How to sync from 2 databases in AWS

Question

I have 2 mysql databases with different VPC in RDS.

let say database A from application A and database B from application B.

Currently I have plan to moving from application A to application B without downtime.

And for backup plan also I want both applications are still running simultaneously.

Any idea how to create a sync process if data coming from application A and application B also got reflected without directly insert to database B and vice versa ?

adding notes : both databases has different table format because both coming from different applications.

Thank you

Answer 1

• First - you need set up replication DB_A from VPC_A into VPC_B.
• Second - after replica synchronized (content full copy of DB_A) you can switch application A fro use DB_A_replication on VPC_B
• Third - you can stop replication between DB_A and DB_A_replication

So at end of migration you will have 2 separate databases on same host (VPC_B)