Read Replicas
Read replicas are a database scaling technique that involves creating one or more copies (replicas) of a primary database to handle read-only queries, offloading read traffic from the primary instance. This improves performance and availability by distributing read workloads, while the primary database remains responsible for write operations and data consistency. It is commonly used in relational databases like MySQL, PostgreSQL, and cloud database services to enhance scalability and fault tolerance.
Developers should use read replicas when their applications experience high read traffic that could overwhelm a single database instance, such as in e-commerce sites, content management systems, or analytics platforms. This approach reduces latency for read queries, increases throughput, and provides redundancy for disaster recovery, allowing the primary database to focus on critical write operations without performance degradation.