Aurora Migration Toolkit

Migrating a single database to Aurora is a project. Migrating fifty — including multi-terabyte, tier-0 systems with 24/7 write traffic — is a platform. This is the toolkit and methodology that made it repeatable.

Challenge

Each team’s database had different constraints: replication lag budgets, change-freeze windows, version skew between on-premises MySQL and Aurora, and applications that had grown assumptions about their database over a decade. One-off migration plans did not scale to fifty of them.

Approach

• One pipeline, parameterized per database. A CDC-based replication path with a rehearsed cutover runbook, tuned per workload instead of rewritten per workload.
• Rehearsal as a gate. Every cutover was executed against a restored copy first, with the same scripts, same checks, same rollback points.
• Cutover under 3 minutes. The downtime budget was a design input, not an outcome: DNS weights, connection drains, and write-freeze verification were automated and timed.

Result

About 50 production databases migrated over two years. Most cutovers took under 3 minutes of downtime; the tier-0 systems nobody wanted to touch went first, because the process was most trustworthy there.