Why is it taking a long time to replicate Amazon S3 objects when I use Cross-Region Replication between my buckets?

Short description

CRR is an asynchronous process that eventually replicates the objects. Most object replication is within 15 minutes, but sometimes replication can take up to 48 hours. Several factors affect replication time, including:

• The Region of the source and destination.
• The size of the objects to replicate. For large objects, replication can take up to several hours.
• The number of objects to replicate.
• If the object has AWS Key Management Service (AWS KMS) encryption turned on, then AWS KMS throttles transactions.

Resolution

Check the replication status on your source object. The replication status can help you determine the current state of an object. If the object replication status is PENDING, then Amazon S3 hasn't completed the replication.

Use S3 Replication metrics to get detailed metrics for your replication rules. With replication metrics, you can monitor minute-by-minute progress for bytes pending, operations pending, operations that failed replication, and replication latency.

Note: S3 Replication metrics are billed at the same rate as Amazon CloudWatch custom metrics. For more information, see Amazon CloudWatch pricing.

You can get visibility into replication with S3 Replication Time Control (S3 RTC), and monitor progress with replication status information and replication metrics. You can turn on S3 Replication metrics when you create or edit a rule, or use S3 RTC. S3 RTC replicates most objects that you upload to Amazon S3 in seconds, and 99.9% of those objects within 15 minutes. S3 RTC automatically turns on S3 Replication metrics.

Note: CloudWatch begins to report replication metrics 15 minutes after you turn on S3 RTC on a replication rule.