S3 Replication

Links: 101 AWS SAA Index

  • There are two kinds of replication CRR (Cross Region Replication) and SRR (Same Region Replication).
    • Same-Region Replication (SRR) and Cross-Region Replication (CRR) can be configured at the S3 bucket level, a shared prefix level, or an object level using S3 object tags.
  • For replication both the buckets must have versioning enabled.
  • Buckets can be in different account.
  • S3 lifecycle actions are NOT replicated with S3 replication
  • Copying is asynchronous

  • Use cases:

    • CRR: compliance, lower latency access, replication across accounts
    • SRR: log aggregation, live replication between production and test accounts

  • After activation only new objects are replicated.

    • We can replicate existing objects using S3 Batch Replication.
If you want to copy the data from one bucket to another then you should probably use aws s3 sync command. Why?

As the data already exists in the source bucket, so you cannot use cross-Region replication because, by default, replication only supports copying new Amazon S3 objects after it is enabled. Replication enables automatic, asynchronous copying of objects across Amazon S3 buckets.

  • For DELETE operations:

    • Can replicate delete markers from source to target (optional setting)
    • Deletions with a version ID are not replicated (to avoid malicious deletes)

  • There is no chaining of replication

    • If bucket 1 has replication into bucket 2, which has replication into bucket 3 then objects created in bucket are not replicated to bucket 3.

  • The version ID of the replicated object will be same.

Go for replication incase the question asks for HA or Disaster Recovery.

Last updated: 2023-02-11