Managing Instance Classes - Amazon DocumentDB

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, R6G, T3, and T4G 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.

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:

  • R6G—Latest generation of memory-optimized instances powered by Arm-based AWS Graviton2 processors that provide up to 30% better performance over R5 instances at 5% cheaper cost. Graviton instance classes are supported on the 4.0.0 engine only.

  • R5—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.

  • T4G—Latest-generation low cost burstable general-purpose instance type powered by Arm-based AWS Graviton2 processors that provides a baseline level of CPU performance, delivering up to 35% better price performance over T3 instances and ideal for running applications with moderate CPU usage that experience temporary spikes in usage. Graviton instance classes are supported on the 4.0.0 engine only.

  • T3—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.

Supported instance classes by Region
Instance Classes
Region R6G R5 R4 T4G T3

US East (Ohio)

Supported

Supported

Supported

Supported

Supported

US East (N. Virginia)

Supported

Supported

Supported

Supported

Supported

US West (Oregon)

Supported

Supported

Supported

Supported

Supported

South America (São Paulo)

Supported

Supported

Supported

Supported

Asia Pacific (Mumbai)

Supported

Supported

Supported

Supported

Asia Pacific (Seoul)

Supported

Supported

Supported

Supported

Asia Pacific (Sydney)

Supported

Supported

Supported

Supported

Asia Pacific (Singapore)

Supported

Supported

Supported

Supported

Asia Pacific (Tokyo)

Supported

Supported

Supported

Supported

Canada (Central)

Supported

Supported

Supported

Supported

Europe (Frankfurt)

Supported

Supported

Supported

Supported

Europe (Ireland)

Supported

Supported

Supported

Supported

Supported

Europe (London)

Supported

Supported

Supported

Supported

Europe (Milan)

Supported

Supported

Supported

Supported

Europe (Paris)

Supported

Supported

Supported

Supported

China (Beijing) Region

Supported

Supported

Supported

Supported

China (Ningxia)

Supported

Supported

Supported

Supported

AWS GovCloud (US)

Supported

Supported

Supported

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.

Supported Amazon DocumentDB instance classes
Instance class vCPU1 Memory (GiB)2 Max. bandwidth (Mbps)3 Network performance4 Supporting Engines5
R6G – Current Generation Memory-Optimized Instance Class based on Graviton2
db.r6g.large 2 16 Up to 4,750 Up to 10 Gbps 4.0.0 only
db.r6g.xlarge 4 32 Up to 4,750 Up to 10 Gbps 4.0.0 only
db.r6g.2xlarge 8 64 Up to 4,750 Up to 10 Gbps 4.0.0 only
db.r6g.4xlarge 16 128 4,750 Up to 10 Gbps 4.0.0 only
db.r6g.8xlarge 32 256 9,000 12 Gbps 4.0.0 only
db.r6g.12xlarge 48 384 13,500 20 Gbps 4.0.0 only
db.r6g.16xlarge 64 512 19,000 25 Gbps 4.0.0 only
R5 – Previous Generation Memory-Optimized Instance Class
db.r5.large 2 16 Up to 3,500 Up to 10 Gbps 3.6.0 and 4.0.0
db.r5.xlarge 4 32 Up to 3,500 Up to 10 Gbps 3.6.0 and 4.0.0
db.r5.2xlarge 8 64 Up to 3,500 Up to 10 Gbps 3.6.0 and 4.0.0
db.r5.4xlarge 16 128 3,500 Up to 10 Gbps 3.6.0 and 4.0.0
db.r5.8xlarge 32 256 6,800 10 Gbps 3.6.0 and 4.0.0
db.r5.12xlarge 48 384 7,000 10 Gbps 3.6.0 and 4.0.0
db.r5.16xlarge 64 512 13,600 20 Gbps 3.6.0 and 4.0.0
db.r5.24xlarge 96 768 14,000 25 Gbps 3.6.0 and 4.0.0
R4 – Previous Generation Memory-Optimized Instance Class
db.r4.large 2 15.25 437 Up to 10 Gbps 3.6.0 only
db.r4.xlarge 4 30.5 875 Up to 10 Gbps 3.6.0 only
db.r4.2xlarge 8 61 875 Up to 10 Gbps 3.6.0 only
db.r4.4xlarge 16 122 875 Up to 10 Gbps 3.6.0 only
db.r4.8xlarge 32 244 875 10 Gbps 3.6.0 only
db.r4.16xlarge 64 488 14,000 25 Gbps 3.6.0 only
T4G – Latest Generation Burstable Performance Instance Classes based on Graviton2
db.t4g.medium 2 4 Up to 2,085 Up to 5 Gbps 4.0.0 only
T3 – Previous Generation Burstable Performance Instance Classes
db.t3.medium 2 4 Up to 1,536 Up to 5 Gbps 3.6.0 and 4.0.0
  1. vCPU — The number of virtual central processing units (CPUs). A virtual CPU is a unit of capacity that you can use to compare instance classes. Instead of purchasing or leasing a particular processor to use for several months or years, you are renting capacity by the hour. Our goal is to provide a consistent amount of CPU capacity no matter what the actual underlying hardware.

  2. Memory (GiB) — The RAM, in gigabytes, that is allocated to the instance. There is often a consistent ratio between memory and vCPU.

  3. Max. bandwidth (Mbps) — The maximum bandwidth in megabits per second. Divide by 8 to get the expected throughput in megabytes per second.

  4. Network performance — The network speed relative to other instance classes.

  5. Supporting Engines — The Amazon DocumentDB enigines that support the instance class.