AWS Disaster Recovery (DR) refers to the strategies, tools, and services that help organizations recover their IT infrastructure and applications in the event of a disaster, such as an outage, system failure, or natural disaster. AWS provides a range of services and approaches that enable businesses to build a resilient disaster recovery solution to quickly recover critical workloads.
Key AWS Disaster Recovery Approaches:
AWS offers several approaches for implementing disaster recovery, depending on your RPO (Recovery Point Objective) and RTO (Recovery Time Objective) requirements. The primary approaches are:
- Backup and Restore:
- This is the most basic and cost-effective disaster recovery strategy.
- In this approach, data is backed up regularly (e.g., daily or weekly) and stored on AWS services such as Amazon S3, Amazon Glacier, or Amazon EBS Snapshots.
- If a disaster occurs, you restore the data from backups to a new EC2 instance or environment.
- This strategy is ideal for workloads with a low tolerance for downtime but does not require near-instantaneous recovery.
- Pilot Light:
- In this model, a minimal version of your environment is always running in AWS (e.g., a scaled-down version of your application, database, and necessary resources).
- The pilot light setup allows you to maintain essential services in the cloud, and in the event of a disaster, you can scale up and fully restore the environment quickly.
- For example, you might run critical database servers or a small portion of your application continuously on AWS while keeping the rest of your infrastructure on-premises. In a disaster, the full-scale environment is launched from AWS resources.
- RTO: Moderate to low; RPO: Moderate.
- Warm Standby:
- A warm standby solution involves running a scaled-down version of your production environment in AWS. This environment is always operational, but it is scaled down to a minimal level (e.g., fewer EC2 instances or a smaller database cluster).
- In the event of a disaster, you can quickly scale the infrastructure in AWS to match the capacity of your production environment, minimizing downtime and ensuring continuity of service.
- RTO: Low; RPO: Low.
- Multi-Site (Hot Standby):
- In a multi-site approach, your full-scale environment runs simultaneously in both on-premises and AWS locations, with real-time replication and synchronization between the two sites.
- If a disaster occurs at the primary site, the secondary AWS site immediately takes over, ensuring zero downtime and no data loss.
- This is the most resilient solution but also the most costly since it requires running full infrastructure in both environments.
- RTO: Near-zero; RPO: Near-zero.