Manage an Amazon EMR Job - Amazon Step Functions
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Manage an Amazon EMR Job

This sample project demonstrates Amazon EMR and Amazon Step Functions integration.

It shows how to create an Amazon EMR cluster, add multiple steps and run them, and then terminate the cluster.

Important

Amazon EMR does not have a free pricing tier. Running the sample project will incur costs. You can find pricing information on the Amazon EMR pricing page. The availability of Amazon EMR service integration is subject to the availability of Amazon EMR APIs. Because of this, this sample project might not work correctly in some Amazon Regions. See the Amazon EMR documentation for limitations in special Regions.

Step 1: Create the State Machine and Provision Resources

  1. Open the Step Functions console and choose Create state machine.

  2. Type Manage an EMR job in the search box, and then choose Manage an EMR job from the search results that are returned.

  3. Choose Next to continue.

  4. Step Functions lists the Amazon Web Services used in the sample project you selected. It also shows a workflow graph for the sample project. Deploy this project to your Amazon Web Services account or use it as a starting point for building your own projects. Based on how you want to proceed, choose Run a demo or Build on it.

    This sample project deploys the following resources:

    • An Amazon S3 bucket

    • An Amazon EMR cluster

    • An Amazon Step Functions state machine

    • Related Amazon Identity and Access Management (IAM) roles

    The following image shows the workflow graph for the Manage an EMR job sample project:

    
          Workflow graph of the Manage an EMR job sample project.
  5. Choose Use template to continue with your selection.

  6. Do one of the following:

    • If you selected Build on it, Step Functions creates the workflow prototype for the sample project you selected. Step Functions doesn't deploy the resources listed in the workflow definition.

      In Workflow Studio's Design mode, drag and drop states from the States browser to continue building your workflow protoype. Or switch to the Code mode that provides an integrated code editor similar to VS Code for updating the Amazon States Language (ASL) definition of your state machine within the Step Functions console. For more information about using Workflow Studio to build your state machines, see Using Workflow Studio.

      Important

      Remember to update the placeholder Amazon Resource Name (ARN) for the resources used in the sample project before you run your workflow.

    • If you selected Run a demo, Step Functions creates a read-only sample project which uses an Amazon CloudFormation template to deploy the Amazon resources listed in that template to your Amazon Web Services account.

      Tip

      To view the state machine definition of the sample project, choose Code.

      When you're ready, choose Deploy and run to deploy the sample project and create the resources.

      It can take up to 10 minutes for these resources and related IAM permissions to be created. While your resources are being deployed, you can open the CloudFormation Stack ID link to see which resources are being provisioned.

      After all the resources in the sample project are created, you can see the new sample project listed on the State machines page.

      Important

      Standard charges may apply for each service used in the CloudFormation template.

Step 2: Run the state machine

  1. On the State machines page, choose your sample project.

  2. On the sample project page, choose Start execution.

  3. In the Start execution dialog box, do the following:

    1. (Optional) To identify your execution, you can specify a name for it in the Name box. By default, Step Functions generates a unique execution name automatically.

      Note

      Step Functions allows you to create names for state machines, executions, and activities, and labels that contain non-ASCII characters. These non-ASCII names don't work with Amazon CloudWatch. To ensure that you can track CloudWatch metrics, choose a name that uses only ASCII characters.

    2. (Optional) In the Input box, enter input values in JSON format to run your workflow.

      If you chose to Run a demo, you need not provide any execution input.

      Note

      If the demo project you deployed contains prepopulated execution input data, use that input to run the state machine.

    3. Choose Start execution.

    4. The Step Functions console directs you to a page that's titled with your execution ID. This page is known as the Execution Details page. On this page, you can review the execution results as the execution progresses or after it's complete.

      To review the execution results, choose individual states on the Graph view, and then choose the individual tabs on the Step details pane to view each state's details including input, output, and definition respectively. For details about the execution information you can view on the Execution Details page, see Execution Details page – Interface overview.

Example State Machine Code

The state machine in this sample project integrates with Amazon EMR by passing parameters directly to those resources. Browse through this example state machine to see how Step Functions uses a state machine to call the Amazon EMR task synchronously, waits for the task to succeed or fail, and terminates the cluster.

For more information about how Amazon Step Functions can control other Amazon services, see Using Amazon Step Functions with other services.

{ "Comment": "An example of the Amazon States Language for running jobs on Amazon EMR", "StartAt": "Create an EMR cluster", "States": { "Create an EMR cluster": { "Type": "Task", "Resource": "arn:<PARTITION>:states:::elasticmapreduce:createCluster.sync", "Parameters": { "Name": "ExampleCluster", "VisibleToAllUsers": true, "ReleaseLabel": "emr-5.26.0", "Applications": [ { "Name": "Hive" } ], "ServiceRole": "<EMR_SERVICE_ROLE>", "JobFlowRole": "<EMR_EC2_INSTANCE_PROFILE>", "LogUri": "s3://<EMR_LOG_S3_BUCKET>/logs/", "Instances": { "KeepJobFlowAliveWhenNoSteps": true, "InstanceFleets": [ { "Name": "MyMasterFleet", "InstanceFleetType": "MASTER", "TargetOnDemandCapacity": 1, "InstanceTypeConfigs": [ { "InstanceType": "m5.xlarge" } ] }, { "Name": "MyCoreFleet", "InstanceFleetType": "CORE", "TargetOnDemandCapacity": 1, "InstanceTypeConfigs": [ { "InstanceType": "m5.xlarge" } ] } ] } }, "ResultPath": "$.cluster", "Next": "Run first step" }, "Run first step": { "Type": "Task", "Resource": "arn:<PARTITION>:states:::elasticmapreduce:addStep.sync", "Parameters": { "ClusterId.$": "$.cluster.ClusterId", "Step": { "Name": "My first EMR step", "ActionOnFailure": "CONTINUE", "HadoopJarStep": { "Jar": "command-runner.jar", "Args": ["<COMMAND_ARGUMENTS>"] } } }, "Retry" : [ { "ErrorEquals": [ "States.ALL" ], "IntervalSeconds": 1, "MaxAttempts": 3, "BackoffRate": 2.0 } ], "ResultPath": "$.firstStep", "Next": "Run second step" }, "Run second step": { "Type": "Task", "Resource": "arn:<PARTITION>:states:::elasticmapreduce:addStep.sync", "Parameters": { "ClusterId.$": "$.cluster.ClusterId", "Step": { "Name": "My second EMR step", "ActionOnFailure": "CONTINUE", "HadoopJarStep": { "Jar": "command-runner.jar", "Args": ["<COMMAND_ARGUMENTS>"] } } }, "Retry" : [ { "ErrorEquals": [ "States.ALL" ], "IntervalSeconds": 1, "MaxAttempts": 3, "BackoffRate": 2.0 } ], "ResultPath": "$.secondStep", "Next": "Terminate Cluster" }, "Terminate Cluster": { "Type": "Task", "Resource": "arn:<PARTITION>:states:::elasticmapreduce:terminateCluster", "Parameters": { "ClusterId.$": "$.cluster.ClusterId" }, "End": true } } }

IAM Example

This example Amazon Identity and Access Management (IAM) policy generated by the sample project includes the least privilege necessary to execute the state machine and related resources. It's a best practice to include only those permissions that are necessary in your IAM policies.

{ "Version": "2012-10-17", "Statement": [ { "Effect": "Allow", "Action": [ "elasticmapreduce:RunJobFlow", "elasticmapreduce:DescribeCluster", "elasticmapreduce:TerminateJobFlows" ], "Resource": "*" }, { "Effect": "Allow", "Action": "iam:PassRole", "Resource": [ "arn:aws-cn:iam::123456789012:role/StepFunctionsSample-EMRJobManagement-EMRServiceRole-ANPAJ2UCCR6DPCEXAMPLE", "arn:aws-cn:iam::123456789012:role/StepFunctionsSample-EMRJobManagementWJALRXUTNFEMI-ANPAJ2UCCR6DPCEXAMPLE-EMREc2InstanceProfile-1ANPAJ2UCCR6DPCEXAMPLE" ] }, { "Effect": "Allow", "Action": [ "events:PutTargets", "events:PutRule", "events:DescribeRule" ], "Resource": [ "arn:aws-cn:events:sa-east-1:123456789012:rule/StepFunctionsGetEventForEMRRunJobFlowRule" ] } ] }

The following policy ensures that addStep has sufficient permissions.

{ "Version": "2012-10-17", "Statement": [ { "Effect": "Allow", "Action": [ "elasticmapreduce:AddJobFlowSteps", "elasticmapreduce:DescribeStep", "elasticmapreduce:CancelSteps" ], "Resource": "arn:aws:elasticmapreduce:*:*:cluster/*" }, { "Effect": "Allow", "Action": [ "events:PutTargets", "events:PutRule", "events:DescribeRule" ], "Resource": [ "arn:aws-cn:events:sa-east-1:123456789012:rule/StepFunctionsGetEventForEMRAddJobFlowStepsRule" ] } ] } }

For information about how to configure IAM when using Step Functions with other Amazon services, see IAM Policies for integrated services.