AWS Certified Cloud Practitioner / Amazon S3

S3 Replication Overview

Amazon S3 replication allows you to automatically copy objects from one bucket to another.

There are two types:

  • 🌍 CRR – Cross-Region Replication

  • 🏠 SRR – Same-Region Replication


1️⃣ How Replication Works

  • Source bucket β†’ the original bucket

  • Destination bucket β†’ the target bucket

  • Both buckets must have versioning enabled πŸ”„

  • Replication is asynchronous ⏳ – happens in the background

  • IAM permissions must allow S3 to read from source and write to destination πŸ›‘οΈ

For CRR, buckets are in different regions 🌍

For SRR, buckets are in the same region 🏠


2️⃣ Replication Across Accounts

  • Buckets can belong to different AWS accounts πŸ‘₯

  • S3 handles replication automatically once permissions are set


3️⃣ Use Cases

Cross-Region Replication (CRR) 🌐

  • Compliance & regulatory requirements βœ…

  • Lower latency access in another region ⚑

  • Replicate data across accounts πŸ”

Same-Region Replication (SRR) 🏘️

  • Aggregate logs from multiple buckets πŸ“Š

  • Live replication for production β†’ test environments βš™οΈ


4️⃣ Key Points

  • Versioning is required on both source and destination πŸ”„

  • Replication is asynchronous, not instant ⏳

  • IAM permissions are critical for S3 to read/write πŸ”‘


Replication ensures data redundancy, compliance, and operational efficiency across regions and accounts.