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Scaling Reads with RDS Read Replicas
Amazon RDS (Relational Database Service) provides many features to enhance performance, availability, and disaster recovery for cloud-based databases. Among the most valuable features is RDS Read Replicas, a solution designed to offload read operations from your primary database and enhance read scalability.
In this article, we’ll explore how RDS Read Replicas work, their architecture, and the use cases that benefit from this feature.
What Are RDS Read Replicas?
Read replicas in RDS allow you to create up to 15 read-only copies of your database. These replicas can be located:
- Within the same Availability Zone (AZ) for local traffic optimization
- Across different Availability Zones to improve fault tolerance
- Across different Regions for global traffic optimization and disaster recovery
The replication process between the primary database and its replicas is asynchronous, meaning that data changes made to the primary database are propagated to the read replicas after a slight delay. As a result, read replicas provide eventually consistent reads, meaning there might be a short lag before the replica reflects the latest changes.
