Migrating applications with relational database backends (RDBMS) to AWS involves a critical decision: Use Amazon RDS or host a database server on an AWS EC2 instance. This datasheet provides a concise comparison to help you make an informed choice for your cloud migration strategy.
Amazon Relational Database Service (Amazon RDS) is a managed Database-as-a-Service (DBaaS) supporting popular database engines like MySQL, MariaDB, PostgreSQL, Oracle, and SQL Server. It simplifies database setup, operation, and scaling, offloading time-consuming administrative tasks to AWS.
Amazon Elastic Compute Cloud (EC2) provides secure, resizable compute capacity in the cloud. Users can provision EC2 instances and manually install the required database engines, offering complete control over the computing resources.
Managed Service: Automates provisioning, setup, patching, backup, recovery, and failure detection.
Backup and Recovery: Automatic daily backups with a 24-hour RTO; near-zero RPO with multi-region strategies.
Patching: Routine patches during maintenance windows.
Read Replicas: Improve read capacity and reduce IOPS by routing read queries to replicas.
Database Instance Types: Flexible options for CPU, memory, storage, and networking based on requirements.
Flexibility: Full control over setup, configuration, and management of database engines.
Scalability: Easily scale up or down based on demand.
Customization: Ideal for database engines or versions not supported by RDS.
Cost Management: Potentially more cost-effective for certain configurations.
Feature | Amazon RDS | Amazon EC2 |
Management | Managed by AWS, reducing administrative overhead | Self-managed, full control |
Automation | High (automated backups, patching, and scaling) | Requires manual setup and management |
Flexibility | Limited to supported database engines and configurations | Highly flexible, any database engine/version |
Cost | Potentially higher due to managed services | Potentially lower, especially for large deployments |
Performance | Optimized with built-in high availability and replicas | Depends on user setup and configuration |
Security | Automated security patches and maintenance | User responsibility to manage security |
Management Overhead: RDS reduces management tasks, ideal for teams looking to offload database administration.
Flexibility Needs: EC2 offers more flexibility for custom database setups and unsupported engines.
Automation: RDS supports automation for deployments and backups, enhancing operational efficiency.
Cost Constraints: EC2 may be preferable for budget-sensitive projects requiring specific configurations.
Performance and Scaling: Both options can scale, but RDS offers simplified scaling with read replicas and built-in high availability.
PostgreSQL is a powerful, open-source RDBMS supported natively by both Amazon RDS and EC2. When deciding where to host PostgreSQL, you need to consider the tradeoffs.
Amazon Relational Database Service (RDS) for PostgreSQL provides a fully managed database solution in the cloud, automating many of the time-consuming administrative tasks associated with database management. This service supports the PostgreSQL database engine and handles backups, patches, scaling, and high availability.
Amazon Elastic Compute Cloud (EC2) allows you to run PostgreSQL on customizable virtual machines, giving you complete control over the database environment. With EC2, you can install and configure any version of PostgreSQL, providing a flexible and customizable solution for your database needs.
Feature | PostgreSQL on Amazon RDS | PostgreSQL on Amazon EC2 |
Management | Fully managed, including backups, patching, and upgrades | User-managed, requiring manual configuration and maintenance |
Performance Tuning | Limited access to underlying OS for fine-tuning | Full access to OS and database configuration |
Flexibility | Limited to RDS-supported PostgreSQL versions | Any version or custom builds can be installed |
Backups & Recovery | Automatic backups and point-in-time recovery | Customizable, but requires manual setup for snapshots or backup tools |
Scaling | Supports read replicas for scalability | Manual setup needed for replication and scaling |
Monitoring & Security | Integrated with AWS CloudWatch and automated security | Custom monitoring and security setup required |
Cost | Slightly higher due to managed service overhead | Potentially lower cost, but requires more hands-on management |
Maintenance Overhead | Low - AWS handles routine tasks | High - requires dedicated resources to manage updates, patching, etc. |
When your team prefers a hands-off approach for database management.
When you want built-in scaling with read replicas.
When automated backups and routine patching are critical.
When you need full control over the database environment.
When you require custom PostgreSQL versions or specific OS-level configurations.
When cost savings on large-scale deployments is important, and you have in-house expertise to manage the infrastructure.