Resilience in Amazon DocumentDB

An Amazon DocumentDB cluster can only be created in an Amazon VPC that has at least two subnets in at least two Availability Zones. By distributing your cluster instances across at least two Availability Zones, Amazon DocumentDB helps ensure that there are instances available in your cluster in the unlikely event of an Availability Zone failure. The cluster volume for your Amazon DocumentDB cluster always spans three Availability Zones to provide durable storage with less possibility of data loss.

For more information about AWS Regions and Availability Zones, see AWS Global Infrastructure.

Fault-tolerant and self-healing storage

Each 10 GB portion of your storage volume is replicated six ways, across three Availability Zones. Amazon DocumentDB uses fault-tolerant storage that transparently handles the loss of up to two copies of data without affecting database write availability, and up to three copies without affecting read availability. Amazon DocumentDB storage is also self-healing; data blocks and disks are continuously scanned for errors and replaced automatically.

Amazon DocumentDB provides the capability to create full backups of your cluster for long-term retention and recovery. For more information, see .

Point-in-time recovery