Amazon DocumentDB
Developer Guide

Cluster Snapshot Considerations

Amazon DocumentDB creates daily automatic snapshots of your cluster during your cluster's backup window. Amazon DocumentDB saves the automatic snapshots of your cluster according to the backup retention period that you specify. If necessary, you can recover your cluster to any point in time during the backup retention period.

Automatic snapshots follow these rules:

  • Your cluster must be in the available state for an automatic snapshot to be taken.

  • Automatic snapshots don't occur while a copy operation is executing in the same Region for the same cluster.

In addition to automatic cluster snapshots, you can also manually create a cluster snapshot. For more information about manually creating a cluster snapshot, see Creating a Manual Cluster Snapshot.

You can perform the following operations with your snapshots:

Snapshot Storage

Your Amazon DocumentDB snapshot storage for each AWS Region is composed of the automated cluster snapshots and manual cluster snapshots for that Region. Your snapshot storage is equivalent to the sum of the database storage for all instances in that Region.

When you delete a cluster, all of its automatic snapshots are deleted and cannot be recovered. However, if you choose to have Amazon DocumentDB create a final snapshot before your cluster is deleted, you can use the final snapshot to recover your cluster.

Manual snapshots are not deleted when you delete a cluster.

For more information on snapshots and storage, see Understanding Backup Storage Usage.

Backup Window

Automatic snapshots occur daily during the preferred backup window. If the snapshot requires more time than allotted to the backup window, the backup process continues until it finishes, even though the backup window has ended. The backup window can't overlap with the weekly maintenance window for the cluster.

If you don't specify a preferred backup window when you create the cluster, Amazon DocumentDB assigns a default 30-minute backup window. This window is chosen at random from an 8-hour block of time associated with your cluster's Region. The following table lists the time blocks for each Region from which the default backups windows are assigned.

Region UTC Time Block
US East (N. Virginia) 03:00-11:00
US East (Ohio) 03:00-11:00
US West (Oregon) 06:00-14:00
EU (Ireland) 22:00-06:00
Asia Pacific (Tokyo) 13:00-21:00

You can change your preferred backup window by modifying the cluster. Use the AWS Management Console or AWS CLI to change the backup window. For more information, see Modifying an Amazon DocumentDB Cluster.

Backup Retention Period

The backup retention period is the number of days an automatic backup is retained before being automatically deleted. Amazon DocumentDB supports a backup retention period of 1–35 days.

You can set the backup retention period when you create a cluster. If you don't explicitly set the backup retention period, the default backup retention period of 1 day is assigned to your cluster. After you create a cluster, you can modify the backup retention period by modifying the cluster using either the console or the AWS CLI. For more information, see Modifying an Amazon DocumentDB Cluster.