Deploying Three Tier Architecture In Aws[cloud]
Table of Contents
Introduction
What is a Three-Tier Architecture?
Why Use Three-Tier Architecture in AWS?
Basic Terminologies in AWS
Virtual Private Cloud (VPC)
Subnets (Public & Private)
Internet Gateway & NAT Gateway
Elastic Load Balancer (ELB)
Amazon EC2 (Elastic Compute Cloud)
Amazon RDS (Relational Database Service)
AWS Auto Scaling
AWS IAM (Identity & Access Management)
AWS CloudWatch
Architecture Overview
Components of Three-Tier Architecture
AWS Services Used in Three-Tier Deployment
Step-by-Step Deployment of Three-Tier Architecture in AWS
Step 1: Setting Up the VPC and Networking
Step 2: Deploying the Presentation Layer (Frontend)
Step 3: Deploying the Application Layer (Backend)
Step 4: Deploying the Database Layer
Step 5: Implementing Security Best Practices
Step 6: Monitoring and Scaling
Conclusion
1. Introduction
What is a Three-Tier Architecture?
A three-tier architecture is a software design pattern that organizes an application into three distinct layers. Each layer serves a specific purpose, ensuring better scalability, security, and maintainability. The layers include:
Presentation Layer (Frontend) – The user interface (UI) that allows users to interact with the application.
Application Layer (Backend) – The core logic of the application that processes user requests and executes business logic.
Database Layer – A structured data storage system that maintains the integrity and consistency of the application's data.
Why Use Three-Tier Architecture in AWS?
A three-tier architecture in AWS offers several advantages:
Scalability: Each layer can scale independently based on demand, ensuring optimal resource utilization.
Security: The separation of layers reduces the attack surface and allows for better access control.
High Availability: AWS services like Auto Scaling and Elastic Load Balancing provide fault tolerance and prevent downtime.
Performance Optimization: By dividing responsibilities, each layer can be fine-tuned for better performance.
2. Basic Terminologies in AWS
Before deploying a three-tier architecture, it’s essential to understand key AWS components that play a crucial role in building this infrastructure:
Virtual Private Cloud (VPC)
A VPC (Virtual Private Cloud) is an isolated network environment within AWS where you can launch resources securely. It acts as a private data center, allowing you to control networking configurations such as IP ranges, security groups, and routing.
Subnets (Public & Private)
AWS subnets are subdivisions of a VPC that help segment network resources:
Public Subnet: This subnet allows direct communication with the internet and is used for hosting web servers and load balancers.
Private Subnet: Resources inside this subnet do not have direct internet access, making it ideal for application servers and databases.
Internet Gateway & NAT Gateway
Internet Gateway (IGW): Enables public-facing resources to communicate with the internet.
NAT Gateway: Allows resources in private subnets to access the internet while preventing inbound connections from external sources.
Elastic Load Balancer (ELB)
AWS ELB distributes incoming traffic across multiple EC2 instances to ensure application availability and fault tolerance.
Amazon EC2 (Elastic Compute Cloud)
EC2 provides virtual machines on demand, which can be used to host web applications, process backend logic, and store data.
Amazon RDS (Relational Database Service)
A fully managed database service that supports MySQL, PostgreSQL, and Amazon Aurora for storing structured data.
AWS Auto Scaling
Automatically adjusts the number of running instances based on traffic and workload fluctuations.
AWS IAM (Identity & Access Management)
Manages permissions and access control for AWS resources, ensuring security best practices are followed.
AWS CloudWatch
A monitoring service that tracks application performance, logs, and alerts for potential issues.
3. Architecture Overview
Components of Three-Tier Architecture
Presentation Layer (Frontend)
This layer is responsible for user interactions and request handling.
It consists of a web server running on Amazon EC2 instances or Amazon S3 for static content delivery.
Application Layer (Backend)
The business logic is handled here, ensuring proper request processing.
It is hosted on EC2 instances within a private subnet and can be scaled using Auto Scaling Groups.
Database Layer
A managed relational database is used to store application data securely.
Amazon RDS is used to ensure automatic backups, failover, and performance optimization.
AWS Services Used in Three-Tier Deployment
| Layer | AWS Services |
| Presentation (Frontend) | Amazon S3, EC2, ELB, CloudFront |
| Application (Backend) | EC2, Lambda, Auto Scaling |
| Database | Amazon RDS, DynamoDB, Aurora |
4. Step-by-Step Deployment of Three-Tier Architecture in AWS
Step 1: Setting Up the VPC and Networking
To begin, you must create a VPC (Virtual Private Cloud) to host all AWS resources in an isolated environment.
Define a CIDR block (e.g.,
10.0.0.0/16) to allocate IP addresses within the network.Create three subnets within the VPC:
Public Subnet: To host the frontend web servers and load balancer.
Private Subnet: To host backend servers that handle the application logic.
Database Subnet: To store data securely, without direct internet access.
Attach an Internet Gateway to provide public access to the frontend subnet.
Set up a NAT Gateway in the public subnet so backend instances can access the internet for updates without exposing them to external threats.
Configure Route Tables to define how traffic flows between subnets.
Step 2: Deploying the Presentation Layer (Frontend)
The frontend layer is responsible for handling user requests and displaying content:
Launch EC2 instances in the public subnet and install a web server like Apache or Nginx.
Attach these instances to an Elastic Load Balancer (ELB) to distribute traffic evenly.
Configure Auto Scaling Groups to dynamically increase or decrease instances based on user demand.
Step 3: Deploying the Application Layer (Backend)
The application layer processes user requests and executes business logic:
Deploy backend EC2 instances in a private subnet to enhance security.
Configure a Security Group that only allows traffic from the frontend layer.
Attach an ELB Target Group to route requests efficiently between backend instances.
Enable Auto Scaling to adjust the number of instances automatically based on application load.
Step 4: Deploying the Database Layer
The database layer ensures secure and scalable data storage:
Launch an Amazon RDS instance in a private subnet to prevent public access.
Choose a database engine (e.g., MySQL, PostgreSQL, Amazon Aurora).
Configure Multi-AZ deployment for high availability and failover support.
Set up security policies to allow access only from the backend.
Step 5: Implementing Security Best Practices
Use IAM roles to restrict access.
Enable AWS Web Application Firewall (WAF) for protection.
Encrypt sensitive data at rest and in transit.
Disable direct public access to databases.
Step 6: Monitoring and Scaling
Use CloudWatch to monitor performance metrics.
Implement Auto Scaling for frontend and backend layers.
Use CloudTrail to log AWS resource changes.
5. Conclusion
By following these steps, can successfully deploy a three-tier architecture in AWS, ensuring scalability, security, and high availability.