AWS Architecture 101 Flashcards
What are the characteristics of AWS accounts, with regards to Authentication, Authorisation and Billing
o AWS accounts are isolated: they are initially created with a single root user, which is the only identity that can be used to authenticate to the account
o Authorisation is controlled on a per-account basis. The root user starts with full control over the account and its resources; additional entities can be created and granted access
o Accounts can be linked and configured to allow consolidated billing, where a master account is billed for all its member accounts resource usage
How is AWS Global Infrastructure structured?
o Regions: Local grouping of infrastructure. Services are (usually) delivered from a Region. 21 existing Regions. Regions are Isolated and they isolate data to a specific Country. Examples of Regions are us-east-1 (US East, North Virginia). Regions are used to ensure content is as close to customers as possible
o Availability Zones: Regions are broken down into Availability Zones, represented by letters (us-east-1 => 1a, 1b, 1c). AZ provide isolated infrastructures within a Region: a failure in one AZ won’t impact another AZ in the same Region. AZs are connected with high speed networks, so products and services can communicate between AZs
o Edge Locations (or Points of Presence) are small pockets of AWS infrastructure closed to major populations, generally used for edge computing and content delivery
What are the 5 Pillars of the Well Architected Framework?
o Security, Reliability, Performance Efficiency, Operational Excellence and Cost Optimisation
What is the difference between Scalability and Elasticity?
o Vertical Scaling: based on trying to forecast demand and purchase servers, before demand exceeds current capacity. Purchase early and capacity is wasted, purchase late and performance is impacted
o Horizontal Scaling: capacity can be maintained closer to demand, thanks to more, smaller servers
o Elasticity: also known as Elastic Capacity, is where automation and horizontal scaling are used in conjuction to match capacity with demand. More aligned to real life demand, which follows peaks and valleys, allowing to scale out and in
