As a former Azure admin, I am familiar with cloud concepts from the perspective of a subject matter expert. However, I recently studied “the cloud” not just in my MBA program, but also during a review for the AWS and Azure foundational cloud certifications. These certifications cover their respective cloud platforms from a non-technical perspective. I thought it would be great to combine all of the different viewpoints into one blog post for posterity.
Let’s start with something simple. What is the cloud? From my original perspective, the “cloud” was always a datacenter, or warehouse of servers, that was made publicly available. People connecting remotely into this network of machines would be able to use its computational resources. This perspective covers most enterprise use-cases but isn’t fully correct. Amazon defines it even more simply; they refer to all clouds as “internet.” Private cloud, public cloud, hybrid cloud, all of them can otherwise be known as private internet, public internet, and hybrid internet. Describing clouds in this way makes much sense because all servers have to be on some network to communicate and do work. Immediately looking at all clouds as “internet” leads to a smoother transition to understanding other concepts such as an in-house network, virtual network, and why VPNs are helpful for hybrid environments.
Microsoft uses technical standards defined by global organizations to explain what a cloud is. These standards utilize specific measures such as availability, scalability, elasticity, agility, fault tolerance, and disaster recovery. I feel that this is the most formal way to look at cloud technology, but it makes sense given its standard-based backing. All of these viewpoints cover the same thing, just with new items included or certain things out of focus.
AWS and Azure
Both the AWS Certified Cloud Practitioner and Azure Fundamentals certifications cover similar material when it comes to cloud technology. Below are the test objectives for both exams that pertain to cloud concepts:
- Microsoft Azure: Understand cloud concepts (15-20%)
- Describe the benefits and considerations of using cloud services
- understand terms such as high availability, scalability, elasticity, agility, fault tolerance, and disaster recovery
- understand the principles of economies of scale
- understand the differences between Capital Expenditure (CapEx) and Operational Expenditure (OpEx)
- understand the consumption-based model
- Describe the differences between Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS)
- describe Infrastructure-as-a-Service (IaaS)
- describe Platform-as-a-Service (PaaS)
- describe Software-as-a-Service (SaaS)
- compare and contrast the three different service types
- Describe the differences between public, private and hybrid cloud models
- describe public cloud
- describe private cloud
- describe hybrid cloud
- compare and contrast the three different cloud models
- Describe the benefits and considerations of using cloud services
- AWS Domain 1: Cloud Concepts
- Define the AWS Cloud and its value proposition
- Identify aspects of AWS Cloud economics
- List the different cloud architecture design principles
Some common themes between the two exams are: explaining what the cloud is, how it helps companies and different cloud service designs.
Important Cloud Concepts
Benefits and Value Proposition
The primary value cloud technologies provide for companies is cost-savings. It is very expensive for companies to set up on-premises IT infrastructure, and on top of that, a lot of maintenance and on-going staffing costs as well. For many companies, these costs are so significant that even if they are approved initially, the subsequent requisition and purchasing processes take an exorbitant amount of time. By outsourcing the cost of IT infrastructure onto a cloud provider, companies can become much more agile and efficient. Both AWS and Azure offer features such as pay-as-you-go, resource reservation, and quick scaling-up or down to enable customers to make faster decisions. Both services also offer total cost of ownership (TCO) calculators, resource tagging, and automated advisors to help customers find ways to save money.
Both Microsoft and Amazon explain their cost savings in terms of CAPEX and variable operating expenditures. Or in other words, companies are trading away their initial upfront capital expenditures for smaller, more acceptable operating expenses over time.
Differences Between IaaS, SaaS, and PaaS
Both Amazon and Microsoft have the same definitions for the three main types of cloud services. They also both offer a variety of services to customers to fit into one of these three buckets.
- IaaS: Infrastructure as a service. This is when cloud providers allow customers to use virtual servers. This is core to any backend IT team. Once a virtual server is stood up, it can be used to run essential services such as databases, identity management, or even web applications. IT admins can remote into these virtual servers to configure the operating system, install software, and troubleshoot.
- PaaS: Platform as a service. This is is when a cloud provider makes web-based tools available for the creation and deployment of applications. These tools will have heavy integration to other areas of the cloud platform.
- SaaS: Software as a service. This is when a cloud provider makes a web application available for use via browser. Customers can re-configure the software but can’t touch any of the servers or operating systems underneath, they can only touch the software.
Both Microsoft and Amazon offer ways for large companies to transition their traditional IT infrastructure to the cloud. For newer, smaller companies, going directly to cloud and being 100% offloaded is a realistic option.
- On-Premises: when companies completely own all of their hardware and pay for the maintenance and upkeep of their information technology. These companies can still have a version of a “cloud” in that their entire network is secure and only accessible by company employees. This is also known as a “private cloud.”
- Hybrid: when companies own some hardware but offload some data into the cloud. Due to this nature, there is often a need to have some sort of connecting link between the company’s private network and the public network of the cloud provider. This is usually established with a gateway or VPN. This cloud architecture allows companies to slowly transition to the cloud, or to maintain certain sensitive data to remain on-premises.
- Cloud: this is when companies completely offload their IT infrastructure to a cloud service provider like AWS or Azure.