Databases in AWS – RDS, DynamoDB, Aurora

Scalable, Reliable, and Managed Database Services for Every Application

Databases are a core building block of modern applications, and AWS offers fully managed services to support relational, non-relational, and hybrid database workloads. This chapter explores the key AWS database offerings, focusing on Amazon RDS, Amazon DynamoDB, and Amazon Aurora.

🧱 AWS Database Service Landscape

📌 In this chapter, we’ll focus on RDS, Aurora, and DynamoDB, the three most used options for developers and businesses.

Section 1: Amazon RDS (Relational Database Service)

🔍 What is RDS?

Amazon RDS is a managed service that makes it easy to set up, operate, and scale relational databases in the cloud.

Supported Engines:

• MySQL
• PostgreSQL
• MariaDB
• Oracle
• SQL Server

✅ AWS handles backups, patching, monitoring, scaling, and replication.

⚙️ RDS Architecture Options

Creating RDS Instance (Console)

1. Go to RDS → Create database
2. Choose Standard Create
3. Engine: e.g., PostgreSQL
4. DB instance class: e.g., db.t3.micro
5. Multi-AZ deployment: Enable for production
6. Set master credentials
7. Storage: 20 GB GP2
8. Enable backups, monitoring
9. Launch

✅ Security & Access

• Place RDS in private subnet
• Use security groups to allow access only from app instances
• Never expose RDS to public internet
• Enable IAM DB authentication for MySQL and PostgreSQL
• Use SSL for connections

📊 RDS Pricing Tips

• Use burstable instances (db.t3) for dev/test
• Enable storage auto-scaling
• Disable Multi-AZ for non-critical workloads
• Use Reserved Instances for long-term production use (up to 70% off)

Section 2: Amazon Aurora – Cloud-Native Relational Database

🔍 What is Amazon Aurora?

Amazon Aurora is a MySQL- and PostgreSQL-compatible relational database built for the cloud.

• Up to 5x faster than MySQL, 3x faster than PostgreSQL
• Auto-healing, multi-AZ replication, and serverless option
• Storage autoscaling from 10 GB up to 128 TB

🚀 Aurora Key Features

Aurora vs RDS

Aurora Use Cases

• Large-scale web applications
• SaaS platforms with bursty traffic
• Global apps needing read/write performance
• Financial services requiring instant failover

Section 3: Amazon DynamoDB – NoSQL at Any Scale

🔍 What is DynamoDB?

Amazon DynamoDB is a fully managed NoSQL database that offers single-digit millisecond latency at any scale.

• No servers to manage
• Automatically scales based on traffic
• Supports key-value and document data models
• Built-in replication, encryption, and TTL (Time To Live)

🧱 Core DynamoDB Concepts

✅ When to Use DynamoDB

• High-velocity applications (gaming, IoT, mobile)
• Shopping carts, session stores
• Serverless APIs with low-latency needs
• Multi-region applications

DynamoDB Example (AWS CLI)

Create Table:

aws dynamodb create-table \
  --table-name Products \
  --attribute-definitions AttributeName=ProductID,AttributeType=S \
  --key-schema AttributeName=ProductID,KeyType=HASH \
  --billing-mode PAY_PER_REQUEST

aws dynamodb create-table \
  --table-name Products \
  --attribute-definitions AttributeName=ProductID,AttributeType=S \
  --key-schema AttributeName=ProductID,KeyType=HASH \
  --billing-mode PAY_PER_REQUEST

Put Item:

aws dynamodb put-item \
  --table-name Products \
  --item '{"ProductID": {"S": "1001"}, "Name": {"S": "Mouse"}}'

aws dynamodb put-item \
  --table-name Products \
  --item '{"ProductID": {"S": "1001"}, "Name": {"S": "Mouse"}}'

DynamoDB Features

Summary Table: RDS vs Aurora vs DynamoDB