Creating 3-Tier Architecture Using AWS

This diagram represents a typical three-tier architecture implemented in AWS. It includes the Web Tier, App Tier, and Database Tier, each with various AWS services. Let me break down the components:

1. VPC (Virtual Private Cloud) The entire architecture is hosted in a VPC, which provides an isolated network environment.
2. Subnets Public Subnets (Web Tier): These subnets are accessible from the internet and host the web servers. Private Subnets (App Tier and Database Tier): These are not directly accessible from the internet, providing added security for the application and database layers.
3. Internet Gateway Connects the VPC to the internet, allowing resources in the public subnet to send/receive traffic.
4. Elastic Load Balancer (ELB) Distributes incoming traffic across multiple Amazon EC2 instances in the Web Tier, ensuring high availability and fault tolerance.
5. Amazon EC2 Instances Web Tier (Public Subnet): Hosts web servers that handle incoming HTTP/HTTPS requests from users. App Tier (Private Subnet): Hosts application servers where the core business logic and API processing happen.
6. Amazon Aurora (Database Tier) Aurora Primary DB: A managed relational database service optimized for performance and availability. Aurora Read Replica: Used for load balancing read-heavy database workloads, improving performance and scalability.
7. Security Communication between tiers occurs over private subnets, enhancing security. The use of private subnets ensures that sensitive resources (like databases) are not exposed to the internet.
8. Multi-AZ Deployment The architecture is deployed across two Availability Zones (AZ1 and AZ2) for high availability and disaster recovery.

Flow of Traffic:

1. Internet Gateway allows traffic to the public subnet.
2. Elastic Load Balancer routes requests to web servers in the Web Tier.
3. Web servers in the Web Tier communicate with application servers in the App Tier (private subnets).
4. Application servers interact with the Aurora Database in the Database Tier for data storage/retrieval.
5. This design ensures scalability, fault tolerance, and security, adhering to AWS best practices for a three-tier architecture.

PART - 0
Step 1: Create S3 bucket
Step 2: Create IAM User
Give permission for AmazonS3ReadOnlyAccess, AmazonSSMManagedInstanceCore to the IAM role