AWS Cloud Practitioner Essentials T3.4

AWS Database Services Overview

• AWS offers various database services for data storage, management, and analysis.
• Databases can be hosted on EC2 (self-managed) or fully managed by AWS.

Hosted vs. Managed Databases

• EC2 Hosted Databases: You manage the database installation, backups, scaling, patching, and updates on an Amazon EC2 instance. Suitable for custom configurations.
• AWS Managed Databases: AWS handles database maintenance, scaling, and backups. Your responsibility is the data and queries. Ideal for reduced operational overhead and scalability.

Relational Databases

• Relational databases store data in tables with predefined schemas, best for structured data and complex queries.

Amazon RDS (Relational Database Service)

• Fully managed relational database service.
• Supports MySQL, PostgreSQL, MariaDB, Oracle, SQL Server, and Amazon Aurora.
• Features automated backups, patching, multi-AZ deployments for high availability, and read replicas for scaling read capacity.
• Suitable for traditional web servers and enterprise applications.

Amazon Aurora

• High-performance, cost-effective relational database specifically for the cloud.
• Compatible with MySQL and PostgreSQL.
• Significantly faster than standard MySQL and PostgreSQL (up to 5x and 3x respectively).
• Offers automatic scaling and continuous backups.
• Ideal for cloud-native applications requiring high performance and scalability.

NoSQL Databases

• NoSQL databases handle unstructured or semi-structured data and are suited for flexible and scalable applications.

Amazon DynamoDB

• Fully managed NoSQL database for fast, predictable performance.
• Serverless architecture: automatic scaling based on demand.
• Supports key-value and document data models.
• High availability and low latency.
• Excellent for real-time applications, IoT, and mobile applications (e.g., gaming).

Amazon ElastiCache

• Fully managed in-memory NoSQL database.
• Supports Redis and Memcached engines.
• Extremely low-latency reads and writes making it great for caching frequently accessed data.

Memory-Based Databases

• Designed for extremely fast data access.

Amazon ElastiCache (Redis/Memcached)

• Use cases: real-time analytics, session data caching, game leaderboards.

Amazon MemoryDB for Redis

• Managed Redis-compatible database for high speed and durability.
• Offers durable storage with in-memory speed.
• Features high availability with multi-AZ support.
• Ideal for both caching and data persistence.

Database Migration Tools

• AWS provides tools for migrating databases from on-premises or other cloud environments to AWS.

AWS Database Migration Service (AWS DMS)

• Migrates databases to AWS with minimal downtime.
• Supports homogeneous (e.g., Oracle to RDS Oracle) and heterogeneous migrations (e.g., SQL Server to Aurora PostgreSQL).
• Suitable for migrating operational databases.

AWS Schema Conversion Tool (AWS SCT)

• Converts database schemas and code from one database engine to another.
• Automatically adapts schemas for heterogeneous migrations.
• Supports stored procedures, triggers, and functions.
• Suitable for converting schemas from on-premises to an AWS database.

Key Use Cases

• Relational Databases: RDS for standard, Aurora for high-performance cloud-native systems.
• NoSQL Databases: DynamoDB for scalable real-time applications, ElastiCache/MemoryDB for caching.
• Memory-Based Databases: MemoryDB for high-speed persistence.
• Database Migration: DMS for minimal downtime migration, SCT for converting schemas.

Summary comparison of services

• | Service | Database Type | Best for | Key Features |
• | ------------------- | ------------- | --------- |----------------|
• | Amazon RDS | Relational | Web apps, business apps | Multi-AZ, read replicas, managed backups |
• | Amazon Aurora | Relational | Cloud-native, high-performance | Faster than MySQL/PostgreSQL, continuous backups |
• | Amazon DynamoDB | NoSQL | Real-time applications, mobile, IoT | Serverless, low-latency |
• | Amazon ElastiCache | In-Memory NoSQL | Caching | Redis/Memcached, extremely low-latency |
• | Amazon MemoryDB | In-Memory NoSQL | Persistent, high-speed | Durable, Redis-compatible |

Key Takeaways

• Choose managed databases for reduced management (e.g., RDS).
• Use hosted databases on EC2 for full control.
• Select the appropriate service based on your specific application needs and requirements.
• Consider the performance, scalability, and operational burden of each service for optimal solution selection.