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Cloud Backups

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Note
Feature Unavailable in Free-Tier Clusters

This feature is not available for M0 free clusters. To learn more about which features are unavailable, see Atlas M0 (Free Cluster), M2, and M5 Limitations.

Atlas Cloud Backups provide localized backup storage using the native snapshot functionality of the cluster's cloud service provider.

Note

You must have the Project Owner role for an Atlas project to manage backup for the clusters in that project.

Atlas supports cloud backup for clusters served on:

You can enable cloud backup during the cluster creation or during the modification of an existing cluster. From the cluster configuration modal, toggle Turn on Cloud Backup to Yes.

If you need to retain any legacy backup snapshots for archival purposes, download them before you switch to Cloud Backup from legacy backups. To learn how to download a snapshot, see Restore a Cluster from a Legacy Backup Snapshot.

Important
Limitations of Cloud Backup

Cloud Backups:

  • Can support sharded clusters running MongoDB version 3.6 or later.
  • Cannot restore an existing snapshot to a cluster after you add or remove a shard from it. You may restore an existing snapshot to another cluster with a matching topology.
Note
Sharded Cluster Balancer, FCV 4.0 databases and Cloud Backup

With databases running FCV 4.0 or earlier, Cloud Backup automatically disables the balancer for snapshots if it's running. This ensures an inactive balancer during the backup operation. When the snapshot completes, Cloud Backup returns the balancer to its previous state.

Atlas encrypts the storage engine of all snapshot volumes, ensuring the security of cluster data at rest. For projects and clusters using Encryption at Rest using Customer Key Management, Atlas applies an additional layer of encryption to your snapshot storage volumes using the Key Management Service (KMS) provider configured for the cluster.

To view the key used to encrypt a snapshot:

  1. Click Databases in the top-left corner of Atlas.
  2. From the Database Deployments view of the Atlas UI, click on the cluster name.
  3. Click the Backup tab, then click Snapshots.
  4. Note the Encryption Key ID for each snapshot in the cluster. Atlas lists the Key Identifier used to encrypt the snapshot. Unencrypted snapshots display Not enabled.
Important

Atlas requires access to the encryption key associated to the snapshot's Encryption Key ID to successfully restore that snapshot.

Before deleting an Encryption Key ID used with Atlas Encryption at Rest using your Key Management, check every backup-enabled cluster in the project for any snapshots still using that Encryption Key ID. Once you delete an encryption key, all snapshots encrypted with that key become inaccessible and unrecoverable.

Atlas automatically deletes backups in accordance to the Snapshot Scheduling and Retention Policy. Once Atlas deletes all snapshots depending on a given Encryption Key ID, you can delete the key safely.

If disabling a Encryption Key ID, you must re-enable the key before restoring a snapshot encrypted with that key.

For complete documentation on configuring Encryption at Rest using your Key Management for an Atlas project, see Encryption at Rest using Customer Key Management. You can then either deploy a new cluster or enable an existing cluster with Encryption at Rest using your Key Management.

With single-region cluster backups, Atlas:

  • Determines the order of nodes to try to snapshot using the following algorithm:

    1. Snapshots on a secondary. 1 Then,
    2. Snapshots the node with the lowest priority if possible. 2 Then,
    3. Snapshots incrementally from one snapshot to the next if possible. 3 Then,
    4. Snapshots node lexically first by hostname.

    1 If there is a tie, Atlas skips to the next step to determine the node to snapshot.

    2 If there is a tie, Atlas then favors the node that can be snapshotted incrementally from the previous snapshot (i.e., node using the same disk).

    3 If there is a tie, Atlas then favors the node with the lexicographically smallest hostname.

  • Once the node order is determined, tries to snapshot a node. If a selected node is unhealthy, Atlas tries to snapshot the next node that it favors.
  • Stores the snapshots in the same cloud region as the cluster.
  • Retains snapshots based on your retention policy.

Atlas automatically creates a new snapshot storage volume if the existing snapshot storage volume becomes invalid. Atlas creates the new volume in the same region as the cluster's current primary. Atlas then takes a full-copy snapshot to maintain backup availability and continues using that member and its corresponding region for further incremental snapshots.

Events that can cause an election to select a new node for the snapshot storage volume include:

  • Changing the Atlas cluster tier,
  • Modifying the Atlas cluster's storage volume or speed,
  • Changing the Atlas cluster's region, and
  • Maintenance performed by Atlas or the cluster's cloud provider.
Tip
See also:

To learn more about snapshot retention, see Snapshot Scheduling and Retention Policy.

With multi-region cluster backups, Atlas:

  • Determines the order of nodes to snapshot using the following algorithm:

    1. Snapshots in the highest priority region if possible. 1 Then,
    2. Snapshots on a secondary. 2 Then,
    3. Snapshots the node with the lowest priority if possible. 3 Then,
    4. Snapshots incrementally from one snapshot to the next if possible. 4 Then,
    5. Snapshots node lexically first by hostname.

    1 If there is a tie, Atlas then compares based on the descending order of priority.

    2 If there is a tie, Atlas skips to the next step to determine the node to snapshot.

    3 If there is a tie, Atlas then favors the node that can be snapshotted incrementally from the previous snapshot (i.e., node using the same disk).

    4 If there is a tie, Atlas then favors the node with the lexicographically smallest hostname.

  • Tries to snapshot a node once the node order is determined. If a selected node is unhealthy, Atlas tries to snapshot the next node that it favors.
  • Retains snapshots based on your retention policy.

Atlas automatically creates a new snapshot storage volume if the existing snapshot storage volume becomes invalid. Atlas creates the new volume in the same region as the cluster's current primary. Atlas then takes a full-copy snapshot to maintain backup availability and continues using that member and its corresponding region for further incremental snapshots.

Events that can cause an election to select a new node for the snapshot storage volume include:

  • Changing the Atlas cluster tier,
  • Modifying the Atlas cluster's storage volume or speed,
  • Changing the Atlas cluster's highest priority region, and
  • Maintenance performed by Atlas or the cluster's cloud provider.
Tip
See also:

To learn more about snapshot retention, see Snapshot Scheduling and Retention Policy.

Atlas can back up Global Clusters using Cloud Backups as their backup method. Atlas restores the shards in the source cluster to the corresponding shards in the target cluster using the same order as specified in the cluster configuration.

Example

shard0 in the source cluster is restored to shard0 in the target cluster.

Note

If you used the API to create your Global Cluster, the zones are defined in the replicationSpecs parameter in the Create a Cluster and Modify a Cluster API endpoints.

If the cluster configurations of the source and target clusters do not match, shard data may migrate to a different cloud provider zone than where it resided in the source cluster. After Atlas completes the restore operation, the MongoDB balancer for the target cluster migrates the data back to the zone where it resided in the source cluster if your clusters meet the following requirements:

  • Both clusters have enabled a Global Cluster on the same collection
  • Both clusters use the same shard key for the Global Writes-enabled collection
Note

If the Global Writes-enabled collection on the target cluster does not contain any data, the MongoDB balancer for the cluster automatically distributes any data that you later add to the collection among the target cluster's shards.

To enable global writes on the target cluster:

  1. Click Databases in the top-left corner of Atlas.
  2. Click Browse Collections beneath the target cluster on the Database Deployments page.
  3. Click Enable Global Writes.

Continuous Cloud Backups replay the oplog to restore a cluster from a particular point in time within a window specified in the Backup Policy.

You may opt to enable Continuous Cloud Backup restores. Configure your continuous cloud backup window with the Backup Policy Editor.

Note

Enabling continuous cloud backups increases the monthly cost of your cluster.

To learn more about the cost implications, see billing.

Your cluster's snapshots stay within the cloud provider's storage service under the cluster or shard's highest priority region. Oplog backups on AWS clusters use standard AWS S3 encryption.

Note

All clusters with continuous cloud backups enabled store oplog data on AWS S3, including clusters backed by Azure and Google Cloud.

The following actions cause all existing oplog backups to be deleted. All existing snapshots remain intact, but Atlas removes previously preserved oplog data when:

  • You disable continuous cloud backups for your cluster.
  • The cluster receives an excessive number of writes. The cluster processes a large number of writes that causes the oplog to roll over before backup collects it.

    Example
    1. You sized your oplog for one hour of its usual write traffic, say 1,000 operations.
    2. Database activity results in a large number of writes to the oplog, say 2,000 operations.
    3. The number of writes result in the oplog dropping older records. This example would lose 1,000 operations.
    4. Backup should collect operation #1, but it collects #1,001 instead.
  • Perform a restore into the cluster.

If you change your cluster's highest priority region or if MongoDB migrates oplog data to a different region:

  • Atlas retains data in both the old and new regions until your continuous cloud backup window is represented in the new region. Once the continuous cloud backup window is represented in the new region, Atlas deletes the data in the old region.
  • You will be billed for storage in both the old and new regions for the days following the region change. You must disable continuous cloud backup and reenable it to prevent billing in both regions.

    Note

    If you disable continuous cloud backup, Atlas will delete the continuous cloud backup history.

Use the Backup Policy Editor to configure a backup policy for Cloud Backups.

  1. Click Databases in the top-left corner of Atlas.
  2. From the Database Deployments view, click the cluster name.
  3. Click the Backup tab.
  4. Click Backup Policy.

A backup policy has the following sections:

  • A time of day, in UTC, at which to create snapshots.
  • A frequency interval and duration of retention.
  • If PIT Restores are enabled, a PIT window that allows you to restore to any point in time in the last X days where X is the window.
Example

The default backup policy specifies a snapshot time of 18:00 UTC and the following four policy items:

Policy Type
Tier
Continuous Cloud Backup
Snapshot Taken
Snapshot Retained
Hourly

NVMe

Enabled
Every 12 hours
2 days
Hourly
non-NVMe
Enabled
Every 6 hours
2 days
Daily
All
Either
Every day
7 days
Weekly
All
Either
Every Saturday
4 weeks
Monthly
All
Either
Last day of the month
12 months

To learn more about Cloud Backup billing, see Cloud Backups.

To modify the backup policy time:

  1. In the Backup Policy Editor, select the hour at which Atlas takes a snapshot each day from hr beneath Snapshot Time (UTC).
  2. Select the number of minutes after hr at which Atlas takes a snapshot from min beneath Snapshot Time (UTC).
  3. Click Save Changes.

Each row in the Backup Policy Frequency and Retention table represents a backup policy item. Configure the policy items and, optionally, add new policy items to configure a new backup policy.

Tip

Atlas displays the estimated number of snapshots associated with your changes below the Backup Policy Frequency and Retention table.

To specify a backup policy item:

  1. Select the frequency unit from Frequency Unit for a policy item.

    Alternatively, click Add Frequency Unit to add a new policy item to the backup policy.

    Note

    You cannot specify multiple Hourly and Daily backup policy items.

  2. Select the frequency for the frequency unit from Every.

    Note

    If you delete an existing backup frequency unit, the snapshots for which the frequency was specified remain intact until they expire or you delete them.

  3. Specify the retention time for the policy item in Retention Time and the units for the retention time from the list to the right.

    Note

    Atlas requires that the value specified for Retention Time for items that are less frequent is equal to or larger than the value specified for items that are more frequent. For example, if the hourly policy item specifies a retention of two days or greater, the retention for the weekly snapshot must be two weeks or greater.

    You can't configure a restore window that is longer than the Hourly Snapshot Retention Time.

  4. (Optional) To apply the retention changes in the updated backup policy to snapshots that Atlas took previously, check Apply policy retention changes to existing snapshots.

    Note

    This option affects only snapshots created by the updated policy items and whose retention has not been updated individually with the Modify Cloud Backup Backup Policy API.

  5. Click Save Changes.
Note

To take a snapshot sooner than the next scheduled snapshot, use the Take One On-Demand Snapshot API.

Note

If overlapping policy items generate the same snapshot, Atlas associates the snapshot with the policy item with the longest retention time.

Example

If the policy specifies a daily snapshot with a retention of two days and a weekly snapshot every Saturday with a retention of three weeks, Atlas must choose which frequency unit to associate with the snapshot taken on Saturday, hourly or weekly.

Since the retention time for the weekly policy item is longer than that specified for the hourly policy item, Atlas displays a frequency of Weekly in the Frequency column on the Snapshots page for the snapshot taken on Saturday.

Important

If you disable Cloud Backups for a cluster or terminate a cluster that had snapshots enabled, Atlas immediately deletes the backup snapshots for that cluster. For clusters not using Encryption at Rest using Customer Key Management you can download the latest snapshot to preserve any data stored in the cluster.

You can replay the oplog to restore a cluster from any point in time within a specified restore window.

To specify the restore window duration, select how long you want Atlas to retain the oplog for point-in-time restores from the Restore Window list.

Note

You can't configure a restore window that is longer than the Hourly Snapshot Retention Time.

Atlas displays existing snapshots on the Snapshots page. To view snapshots that Atlas has already taken:

  1. Click Databases in the top-left corner of Atlas.
  2. From the Database Deployments view, click the cluster name.
  3. Click the Backup tab.
  4. Click Snapshots.

By default, Atlas displays both on-demand and policy-based snapshots. To view only policy-based snapshots:

  1. Click Policy under View Snapshots by.

    Alternatively, click On-demand to display only snapshots taken by clicking Take Snapshot Now.

Snapshots taken according to the backup policy display the frequency of the policy item that generated the snapshot in the Frequency column: Monthly, Weekly, Daily, or Hourly.

Note

If overlapping policy items generate the same snapshot, Atlas associates the snapshot with the policy item with the longest retention time.

Example

If the policy specifies a daily snapshot with a retention of two days and a weekly snapshot every Saturday with a retention of three weeks, Atlas must choose which frequency unit to associate with the snapshot taken on Saturday, hourly or weekly.

Since the retention time for the weekly policy item is longer than that specified for the hourly policy item, Atlas displays a frequency of Weekly in the Frequency column on the Snapshots page for the snapshot taken on Saturday.

Atlas takes on-demand snapshots immediately, unlike scheduled snapshots which occur at regular intervals. If there is already an on-demand snapshot with a status of queued or inProgress, you must wait until Atlas has completed the on-demand snapshot before taking another. If there is already a scheduled snapshot with a status of queued or inProgress, you may queue an on-demand snapshot. You must have the Organization Owner or Project Owner role to successfully call this endpoint.

To take an on-demand snapshot:

  1. Click Databases in the top-left corner of Atlas.
  2. From the Database Deployments view, click the button below the cluster name then click Take Snapshot Now.
  3. In the On-Demand Snapshot modal, enter the following:

    1. In the Retention box, enter the number of days that you want Atlas to retain the snapshot.
    2. In the Description box, enter a descriptive name for the snapshot.
  4. Click Take Snapshot.

Click the Backup tab, then click Snapshots for the cluster to view the on-demand snapshot.

Note

The Take Snapshot Now button also appears on the Snapshots page for the cluster.

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