For an updated ready-to-use CloudFormation template of this code, see newer
post: Complete code: cross-region RDS recovery
.
Amazon RDS is a great database-as-a-service, which takes care of almost all database-related maintenance tasks for you -
everything from automated backups and patching to replication and fail-overs into another availability zones.
Unfortunately all of this fails if the region where your RDS is hosted fails. Region-wide failures are very
rare, but they do happen! RDS does not support cross-region replication at the
moment, so you cannot simply create a replica of your database in another region (unless you host the database on an EC2
instance and set up the replication yourself). The second-best option, to make sure you can restore your service quickly
in another region, is to always have a copy of your latest database backup in that region. In case of RDS, that can mean
copying automated snapshots. There is no option for AWS to do it automatically, but it can be easily scripted with AWS
Lambda functions.