AWS Interview DropAdvanced TierScenario+50 XP on read1saved
How do you architect a highly available, zero-downtime database migration in AWS RDS?
Core Summary
Zero downtime means you never ask for a maintenance window. Bring the new database up next to the old one, keep it in sync while the old one carries all the traffic, check the data constantly, then switch connections over in a few seconds, with a way back you set up before you need it.
Hints
Hint 1: DMS with CDC keeps the target in sync while the source serves traffic
Hint 2: The cutover happens at the DNS or proxy layer, not in the database
Hint 3: Plan the rollback before the cutover, not after
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