One of the most efficient tools to truly understand what is happening with your cloud resources are Tags.
So, what are tags and how should you use them to get the best results?
Tags are Meta-data added to a resource in the cloud. Tags are written as – Key : Value     

You can define both the Key and Value anyway you would like but it is recommended to use a name that reflects the item. For example, the Key can be “Owner” and the Value would be the name of the person in charge of that resource.
Currently, AWS limits you to 50 Tags per Resource. Tagging is a critical tool to help us understand the use of each resource.

For example, a resource could be a server. Assuming we have hundreds of servers, without proper tagging we would not be able to identify the purpose of a specific one. To avoid this, it is recommended that each server should have a Tag to indicate several details of that particular resource. 

Tags can be added both during the resources’ creation and with an existing resource, they can be added or modified at any time.

Change/creation of Tags for an existing server. 

EC2 Tags

Adding Tags while creating a new server.

One of the most common and crucial tags is the tag ‘Name’ (giving a resource an identifiable and unique name).  While creating a server, you can click to add a name and Amazon will automatically add a Key and give you the option to add a Name value. As most servers use external disks (EBS) it is recommended that you add the Tags on both the server and the disk. 

It’s a good practice to require a defined set of tags whenever you add a new server and to not allow the creation of these servers without the required information. 

Based on our extensive experience with AWS we recommend always adding the following tags:
1. Owner
2. Purpose (DB, Jenkins, Project name and etc.)
3. Department
4. Cost Center
5. env
6. Project
7. Shutdown time (if known)

Utilizing the env Tag gives you a greater understanding of the environment that you are working in. Pileus utilizes this tag to give accurate recommendations to improve the environment that your servers are working in. Pileus provides recommendations that are relevant to both the actual production environments and for development and testing.