Serverless instances are in preview and do not support this feature at this time. To learn more, see Serverless Instance Limitations.
Atlas supports changing a cluster's region and cloud provider:
- When you increase the cluster tier of an
- Anytime on an
Each node in the preferred and electable regions can:
- Participate in replica set elections
- Become the primary if the majority of replica set nodes are available.
Electable nodes in the cluster must total 3, 5, or 7.
Depending on the amount of data to migrate, migrations can take a significant amount of time. To maximize availability for a replica set, Atlas migrates one member at a time, starting with the secondary members first and then the primary.
Migration can affect performance if your primary is already reaching operational capacity: each newly migrated replica set member must perform an initial sync from the primary, adding to the operational load. Migrations can also affect performance if read preferences are set to read from secondaries: the replica set is down one secondary during the migration.
If you move a cluster out of a region that has a VPC (Virtual Private Cloud) peering connection, the moved cluster can no longer use that peering connection to communicate with servers in the VPC. Any other clusters with nodes remaining in the original region can continue to use the VPC peering connection.
You can create multiple VPC connections for each region, including a new VPC peering connection with the region that you moved a cluster to.
Cluster nodes removed from a region can't inherit access rules from an AWS security group or allowed VPC CIDR blocks configured for the VPC peering connection. You must Configure IP Access List Entries for all the virtual servers residing in the VPC. Cluster nodes remaining in the region are unaffected.
If you change your cluster's highest priority region or if MongoDB migrates oplog data to a different 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 the regions.
If you disable continuous cloud backup, Atlas will delete the continuous cloud backup history.
Use the following procedure to move nodes to a single-region cluster.
- You must also select a higher cluster tier. Atlas supports
M5clusters only when you increase the cluster tier.
- The available regions are a subset of the total supported regions for any given cloud service provider.
Use the following procedure to move nodes to one or more regions in an
M10 or larger multi-region cluster:
For a given region, click the currently selected Region and pick a new region from the drop-down list. If you modify the Preferred region, the Atlas cluster calls for one or more elections to select a new primary in the selected region. See Test Failover for instructions on testing your application response to a replica set election before changing the Preferred cluster.
To change the number of nodes Atlas deploys to a given region, increase or decrease the Number of Nodes value. the total number of nodes across the Preferred region and all Electable regions must be an odd number.