Run AWS Batch workloads with Step Functions

You can integrate Step Functions with AWS Batch to run batch computing workloads in the AWS cloud. This page lists the supported AWS Batch APIs and provides an example Task state to perform a batch-processing task.

To learn about integrating with AWS services in Step Functions, see Integrating services and Passing parameters to a service API in Step Functions.

Key features of Optimized AWS Batch integration

• The Run a Job (.sync) integration pattern is available.

Note that there are no optimizations for the Request Response or Wait for a Callback with Task Token integration patterns.

The following shows an example Task state that submits an AWS Batch job and waits for it to complete. Many of the arguments shown are optional.

"Submit Batch Job": {
    "Type": "Task",
    "Resource": "arn:aws:states:::batch:submitJob.sync",
    "Arguments": {
        "JobName": "BATCH_NAME",
        "JobQueue": "BATCH_QUEUE_ARN",
        "JobDefinition": "BATCH_JOB_DEFINITION_ARN",
        "ArrayProperties": {
        "Size": 10
        },
        "ContainerOverrides": {
        "ResourceRequirements": [
            {
            "Type": "VCPU",
            "Value": "4"
            }
        ]
        },
        "DependsOn": [
        {
            "JobId": "myJobId",
            "Type": "SEQUENTIAL"
        }
        ],
        "PropagateTags": true,
        "Parameters": {
        "Key1": "value1",
        "Key2": 100
        },
        "RetryStrategy": {
        "Attempts": 1
        },
        "Tags": {
        "Tag": "TAG"
        },
        "Timeout": {
        "AttemptDurationSeconds": 10
        }
    }
}

Optimized AWS Batch APIs:

• SubmitJob

  • Request syntax

  • Supported parameters:

    • ArrayProperties

    • ContainerOverrides

    • DependsOn

    • JobDefinition

    • JobName

    • JobQueue

    • Parameters

    • RetryStrategy

    • Timeout

    • Tags

  • Response syntax

Parameters in Step Functions are expressed in PascalCase

Even if the native service API is in camelCase, for example the API action startSyncExecution, you specify parameters in PascalCase, such as: StateMachineArn.

IAM policies for calling AWS Batch

The following example templates show how AWS Step Functions generates IAM policies based on the resources in your state machine definition. For more information, see How Step Functions generates IAM policies for integrated services and Discover service integration patterns in Step Functions.

Because job ids for SubmitJob and TerminateJob are generated and therefore only known at runtime, you cannot create a policy that restricts access based on a specific resource.

Tip for fine grained access

To add fine grained access to SubmitJob and TerminateJob, consider using tags for jobs and creating a policy that limits access based on your tags. In addition, the job queue, definition, and consumable resources can be restricted for SubmitJob using known resources.

Run a Job (.sync)

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "batch:SubmitJob",
                "batch:DescribeJobs",
                "batch:TerminateJob"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "events:PutTargets",
                "events:PutRule",
                "events:DescribeRule"
            ],
            "Resource": [
               "arn:aws:events:[[region]]:[[accountId]]:rule/StepFunctionsGetEventsForBatchJobsRule"
            ]
        }
    ]
}
        

Request Response

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "batch:SubmitJob"
            ],
            "Resource": "*"
        }
    ]
}