Cloud Concepts
What you will learn
In this domain, you will learn what cloud computing is, how it differs from on-premises infrastructure, how the elements of the AWS global infrastructure (Regions, Availability Zones, and edge locations) relate to one another, and the six advantages the cloud provides. It is a fundamental and important domain that accounts for roughly a quarter of the CLF-C02 exam.
Key points
- Cloud computing is a model in which you consume IT resources over the internet, paying only for what you use
- The six advantages of the cloud - no upfront investment, economies of scale, no need to guess capacity, agility, focus on operational spending, and easy global deployment
- A Region is a geographically isolated AWS location, while an Availability Zone (AZ) is a group of physically separated data centers within a Region
- Edge locations are distributed points used for content delivery, such as CloudFront, that reduce latency by serving content from a place close to the user
- Distinguish between scalability (the ability to increase or decrease capacity) and elasticity (the ability to automatically follow changes in demand)
- High availability is the property of being resistant to downtime, while fault tolerance is the property of continuing to process work even when a failure occurs
Terms and concepts
Cloud Computing
A model for consuming IT resources (servers, storage, databases, and so on) over the internet on a pay-as-you-go basis. You do not need to own and operate physical hardware yourself, and you can use exactly as much as you need, when you need it.
Elasticity
The ability to automatically scale resources up and down in response to changes in demand. You do not have to reserve maximum capacity in advance for short-term traffic spikes, such as a sale on an e-commerce site, and can instead provision exactly what you need dynamically.
Regions and Availability Zones
A Region is a geographically isolated AWS location, and each Region has three or more Availability Zones (AZs). An AZ is a group of physically separated data centers, and spanning your architecture across AZs prevents a failure in one location from taking everything down.
→ Fault Isolation Design with AZs ・ → The Strengths of Regions and Edge Locations
Edge Locations
Points distributed around the world that are used by content delivery networks (CDNs) such as CloudFront. By caching content in a location physically close to the user, they improve display speed and reduce the load on origin servers.
→ How CloudFront Chooses Its Routes ・ → Amazon CloudFront (Glossary)
The Difference Between High Availability and Fault Tolerance
High availability (HA) means that the service is down for only a short amount of time, while fault tolerance (FT) means that the service can continue running even while a failure is occurring. For example, a Multi-AZ RDS deployment provides HA, whereas a configuration that writes to multiple AZs in real time moves closer to FT.
Check your understanding
Check what you have learned with 5 questions