Global Infrastructure

Is an application deployed in multiple geographies.
On AWS this could be Regions or Edge Locations.
Why?
- Decreased latency: time it takes for a network packet to reach a server.
- Disaster recovery: if a AWS region goes down you can fail-over to another region.
- Attack protection: distributed global infrastructure is harder to attack.
In AWS
- Global DNS: To route users to the closest deployment with least latency and good for disaster recovery strategies.
- Global Content Delivery Network (CDN): Replicate part of your application to AWS edge locations to decrease latency and cache common requests.
- S3 Transfer Acceleration: Accelerate global uploads & downloads into Amazon S3.
- AWS Global Accelerator: Improve global application availability and performance using AWS global network.

Regions: for deploying applications and infrastructure.
Availability Zones (AZ): Made of multiple data centers.
Edge locations (points of presence): for content delivery as close as possible to users.

Is a managed DNS (Domain Name System).
DNS is a collection of rules and records which helps clients understand how to reach a server through URLs.
Features Available:
- Domain registration.
- DNS.
- Health checks.
- Routing policy.
Common records in AWS:
- www.google.com -> 12.34.56.78 == A record (IPv4).
- www.google.com -> 2001:0db8:85a3:0000:0000:8a2e:0370:7334 == AAAA IPv6
- search.google.com -> www.google.com == CNAME:hostname to hostname
- example.com -> AWS resource == Alias (ex: ELB, CloudFront, S3, RDS, etc.)
Routing Policies
- Simple Routing Policy: no health checks.
- Weighted Routing Policy: distribute the traffic across EC2 instances by giving a weight to each of our instances. (think of load balancing)
- Latency Routing Policy: Will allocate users to talk to the closest server to minimise latency.
- Failover Routing Policy: Great for disaster recovery, if the main has failed. It will be redirected to the failover.

Is a Content Delivery Network.
Improves read performance, content is cached at the edge locations.
216 Points of Presence globally (edge locations).
DDoS protection, integration with Shield, AWS Web Application Firewall (WAF).
CloudFront - Origins
- S3 Bucket:
  - For distributing files and caching them at the edge.
  - Enhancing security with CloudFront Origin Access Control (OAC).
  - CloudFront can be used as an ingress (to upload files to S3).
- Custom Origin (HTTP):
  - Application Load Balancer.
  - EC2 Instance.
  - S3 Website (must first enable the bucket as a static S3 site).
  - Any HTTP backend you want.
vs S3 Cross Region Replication
- CloudFront is great for static content that must be available everywhere.
- S3 Cross Region Replication is great for dynamic content that needs to be available at low-latency in few regions.
S3 Transfer Acceleration
- Increase transfer speed by transferring file to an AWS edge location which will forward the data to the S3 bucket in the target region.
- This works because the user upload to an edge location which is close.
- Then the edge location can transfer to the S3 bucket through AWS internal network which is also fast.

Improve global application availability and performance using the AWS global network.
Leverage the AWS internal network to optimise the route to your application.
2 Anycast IP are created for your application and traffic is sent through edge locations.
The edge locations send the traffic to your application.
vs CloudFront
- They both use AWS global network and its edge locations around the world.
- Both integrate with AWS Shield for DDoS protection.
- CloudFront - CDN improves performance for your cacheable content and content is served at the edge.
- Global accelerator has no caching, it proxies packets at the edge to applications running in one or more AWS regions.
  - It improves performance for a wide range of applications over TCP or UDP.
  - Good for HTTP use cases that require static IP addresses and that required deterministic, fast regional failover.

Hybrid Cloud: businesses that keep an on-premises infrastructure alongside a cloud infrastructure.
2 ways of dealing with IT systems.
- One for the AWS cloud.
- One for the on-premises infrastructure.
AWS outposts are server racks that offer the same AWS infrastructure, services and you can start leveraging AWS services on premises.
AWS sets up and manages the Outpost racks.
You are responsible for the Outposts rack's physical security.
Benefits
- Low latency access to on-premises systems.
- Local data processing.
- Data residency.
- Easier migration from on-premises to the cloud.
- Fully managed service.

WaveLength Zones are infrastructure deployments embedded within the telecommunications provider's data centers at the edge of 5G networks.
Brings AWS services to the edge of the 5G networks.
Ultra-low latency applications through 5G networks.
Traffic doesn't leave the Communication Service Provider's (CSP) network.
High-bandwidth and secure connection to the parent AWS region.
No additional charges or service agreements.
Use Cases: Smart cities, ML-assisted diagnostics, connected vehicles, interactive live video streams, real-time gaming, etc.

Places AWS compute. storage, database and other selected AWS services closer to end users to run latency-sensitive applications.
Extend your VPC to more locations.
Example:
- AWS Region: N.Virginia (us-east-1).
- AWS Local Zones: Boston, Chicago, Dallas, Houston, Miami...

Single Region, Single AZ: Low Availability, High global latency, easy difficulty to create.
Single Region, Multi AZ: High Availability, High global latency, medium difficulty to create.
Multi Region, Active-Passive: Low Global Reads latency, High Global Writes latency, medium difficulty to create.
Multi Region, Active-Active: Low Global Reads latency, Low Global Writes latency, hard difficulty to create.

Global DNS: Route 53
- Great to route users to the closest deployment with least latency
- Great for disaster recovery strategies
Global Content Delivery Network (CDN): CloudFront
- Replicate part of your application to AWS Edge Locations – decrease latency
- Cache common requests – improved user experience and decreased latency
S3 Transfer Acceleration
- Accelerate global uploads & downloads into Amazon S3
AWS Global Accelerator
- Improve global application availability and performance using the AWS global network- Global DNS: Route 53.
AWS Outposts
- Deploy Outposts Racks in your own Data Centers to extend AWS services
AWS WaveLength
- Brings AWS services to the edge of the 5G networks
- Ultra-low latency applications
AWS Local Zones
- Bring AWS resources (compute, database, storage, …) closer to your users
- Good for latency-sensitive applications