, the organization operating the platform must secure the physical and virtual infrastructure, while each tenant still governs identity, configuration, workloads, and data.
Major section
Commercial Platforms: Reading Azure and EC2 as Examples, Not as a Catalog
Microsoft Azure -- previously named Windows Azure -- is this chapter's named example of a commercial platform spanning both PaaS and IaaS.
- The transferable skill is recognizing the shape ("a provider groups dozens of individual services into a handful of named categories so a customer can navigate them") rather than memorizing this particular ten-item list.
- A platform is provided to clients to develop and deploy software; clients focus on application development rather than hardware and infrastructure.
- Named fit: applications where complete control is required, and workloads that need custom configurations loaded onto the infrastructure.
Major section
Commercial Platforms: Reading Azure and EC2 as Examples, Not as a Catalog (continued)
Rule-based or schedule-based automated scaling; separate availability zones within data centers increase fault tolerance.
- An Elastic IP maps a fixed address onto any of a user's virtual machines; instances gain enhanced security through public-private key pairs.
- Amazon CloudWatch monitors CPU, disk, and network resource utilization; Virtual Private Clouds (VPCs) are logically separated from the rest of the AWS cloud, with an optional connection back to a user's own network.
- The instance-family names in the box above are the part of EC2 most likely to have changed since this material was recorded.
Major section
Under the Hood: OpenStack's Components, Devstack (Conceptually), and Testing Placement Decisions in Simulation
The source material's own version list runs Austin, Bexar, Cactus, Diablo, Essex, Folsom, Grizzly, Havana, Icehouse, Juno, Kilo, Liberty, Mitaka, Newton, naming Ocata as "(Latest).".
- Naming "the current OpenStack release" here would just replace one dated fact with another that goes stale on the same clock.
- Where instances are actually launched and run.
- Lets the other services communicate with each other and lets a user build their own network.
Try it: Under the Hood: OpenStack's Components, Devstack (Conceptually), and Testing Placement Decisions in Simulation in the chapter
Deck summary
Key takeaways
With that energy-simulation angle in view, the first taxonomy this chapter needs is not a service model or a deployment model -- it is ownership.
- Microsoft Azure -- previously named Windows Azure -- is this chapter's named example of a commercial platform spanning both PaaS and IaaS.
- Rule-based or schedule-based automated scaling; separate availability zones within data centers increase fault tolerance.
- The source material's own version list runs Austin, Bexar, Cactus, Diablo, Essex, Folsom, Grizzly, Havana, Icehouse, Juno, Kilo, Liberty, Mitaka, Newton, naming Ocata as "(Latest).".
Retrieval practice
Recall check 1 of 3

Cloud Clara says: answer from memory, then check your reasoning.
Q1A small research group wants to self-host a cloud on hardware it already owns and is prepared to operate and secure that infrastructure while retaining the usual tenant duties for identity, configuration, workloads, and data. Which category, and which of the table's own named examples, fits best?
Show answer
Answer: A The open-source-vs-commercial table distinguishes self-operated software from subscribed services, not secure from insecure or customer security from provider security.
Retrieval practice
Recall check 2 of 3

Cloud Clara says: answer from memory, then check your reasoning.
Q2A colleague cites an old tutorial that lists "M4" as "the current AWS general-purpose instance family" and wants to provision M4 instances for a new project today. Per this chapter's own framing, what is the correct way to handle that claim?
Show answer
Answer: A Instance-family names are a dated snapshot; the durable fact is the category and AWS's own iteration pattern (letter for category, incrementing generation number), not any specific family name.
Retrieval practice
Recall check 3 of 3

Cloud Clara says: answer from memory, then check your reasoning.
Q3A student wants to know which named OpenStack component to check to find out what virtual-machine images are available to boot a new instance from, and which separate component actually launches that instance once chosen. Which two components are these, in that order?
Show answer
Answer: A OpenStack splits image management (Glance) and compute/launch (Nova) into two separate named components, each with one specific job -- part of why the nine-component architecture is worth learning as a shape rather than a single monolithic tool.
Print reference
Answers 1 of 2
Answer key.
- A · The open-source-vs-commercial table distinguishes self-operated software from subscribed services, not secure from insecure or customer security from provider security.
- A · Instance-family names are a dated snapshot; the durable fact is the category and AWS's own iteration pattern (letter for category, incrementing generation number), not any specific family name.
Print reference
Answers 2 of 2
Answer key.
- A · OpenStack splits image management (Glance) and compute/launch (Nova) into two separate named components, each with one specific job -- part of why the nine-component architecture is worth learning as a shape rather than a single monolithic tool.