# Run AWS Batch workloads with Step Functions
<a name="connect-batch"></a>

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](integrate-services.md) and [Passing parameters to a service API in Step Functions](connect-parameters.md).

**Key features of Optimized AWS Batch integration**  
The [Run a Job (.sync)](connect-to-resource.md#connect-sync) integration pattern is available.
Note that there are no specific optimizations for the [Request Response](connect-to-resource.md#connect-default) or [Wait for a Callback with Task Token](connect-to-resource.md#connect-wait-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,
        "Arguments": {
        "Key1": "value1",
        "Key2": 100
        },
        "RetryStrategy": {
        "Attempts": 1
        },
        "Tags": {
        "Tag": "TAG"
        },
        "Timeout": {
        "AttemptDurationSeconds": 10
        }
    }
}
```

## Optimized AWS Batch APIs:
<a name="connect-batch-api"></a>
+ [https://docs.aws.amazon.com/batch/latest/APIReference/API_SubmitJob.html](https://docs.aws.amazon.com/batch/latest/APIReference/API_SubmitJob.html)

**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
<a name="batch-iam"></a>

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](service-integration-iam-templates.md) and [Discover service integration patterns in Step Functions](connect-to-resource.md).

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:us-east-1:123456789012:rule/StepFunctionsGetEventsForBatchJobsRule"
            ]
        }
    ]
}
```

------
#### [ Request Response ]

****  

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

------