AWS SAA 2020

Question 1

AWS Regions

Answer 1

• Regions are spread all around the world
• Regions consists of multiple Availability Zones
• Most AWS Services are region scoped
• As of May 2020, AWS has 24 regions around the world, with 3 new regions coming soon in Spain, Jakarta and Osaka (Japan)

Question 2

Availability Zones

Answer 2

• Each region has multiple Availability Zones
• Usually 3, Min 2, Max 6 Availability Zones per region
• Each AZ is an independent data center, with redundant power supply, network and connectivity to reduce the likelihood of two zones failing simultaneously
• Since each AZ is distinct and geographically isolated from other, they are isolated from disasters
• Breakdown of any single AZ doesn’t impact other AZs in the same region. That means, the services in a region are still available even if one of the AZ in that region is down.
• A common misconception is that a single zone equals a single data center. In fact, each zone is backed by one or more physical data centers, with the largest backed by five.
• While a single AZ can span multiple data centers, no two AZ share a data center. Abstracting things further, to distribute resources evenly across the zones in a given region, Amazon independently maps AZs to identifiers for each account. This means the us-east-1a AZ for one account may not be backed by the same data centers as us-east-1a for another account.
• As if May 2020, there are 76 Availability Zones present all over the world.
• By launching your nodes (EC2, ElastiCache) in different AZs you are able to achieve the greatest possible fault tolerance.