AWS S3 buckets are highly reliable but it is worthwhile to be aware that the contents of a bucket are stored in a single region. Because of this there is always a risk that a regional outage might result in bucket contents not being available to other regions.

A way to resolve this is to use the AWS S3 Cross Region Replication support in S3. This will cause any object stored in a bucket that has been so configured to be replicated to a bucket in a different region.

An example of doing that using CloudFormation to create the 2 different buckets can be found at

An example of where this might be helpful is in disaster recovery plans where it is necessary to ensure that bucket data is always available even in a regional outage situation.