# Adding steps to an Amazon EMR cluster with the AWS CLI
<a name="add-step-cli"></a>

The following procedures demonstrate how to add steps to a newly created cluster and to a running cluster with the AWS CLI. Both examples use the `--steps` subcommand to add steps to the cluster. 

**To add steps during cluster creation**
+ Type the following command to create a cluster and add an Apache Pig step. Make sure to replace *`myKey`* with the name of your Amazon EC2 key pair.

  ```
  1. aws emr create-cluster --name "Test cluster" \
  2. --applications Name=Spark \
  3. --use-default-roles \
  4. --ec2-attributes KeyName=myKey \
  5. --instance-groups InstanceGroupType=PRIMARY,InstanceCount=1,InstanceType=m5.xlarge InstanceGroupType=CORE,InstanceCount=2,InstanceType=m5.xlarge \
  6. --steps '[{"Args":["spark-submit","--deploy-mode","cluster","--class","org.apache.spark.examples.SparkPi","/usr/lib/spark/examples/jars/spark-examples.jar","5"],"Type":"CUSTOM_JAR","ActionOnFailure":"CONTINUE","Jar":"command-runner.jar","Properties":"","Name":"Spark application"}]'
  ```
**Note**  
The list of arguments changes depending on the type of step.

  By default, the step concurrency level is `1`. You can set the step concurrency level with the `StepConcurrencyLevel` parameter when you create a cluster. 

  The output is a cluster identifier similar to the following. 

  ```
  1. {
  2.     "ClusterId": "j-2AXXXXXXGAPLF"
  3. }
  ```

**To add a step to a running cluster**
+ Type the following command to add a step to a running cluster. Replace `j-2AXXXXXXGAPLF` with your own cluster ID.

  ```
  aws emr add-steps --cluster-id j-2AXXXXXXGAPLF \
  --steps '[{"Args":["spark-submit","--deploy-mode","cluster","--class","org.apache.spark.examples.SparkPi","/usr/lib/spark/examples/jars/spark-examples.jar","5"],"Type":"CUSTOM_JAR","ActionOnFailure":"CONTINUE","Jar":"command-runner.jar","Properties":"","Name":"Spark application"}]'
  ```

   The output is a step identifier similar to the following.

  ```
  1. {
  2.     "StepIds": [
  3. 	"s-Y9XXXXXXAPMD"
  4.     ]
  5. }
  ```

**To modify the StepConcurrencyLevel in a running cluster**

1. In a running cluster, you can modify the `StepConcurrencyLevel` with the `ModifyCluster` API. For example, type the following command to increase the `StepConcurrencyLevel` to `10`. Replace `j-2AXXXXXXGAPLF` with your cluster ID.

   ```
   aws emr modify-cluster --cluster-id j-2AXXXXXXGAPLF --step-concurrency-level 10
   ```

1. The output is similar to the following.

   ```
   {
   "StepConcurrencyLevel": 10
   }
   ```

For more information on using Amazon EMR commands in the AWS CLI, see the [AWS CLI Command Reference](https://docs.aws.amazon.com/cli/latest/reference/emr).