Perform scaling updates

Scaling updates adjust the capacity of your compute environment by adding or removing instances. This is the fastest update strategy and doesn't require replacing existing instances. Scaling updates work with any service role type and allocation strategy, making them the most flexible update option.

Changes that trigger a scaling update

When you modify only the following settings, AWS Batch performs a scaling update. If you modify any of these settings along with other compute environment settings, AWS Batch performs an infrastructure update instead.

The following settings trigger scaling updates when modified exclusively:

• desiredvCpus – Sets the target number of vCPUs for the environment.

• maxvCpus – Defines the maximum number of vCPUs that can be launched.

• minvCpus – Specifies the minimum number of vCPUs to maintain.

For Fargate compute environments, you can also modify these settings for scaling updates:

• securityGroupIds – Security group IDs for the compute environment.

• subnets – Subnets for the compute environment.

Note

We recommend not using desiredvCpus to initiate a scaling update as AWS Batch will dynamically adjust desiredvCpus. Instead you should update minvCpus.

When updating desiredvCpus, the value must be between minvCpus and maxvCpus. The new value must be greater than or equal to the current desiredvCpus. For more information, see Error message when you update the desiredvCpus setting.

Important

If you modify any of these scaling settings together with other compute environment settings (such as instance types, AMI IDs, or launch templates), AWS Batch performs an infrastructure update instead of a scaling update. Infrastructure updates take longer and may replace existing instances.

Performing scaling updates using the AWS Management Console

1. Open the AWS Batch console at https://console.aws.amazon.com/batch/.

2. In the navigation pane, choose Environments and then the Compute environments tab.

3. Select the compute environment to update.

4. Choose Actions and then Edit.

5. Modify one or more of the settings that support scaling updates. For example:

   • For Minimum vCPUs, enter the minimum number of vCPUs.

   • For Desired vCPUs, enter the desired number of vCPUs.

   • For Maximum vCPUs, enter the maximum number of vCPUs.

6. Choose Save changes.

7. Monitor the compute environment status. The update should complete quickly since it only involves scaling operations.

Performing scaling updates using the AWS CLI

Use the update-compute-environment command to perform scaling updates. The following two examples demonstrate common scaling operations. You can modify one or more of the following settings that support scaling updates

• This example updates the desired, minimum, and maximum vCPUs:

  aws batch update-compute-environment \
      --compute-environment your-compute-environment-name \
      --compute-resources minvCpus=2,maxvCpus=8

Monitoring scaling updates

Monitor your scaling updates using the AWS Batch console to view the compute environment status and check instance count and vCPU metrics. You can also use the AWS CLI with the describe-compute-environments command to check status and monitor instance counts and vCPU values.