Tags in ElastiCache are also known as cost allocation tags. They are a key-value pair which are associated with one ElastiCache resource. Both the key and the value are case sensitive. You can use the key of a tag to define a category, and the value of the tag can be an item in that category. For example, you can categorise which ElastiCache cluster is used for production and which ones are used for development categories. It is recommended to use a consistent set of tag keys to make it easier to track costs associated with your resources.
Also, 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. When you add, list, modify, copy, or remove a tag, the operation is applied only to the specified cluster.
The tag key is the required name of the tag. The key's string value can be from 1 to 128 Unicode characters long and cannot be prefixed with aws:.
The tag value is the optional value of the tag. The value's string value can be from 1 to 256 Unicode characters in length and cannot be prefixed with aws:.
An ElastiCache resource can have a maximum of 50 tags.
Values do not have to be unique in a tag set.
Cost allocation tags are applied to ElastiCache resources which are specified in CLI and API operations as an ARN.
Tags can be created by going to the ElastiCache dashboard, then choosing the specific cluster type. In our case we have chosen the Memcached cluster and use the button named Manage tags .
Clicking on the Manage tags button shown in the step above, we get a screen where we can add tag keys and their values. The value field is optional. To delete a tag, simply use the cross symbol. Click the button Apply Changes to create the actual tag.
Once the tags are applied, we can see them in the cluster details page as shown below.