CLOUD / A CONCEPT NOTE
Regions & AZs
where your stuff physically is
Overview · mechanism
pitfall · examples
01 / THE SHORT VERSION
The idea in a few sentences.
A Region is a geographic area (like us-east-1). An Availability Zone (AZ) is a distinct physical datacenter inside that region, connected via low-latency fibers.
02 / FOLLOW THE MECHANISM
How redundancy routing flows
User query
lands on the load balancer, which distributes traffic across three datacenters.
Replication
database updates are synced across AZs to guarantee high availability.
Disaster event
a physical fire cuts power to AZ-A.
Failover
load balancer routes traffic away from AZ-A to AZ-B and AZ-C without downtime.
04 / COMMAND NOTES
Read the command, then the result.
Inspect the flags and arguments before trying an example. Snippets can need local setup, replacement values, or resources in your own environment.
list all availability zones in a region
aws ec2 describe-availability-zones --region us-east-105 / CHECK YOURSELF
Could you explain Regions & AZs to a teammate?
Try it out loud in two sentences: what it is, and the one detail that changes the picture. If you stall, the gap is the part to reread.
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