Zero Data Loss Migration: Moving Billions of Rows from SQL Server to Aurora RDS — Architecture, Predictive CDC Monitoring & Lessons from Production

Migrating billions of rows from SQL Server to Aurora RDS used parallel AWS DMS instances for resource isolation and DMS-PredictLagNet with Holt-Winters forecasting to predict CDC lag. Network architecture employed dual VPNs to Transit Gateway, with critical lessons on post-NAT address configuration and mandatory Reachability Analyzer checks. Schema conversion via AWS SCT on EC2 with Secrets Manager ensured SOC 2 and PCI DSS compliance before data load.

Implement parallel DMS instances and predictive CDC lag monitoring to achieve zero-data-loss migrations in resource-constrained, high-volume environments.