Choosing Regions and Availability Zones

Amazon operates advanced, highly available data centers. Although rare, failures can occur that affect the availability of instances that are in the same location. If you host all your instances in a single location that is affected by such a failure, none of your instances would be available. The following diagram shows an AWS Region with three Availability Zones.

It is important to remember that each Region is independent. Any Amazon DocumentDB activity that you initiate (for example, creating instances or listing available instances) runs only in your current default AWS Region. You can change the default Region on the console by setting the environment variable. Or you can override it by using the --region parameter in the AWS CLI. For more information, see Configuring the AWS Command Line Interface, specifically, the sections on environment variables and command line options.

When you create a cluster using the Amazon DocumentDB console, and you choose to create a replica in a different Availability Zone, Amazon DocumentDB creates two instances. It creates the primary instance in one Availability Zone and the replica instance in a different Availability Zone. The cluster volume is always replicated across three Availability Zones.

To create or work with an Amazon DocumentDB instance in a specific AWS Region, use the corresponding regional service endpoint.

Amazon DocumentDB is available in the following AWS Regions.

Regions Supported by Amazon DocumentDB

By default, the time zone for an Amazon DocumentDB cluster is Universal Time Coordinated (UTC).

For information on finding the connection endpoints for clusters and instances in a particular region, see .