# Tag and categorize Amazon EMR cluster resources
It can be convenient to categorize your AWS resources in different ways; for example, by purpose, owner, or environment. You can achieve this in Amazon EMR by assigning custom metadata to your Amazon EMR clusters using tags. A tag consists of a key and a value, both of which you define. For Amazon EMR, the cluster is the resource-level that you can tag. For example, you could define a set of tags for your account's clusters that helps you track each cluster's owner or identify a production cluster versus a testing cluster. We recommend that you create a consistent set of tags to meet your organization requirements.
When you add a tag to an Amazon EMR cluster, the tag is also propagated to each active Amazon EC2 instance associated with the cluster. Similarly, when you remove a tag from an Amazon EMR cluster, that tag is removed from each associated active Amazon EC2 instance.
**Important**
Use the Amazon EMR console or CLI to manage tags on Amazon EC2 instances that are part of a cluster instead of the Amazon EC2 console or CLI, because changes that you make in Amazon EC2 do not synchronize back to the Amazon EMR tagging system.
You can identify an Amazon EC2 instance that is part of an Amazon EMR cluster by looking for the following system tags. In this example, *CORE* is the value for the instance group role and *j-12345678* is an example job flow (cluster) identifier value:
+ aws:elasticmapreduce:instance-group-role=*CORE*
+ aws:elasticmapreduce:job-flow-id=*j-12345678*
**Note**
Amazon EMR and Amazon EC2 interpret your tags as a string of characters with no semantic meaning.
You can work with tags using the AWS Management Console, the CLI, and the API.
You can add tags when creating a new Amazon EMR cluster and you can add, edit, or remove tags from a running Amazon EMR cluster. Editing a tag is a concept that applies to the Amazon EMR console, however using the CLI and API, to edit a tag you remove the old tag and add a new one. You can edit tag keys and values, and you can remove tags from a resource at any time a cluster is running. However, you cannot add, edit, or remove tags from a terminated cluster or terminated instances which were previously associated with a cluster that is still active. In addition, you can set a tag's value to the empty string, but you can't set a tag's value to null.
If you're using AWS Identity and Access Management (IAM) with your Amazon EC2 instances for resource-based permissions by tag, your IAM policies are applied to tags that Amazon EMR propagates to a cluster's Amazon EC2 instances. For Amazon EMR tags to propagate to your Amazon EC2 instances, your IAM policy for Amazon EC2 needs to allow permissions to call the Amazon EC2 CreateTags and DeleteTags APIs. Also, propagated tags can affect your Amazon EC2's resource-based permissions. Tags propagated to Amazon EC2 can be read as conditions in your IAM policy, just like other Amazon EC2 tags. Keep your IAM policy in mind when adding tags to your Amazon EMR clusters to avoid a users having incorrect permissions for a cluster. To avoid problems, make sure that your IAM policies do not include conditions on tags that you also plan to use on your Amazon EMR clusters. For more information, see [Controlling access to Amazon EC2 resources](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/UsingIAM.html).
# Restrictions that apply to tagging resources in Amazon EMR
The following basic restrictions apply to tags:
+ Restrictions that apply to Amazon EC2 resources apply to Amazon EMR as well. For more information, see [https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Using_Tags.html#tag-restrictions](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Using_Tags.html#tag-restrictions).
+ Do not use the `aws:` prefix in tag names and values because it is reserved for AWS use. In addition, you cannot edit or delete tag names or values with this prefix.
+ You cannot change or edit tags on a terminated cluster.
+ A tag value can be an empty string, but not null. In addition, a tag key cannot be an empty string.
+ Keys and values can contain any alphabetic character in any language, any numeric character, white spaces, invisible separators, and the following symbols: \$1 . : / = \$1 - @
For more information about tagging using the AWS Management Console, see [Working with tags in the console](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Using_Tags.html#Using_Tags_Console) in the *Amazon EC2 User Guide*. For more information about tagging using the Amazon EC2API or command line, see [API and CLI overview](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Using_Tags.html#Using_Tags_CLI) in the *Amazon EC2 User Guide*.
# Tag Amazon EMR resources for billing
You can use tags for organizing your AWS bill to reflect your own cost structure. To do this, sign up to get your AWS account bill with tag key values included. You can then organize your billing information by tag key values, to see the cost of your combined resources. Although Amazon EMR and Amazon EC2 have different billing statements, the tags on each cluster are also placed on each associated instance so you can use tags to link related Amazon EMR and Amazon EC2 costs.
For example, you can tag several resources with a specific application name, and then organize your billing information to see the total cost of that application across several services. For more information, see [Cost allocation and tagging](https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/allocation.html) in the *AWS Billing User Guide*.
# Add tags to an Amazon EMR cluster
You can add tags to a cluster when you create it.
------
#### [ Console ]
**To add tags when you create a cluster with the new console**
1. Sign in to the AWS Management Console, and open the Amazon EMR console at [https://console.aws.amazon.com/emr](https://console.aws.amazon.com/emr).
1. Under **EMR on EC2** in the left navigation pane, choose **Clusters**, and then choose **Create cluster**.
1. Under **Tags**, choose **Add new tag**. Specify a tag in the **Key** field. Optionally, specify a tag in the **Value** field.
1. Choose any other options that apply to your cluster.
1. To launch your cluster, choose **Create cluster**.
------
#### [ AWS CLI ]
**To add tags when you create a cluster with the the AWS CLI**
The following example demonstrates how to add a tag to a new cluster using the AWS CLI. To add tags when you create a cluster, type the `create-cluster` subcommand with the `--tags` parameter.
+ To add a tag named *costCenter* with key value *marketing* when you create a cluster, type the following command and replace *myKey* with the name of your EC2 key pair.
```
aws emr create-cluster --name "Test cluster" --release-label emr-4.0.0 --applications Name=Hadoop Name=Hive Name=Pig --tags "costCenter=marketing" --use-default-roles --ec2-attributes KeyName=myKey --instance-type m5.xlarge --instance-count 3
```
When you specify the instance count without using the `--instance-groups` parameter, a single Master node is launched, and the remaining instances are launched as core nodes. All nodes will use the instance type specified in the command.
**Note**
If you have not previously created the default EMR service role and EC2 instance profile, type aws `emr create-default-roles` to create them before typing the `create-cluster` subcommand.
For more information on using Amazon EMR commands in the AWS CLI, see [https://docs.aws.amazon.com/cli/latest/reference/emr](https://docs.aws.amazon.com/cli/latest/reference/emr).
------
You can also add tags to an existing cluster.
------
#### [ Console ]
**To add tags to an existing cluster with the new console**
1. Sign in to the AWS Management Console, and open the Amazon EMR console at [https://console.aws.amazon.com/emr](https://console.aws.amazon.com/emr).
1. Under **EMR on EC2** in the left navigation pane, choose **Clusters**, and select the cluster that you want to update.
1. On the **Tags** tab on the cluster details page, select **Manage tags**. Specify a tag in the **Key** field. Optionally, specify a tag in the **Value** field.
1. Select **Save changes**. The **Tags** tab updates with the new number of tags that you have on your cluster. For example, if you now have two tags, the label of your tab is **Tags (2)**.
------
#### [ AWS CLI ]
**To add tags to a running cluster with the AWS CLI**
+ Enter the `add-tags` subcommand with the `--tag` parameter to assign tags to the cluster ID. You can find the cluster ID using the console or the `list-clusters` command. The `add-tags` subcommand currently accepts only one resource ID.
For example, to add two tags to a running cluster one with a key named *costCenter* with a value of *marketing* and another named *other* with a value of *accounting*, enter the following command and replace *j-KT4XXXXXXXX1NM* with your cluster ID.
```
aws emr add-tags --resource-id j-KT4XXXXXXXX1NM --tag "costCenter=marketing" --tag "other=accounting"
```
Note that when tags are added using the AWS CLI, there's no output from the command. For more information on using Amazon EMR commands in the AWS CLI, see [https://docs.aws.amazon.com/cli/latest/reference/emr](https://docs.aws.amazon.com/cli/latest/reference/emr).
------
# View tags on an Amazon EMR cluster
If you want to see all tags associated with a cluster, you can view them with the console or the AWS CLI.
------
#### [ Console ]
**To view tags on a cluster with the new console**
1. Sign in to the AWS Management Console, and open the Amazon EMR console at [https://console.aws.amazon.com/emr](https://console.aws.amazon.com/emr).
1. Under **EMR on EC2** in the left navigation pane, choose **Clusters**, and select the cluster that you want to update.
1. To view all of your tags, select the **Tags** tab on the cluster details page.
------
#### [ AWS CLI ]
**To view tags on a cluster with the AWS CLI**
To view the tags on a cluster using the AWS CLI, type the `describe-cluster` subcommand with the `--query` parameter.
+ To view a cluster's tags, type the following command and replace *j-KT4XXXXXXXX1NM* with your cluster ID.
```
1. aws emr describe-cluster --cluster-id j-KT4XXXXXX1NM --query Cluster.Tags
```
The output displays all the tag information about the cluster similar to the following:
```
Value: accounting Value: marketing
Key: other Key: costCenter
```
For more information on using Amazon EMR commands in the AWS CLI, see [https://docs.aws.amazon.com/cli/latest/reference/emr](https://docs.aws.amazon.com/cli/latest/reference/emr).
------
# Remove tags from an Amazon EMR cluster
If you no longer need a tag, you can remove it from the cluster.
------
#### [ Console ]
**To remove tags on a cluster with the new console**
1. Sign in to the AWS Management Console, and open the Amazon EMR console at [https://console.aws.amazon.com/emr](https://console.aws.amazon.com/emr).
1. Under **EMR on EC2** in the left navigation pane, choose **Clusters**, and select the cluster that you want to update.
1. On the **Tags** tab on the cluster details page, select **Manage tags**.
1. Choose **Remove** for each key-value pair that you want to remove.
1. Choose **Save changes**.
------
#### [ AWS CLI ]
**To remove tags on a cluster with the AWS CLI**
Type the `remove-tags` subcommand with the `--tag-keys` parameter. When removing a tag, only the key name is required.
+ To remove a tag from a cluster, type the following command and replace *j-KT4XXXXXXXX1NM* with your cluster ID.
```
aws emr remove-tags --resource-id j-KT4XXXXXX1NM --tag-keys "costCenter"
```
**Note**
You cannot currently remove multiple tags using a single command.
For more information on using Amazon EMR commands in the AWS CLI, see [https://docs.aws.amazon.com/cli/latest/reference/emr](https://docs.aws.amazon.com/cli/latest/reference/emr).
------