Here are a few things to keep in mind as you start to think about how to make use of Cross-Region Replication in your own operating environment.
Versioning – As I mentioned earlier, you must first enable S3 versioning for the source and destination buckets.
Lifecycle Rules – You can choose to use Lifecyle Rules on the destination bucket to manage older versions by deleting them or migrating them to Amazon Glacier.
Determining Replication Status – You (or your code) can use the HEAD operation on a source object to determine its replication status. You can also (as you saw above) view this status in the Console.
Region-to-Region – Replication always takes place between a pair of AWS regions. You cannot use this feature to replicate content to two buckets that are in the same region.
New Objects – Because this feature watches the source bucket for changes, it replicates new objects and changes to existing objects. If you need to replicate existing objects, a solution built around the S3 COPY operation can be used to bring the destination bucket up to date.
how to make use of Cross-Region Replication.
