Managing Instance Classes

The instance class determines the computation and memory capacity of an Amazon DocumentDB (with MongoDB compatibility) instance. The instance class you need depends on your processing power and memory requirements.

Amazon DocumentDB supports the R4, R5, and T3 families of instance classes. These classes are current-generation instance classes that are optimized for memory-intensive applications. For the specifications on these classes, see Instance Class Specifications .

Determining an Instance Class

To determine the class of an instance, you can use the AWS Management Console or the describe-db-instances AWS CLI operation.

To determine the instance class for your cluster’s instances, complete the following steps in the console.

1. Sign in to the AWS Management Console, and open the Amazon DocumentDB console at https://console.aws.amazon.com/docdb.

2. In the navigation pane, choose Clusters to find the instance that you’re interested in.

   Tip

   If you don’t see the navigation pane on the left side of your screen, choose the menu icon () in the upper-left corner of the page.

3. In the Clusters navigation box, you’ll see the column Cluster Identifier. Your instances are listed under clusters, similar to the screenshot below.

   

4. In the list of instances, expand the cluster to find the instances you are interested in. Find the instance that you want. Then, look at the Size column of the instance’s row to see its instance class.

   In the following image, the instance class for instance robo3t is db.r5.4xlarge.

   ![

                       Screen shot showing a list of instances with 
                          their instance types.
                    ](/projects/DocumentDB-20201111-en/27d1c1bde23388a59c578947cc039aec.png)

To determine the class of an instance using the AWS CLI, use the describe-db-instances operation with the following parameters.

• --db-instance-identifier — Optional. Specifies the instance that you want to find the instance class for. If this parameter is omitted, describe-db-instances returns a description for up to 100 of your instances.

• --query — Optional. Specifies the members of the instance to include in the results. If this parameter is omitted, all instance members are returned.

The following example finds the instance name and class for the instance sample-instance-1.

For Linux, macOS, or Unix:

aws docdb describe-db-instances \
    --query 'DBInstances[*].[DBInstanceIdentifier,DBInstanceClass]' \
    --db-instance-identifier sample-instance-1

For Windows:

aws docdb describe-db-instances ^
    --query 'DBInstances[*].[DBInstanceIdentifier,DBInstanceClass]' ^
    --db-instance-identifier sample-instance-1

Output from this operation looks something like the following.

[
    [
        "sample-instance-1",
        "db.r5.large"
    ]

The following example finds the instance name and class for up to 100 Amazon DocumentDB instances.

For Linux, macOS, or Unix:

aws docdb describe-db-instances \
    --query 'DBInstances[*].[DBInstanceIdentifier,DBInstanceClass]' \
    --filter Name=engine,Values=docdb

For Windows:

aws docdb describe-db-instances ^
    --query 'DBInstances[*].[DBInstanceIdentifier,DBInstanceClass]' ^
    --filter Name=engine,Values=docdb

Output from this operation looks something like the following.

[
    [
        "sample-instance-1",
        "db.r5.large"
    ],
    [
        "sample-instance-2",
        "db.r5.large"
    ],
    [
        "sample-instance-3",
        "db.r5.4xlarge"
    ],
    [
        "sample-instance-4",
        "db.r5.4xlarge"
    ]
]

For more information, see Describing Amazon DocumentDB Instances.

Changing an Instance’s Class

You can change the instance class of your instance using the AWS Management Console or the AWS CLI. For more information, see Modifying an Amazon DocumentDB Instance.

Supported Instance Classes by Region

Amazon DocumentDB supports the following instance classes:

• R5—Latest generation of memory-optimized instances that provide up to 100% better performance over R4 instances for the same instance cost.

• R4—Previous generation of memory-optimized instances.

• T3—Latest-generation low cost burstable general-purpose instance type that provides a baseline level of CPU performance with the ability to burst CPU usage at any time for as long as required.

For detailed specifications on the instance classes, see Instance Class Specifications .

A particular instance class may or may not be supported in a given Region. The following table specifies which instance classes are supported by Amazon DocumentDB in each Region.

Instance Class Specifications

The following table provides details of the Amazon DocumentDB instance classes. You can find explanations for each table column below the table.