Database Sharding vs. Read Replicas: High-Throughput Scaling Bottlenecks

Identifying write amplification, connection pool exhaustion, and replication lag before they compromise mission-critical SLAs.

MA
• 6 min read • 1,280 words

Horizontal database scaling is rarely as simple as spinning up additional read replicas. Replication lag introduces subtle consistency anomalies that break financial transactions. We evaluate hash-based sharding versus virtual vnode distribution.

MA

Staff Security Researcher and Cryptography Lead at Sentinel Security. Author of multiple zero-trust workload identity RFCs and Kubernetes security audits.

Contributing Author affiliated with Sentinel Security Systems