Amazon Simple Storage Service
Developer Guide (API Version 2006-03-01)

Cross-Region Replication

Cross-region replication (CRR) enables automatic, asynchronous copying of objects across buckets in different AWS Regions. Buckets configured for cross-region replication can be owned by the same AWS account or by different accounts.

Cross-region replication is enabled with a bucket-level configuration. You add the replication configuration to your source bucket. In the minimum configuration, you provide the following:

  • The destination bucket, where you want Amazon S3 to replicate objects

  • An AWS IAM role that Amazon S3 can assume to replicate objects on your behalf

Additional configuration options are available.

When to Use CRR

Cross-region replication can help you do the following:

  • Comply with compliance requirements—Although Amazon S3 stores your data across multiple geographically distant Availability Zones by default, compliance requirements might dictate that you store data at even greater distances. Cross-region replication allows you to replicate data between distant AWS Regions to satisfy these requirements.

     

  • Minimize latency—If your customers are in two geographic locations, you can minimize latency in accessing objects by maintaining object copies in AWS Regions that are geographically closer to your users.

     

  • Increase operational efficiency—If you have compute clusters in two different AWS Regions that analyze the same set of objects, you might choose to maintain object copies in those Regions.

     

  • Maintain object copies under different ownership—Regardless of who owns the source object you can tell Amazon S3 to change replica ownership to the AWS account that owns the destination bucket. This is referred to as the owner override option. You might use this option restrict access to object replicas.

Requirements for CRR

Cross-region replication requires the following:

  • Both source and destination buckets must have versioning enabled.

  • The source and destination buckets must be in different AWS Regions.

  • Amazon S3 must have permissions to replicate objects from the source bucket to the destination bucket on your behalf.

  • If the owner of the source bucket doesn't own the object in the bucket, the object owner must grant the bucket owner READ and READ_ACP permissions with the object ACL. For more information, see Managing Access with ACLs.

For more information, see Overview of Setting Up CRR .

If you are setting the replication configuration in a cross-account scenario, where source and destination buckets are owned by different AWS accounts, the following additional requirements apply: