Day 9: Introduction to AWS — Global Infrastructure, Regions & Availability Zones

#regions #availabilityzone #aws #cloud

Moving into AWS now. Today: what AWS actually is, and how its global infrastructure — Regions, Availability Zones, and Local Zones — is structured.

What is AWS?

AWS (Amazon Web Services) is a secure cloud service platform that offers compute power, database, storage, content delivery, and other resources to help businesses scale and grow.

Provides 175+ services
Client security is a major focus — AWS's infrastructure successfully satisfies the security needs of military, global banks, and other high-sensitivity organizations
Has 230+ security, compliance, and governance services, with 90+ security standards and compliance certifications, and 117+ AWS services can encrypt data

Benefits of AWS

Easy to use
Scalable, with high performance
Dominant market position
Cost effective
Reliable
Secure
Flexible
Can support large organizations

AWS Global Infrastructure

Regions

A Region is a separate geographic area containing a set of Availability Zones — e.g., AWS Region = Mumbai
AWS currently has 34 Regions
Regions don't communicate with each other by default (only if required/configured)
Choosing the right region depends on: pricing, user/customer location, latency, service availability, and security/compliance requirements

Availability Zones (AZs)

An Availability Zone is a data center (or group of data centers) within a Region
A Region contains multiple AZs
Each AZ has an independent power supply, cooling system, and physical security
Each AZ is connected to other AZs in the same Region via a redundant, low-latency network
AZs make applications and databases highly available, fault-tolerant, and scalable compared to traditional data centers
Best practice: distribute instances across AZs — very unlikely that more than one AZ goes down at once
Data can be shared across AZs if required
An EC2 instance is specific to a Region and AZ — e.g., if you launch an EC2 instance in Mumbai, it stays in Mumbai unless you explicitly launch in another region like Ireland

Local Zones

An AWS infrastructure deployment option that places AWS compute, storage, database, and other services closer to large population centers and industry hubs where no AWS Region exists today
Used to deploy workloads requiring single-digit millisecond latency, like video rendering and virtual desktop applications

Direct Connect

Lets organizations establish private connections between AWS and their datacenter, office, or colocation environment
Results in reduced network costs, increased bandwidth, and a more consistent network experience than internet-based connections

Latency

Latency is the measure of time required for data to transfer from client to server and back
The higher the latency, the lower the efficiency
AWS has clients throughout the world, so to reduce latency and avoid overloading servers, they use Edge Locations
Low latency = good (fast); High latency = bad (slow)
Always choose the region closest to your customer's location for the best latency

POP (Points of Presence) Locations

Small setups in different locations where AWS caches content and delivers it quickly to the end user
As of a recent count, AWS provides 217+ Points of Presence (205 Edge Locations and 12 Regional Edge Caches)
POP locations are used by Amazon CloudFront (AWS's CDN service) — a fast content delivery network that securely delivers data, videos, and applications to customers globally with low latency
We can cache data to the POP location nearest the end-user using CloudFront
If you use AWS origins such as Amazon S3, Amazon EC2, you don't pay for any data transferred from your origin to CloudFront Edge Locations

Data Replication Between Regions

Data present in one region can be replicated to a different region to maintain data availability during failure.

Benefits of data replication:

Increases fault tolerance
Increases redundancy
Reduces latency

Availability — the Core Idea

Availability refers to the ability of a system or component to be operational and accessible anytime. It ensures that data and services are available in normal and even disaster recovery operations — it always answers the question "Can I access my data right now?" This is achieved by maintaining reliable engineering, redundancy, and management techniques that minimize system failures and time to repair.