Requirements and considerations for replication - Amazon Simple Storage Service
Considerations for replication

Requirements and considerations for replication

Amazon S3 replication requires the following:

  • The source bucket owner must have the source and destination AWS Regions enabled for their account. The destination bucket owner must have the destination Region enabled for their account.

    For more information about enabling or disabling an AWS Region, see Managing AWS Regions in the AWS General Reference.

  • Both source and destination buckets must have versioning enabled. For more information about versioning, see Using versioning in S3 buckets.

  • Amazon S3 must have permissions to replicate objects from the source bucket to the destination bucket or buckets on your behalf. For more information about these permissions, see Setting up permissions for live replication.

  • 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 access control list (ACL). For more information, see Access control list (ACL) overview.

  • If the source bucket has S3 Object Lock enabled, the destination buckets must also have S3 Object Lock enabled.

    To enable replication on a bucket that has Object Lock enabled, you must use the AWS Command Line Interface, REST API, or AWS SDKs. For more general information, see Using S3 Object Lock.

    Note

    You must grant two new permissions on the source S3 bucket in the AWS Identity and Access Management (IAM) role that you use to set up replication. The two new permissions are s3:GetObjectRetention and s3:GetObjectLegalHold. If the role has an s3:Get* permission, it satisfies the requirement. For more information, see Setting up permissions for live replication.

For more information, see Setting up live replication.

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

Considerations for replication

Before you create a replication configuration, be aware of the following considerations.

Lifecycle configuration and object replicas

The time it takes for Amazon S3 to replicate an object depends on the size of the object. For large objects, it can take several hours. Although it might take a while before a replica is available in the destination, it takes the same amount of time to create the replica as it took to create the corresponding object in the source bucket. If a lifecycle configuration is enabled on a destination bucket, the lifecycle rules honor the original creation time of the object, not when the replica became available in the destination bucket.

Replication configuration requires the bucket to be versioning-enabled. When you enable versioning on a bucket, keep the following in mind:

  • If you have an object Expiration lifecycle configuration, after you enable versioning, add a NonCurrentVersionExpiration policy to maintain the same permanent delete behavior as before you enabled versioning.

  • If you have a Transition lifecycle configuration, after you enable versioning, consider adding a NonCurrentVersionTransition policy.

Versioning configuration and replication configuration

Both the source and destination buckets must be versioning-enabled when you configure replication on a bucket. After you enable versioning on both the source and destination buckets and configure replication on the source bucket, you will encounter the following issues:

  • If you attempt to disable versioning on the source bucket, Amazon S3 returns an error. You must remove the replication configuration before you can disable versioning on the source bucket.

  • If you disable versioning on the destination bucket, replication fails. The source object has the replication status FAILED.

Using S3 Replication with S3 Intelligent-Tiering

S3 Intelligent-Tiering is a storage class that is designed to optimize storage costs by automatically moving data to the most cost-effective access tier. For a small monthly object monitoring and automation charge, S3 Intelligent-Tiering monitors access patterns and automatically moves objects that have not been accessed to lower-cost access tiers.

Replicating objects stored in S3 Intelligent-Tiering with S3 Batch Replication or invoking CopyObject or UploadPartCopy constitutes access. In these cases, the source objects of the copy or replication operations are tiered up.

For more information about S3 Intelligent-Tiering see, Amazon S3 Intelligent-Tiering.

Logging configuration and replication configuration

If Amazon S3 delivers logs to a bucket that has replication enabled, it replicates the log objects.

If server access logs (Logging requests with server access logging) or AWS CloudTrail logs (Logging Amazon S3 API calls using AWS CloudTrail) are enabled on your source or destination bucket, Amazon S3 includes replication-related requests in the logs. For example, Amazon S3 logs each object that it replicates.

CRR and the destination Region

Amazon S3 Cross-Region Replication (CRR) is used to copy objects across S3 buckets in different AWS Regions. You might choose the Region for your destination bucket based on either your business needs or cost considerations. For example, inter-Region data transfer charges vary depending on the Regions that you choose.

Suppose that you chose US East (N. Virginia) (us-east-1) as the Region for your source bucket. If you choose US West (Oregon) (us-west-2) as the Region for your destination buckets, you pay more than if you choose the US East (Ohio) (us-east-2) Region. For pricing information, see "Data Transfer Pricing" in Amazon S3 pricing.

There are no data transfer charges associated with Same-Region Replication (SRR).

S3 Batch Replication

For information about considerations for Batch Replication, see S3 Batch Replication considerations.

S3 Replication Time Control

For information about best practices and considerations for S3 Replication Time Control (S3 RTC), see Best practices and guidelines for S3 RTC.