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Amazon AWS

Synopsis

Atlas supports deploying clusters onto Amazon AWS. This page provides reference material related to Atlas cluster deployments on Amazon AWS.

Amazon Availability Zones

A given Amazon region includes a set number of independent availability zones. For regions that have at least three availability zones (3AZ), Atlas deploys clusters across three availability zones. For regions that only have two availability zones (2AZ), Atlas deploys clusters across two availability zones.

Atlas marks regions that support at least three availability zones as Recommended, as they provide higher availability as compared to other regions.

Note

The number of availability zones in a region has no affect on the number of nodes Atlas can deploy. MongoDB Atlas clusters are always made of replica sets with a minimum of three nodes.

For more information on the number of availability zones in a given region, see the Amazon documentation on global infrastructure.

For more information on Amazon AWS regions and availability zones, see the Amazon documentation on using regions and availability zones

Regions with at Least Three Availability Zones

Atlas clusters deployed in regions with at least three availability zones are split across three availability zones. For example, a three node replica set cluster would have one node deployed onto each availability zone.

A 3-node replica set deployed across a 3-availability zone AWS region.

3AZ clusters have higher availability compared to 2AZ clusters. However, not all regions support 3AZ clusters.

The Atlas Add New Cluster form marks regions that support 3AZ clusters as Recommended.

Regions with Only Two Availability Zones

Atlas clusters deployed in regions with two availability zones are split across the two availability zones. For example, a three node replica set cluster would have two nodes deployed to one availability zone and the remaining node deployed to the other availability zone.

A 3-node replica set deployed across a 2-availability zone AWS region.

2AZ clusters have a higher chance of loss of availability in the event of the loss of an availability zone than 3AZ clusters. However, where latency or location are a priority, a region that supports 2AZ clusters may be preferred.