Disaster recovery approach share in AWS

AWS offers several disaster recovery (DR) strategies for multi-region implementations to ensure business continuity and minimize data loss. These strategies include:

1. Backup and Restore: This basic approach involves replicating data to another region and redeploying infrastructure when needed. You back up your data and applications into the recovery region, and when a disaster occurs, you deploy the infrastructure, code, and restore the backed-up data.

2. Pilot Light: In this approach, a minimal version of your environment is always running in the cloud. You maintain a copy of your core workload infrastructure in the recovery region with data replication and backups. This allows for quick activation during a disaster, minimizing the ongoing cost while simplifying recovery since core infrastructure is already in place.

3. Warm Standby: A scaled-down but fully functional copy of your production environment is maintained in another region. This approach keeps a fully functional version of the workload running in the recovery region with data replication and live data, enabling faster recovery and easier testing.

4. Multi-site Active/Active (Multi-Region Active-Active): Your workloads run simultaneously in multiple regions, serving traffic from all regions. This provides near-zero recovery times for most disasters but requires your application to be designed to handle multi-region deployment.

To implement these strategies effectively, AWS provides several services:

• AWS Elastic Disaster Recovery (DRS): Continuously replicates applications and databases from various sources to AWS using block-level replication, allowing for quick failover with minimal data loss.
• Amazon Route 53 and AWS Global Accelerator: For traffic routing and deployment across multiple regions.
• Amazon S3 Cross-Region Replication: Ensures data is available in multiple regions.
• Infrastructure as Code (IaC): Enables quick and error-free recovery by automating deployments across multiple accounts and regions.

For workloads with regulatory data residency requirements in localities with only one AWS Region, multi-region strategies may not be suitable. In such cases, multi-AZ strategies within a single region can provide good protection against most disasters.

Regular testing of DR plans is crucial for ensuring their effectiveness. AWS DRS allows for non-disruptive failback drills without impacting production systems.
Sources
DR and Fault Tolerance | AWS re:Post
Disaster recovery options in the cloud - Disaster Recovery of Workloads on AWS: Recovery in the Cloud
REL13-BP02 Use defined recovery strategies to meet the recovery objectives - AWS Well-Architected Framework
REL13-BP02 Use defined recovery strategies to meet the recovery objectives - AWS Well-Architected Framework