Skip to main content

Tagging Along in AWS: EC2 Tags in Action

(Update) We’ve recently published a new post on AWS Tagging Best Practices where we review what to keep in mind when tagging your resources and how tags are important for your business.

One of the most under-appreciated features of EC2 I’ve found is tagging. Almost any resource in EC2 can be tagged via a key-value pair, including volumes, instances, and snapshots. There are a few restrictions, for example, the length of the EC2 tags themselves, and you cannot use some AWS reserved keywords. But, as usual, the best place to confirm this is in the official AWS documentation.

In this post, I’d like to demonstrate a potential use case for tagging, and a practical example of how to access these tags programmatically via the Java AWS SDK.

EC2 Tagging

In practice, the most likely tag you might have encountered when starting out with EC2 is the (non-compulsory) name tag as presented by the launch wizard:
Tagging step in EC2 instance creation
An important concept to keep in mind is that tags do not carry semantic meaning, which gives you free rein to interpret the values as you deem fit.
So let’s get our hands dirty with an example…

EC2 tags use case and a potential solution

Let’s say you’re running two EC2 on-demand instances on your AWS account. One of them hosts your live server, and the other runs your staging environment for testing. On the AWS Management Console, it might look something like this:
Like the good, responsible engineer that you are, you’d soon realize the need to periodically back up the block devices (storage) on your live environment in case it gets corrupted, or an inexperienced engineer in your team accidentally messes up the configuration beyond repair. You could, of course, do it manually from the management console. However, if your number of instances start growing, a much better solution would be to do this programmatically somehow and execute that code as often as you feel necessary via a cron job or a scheduled task.

Via tags, you could approach it this way:

  1. Create a tag with the same key (for example ‘Stack’) on both instances. On your live instance(s) give it the value ‘Production’, and on the staging ones give it the value ‘Stage’.
  2. Via the AWS SDK, get a list of the instances on your account, and if the tag with the key value ‘Stack’ has the value ‘Production’, you know you can take a snapshot of that instance’s storage volume(s).

 Creating Tags

With this strategy in mind, we can go over to action.

On the management console, select your live instance, select the ‘Tags’ tab and click on ‘Add/Edit Tags’.
In the Key field, type ‘Stack’ and in the Value type ‘Production’. You should end up with something that looks like this:
environment_mc tags_production
For your staging instance, create another tag with the same Key value, but in the Value field, type ‘Staging’ instead.

That’s it. You’re set up for the programming part. We’re using Java for this example, for which Amazon generously provided an API to interact their services.

AWS Java SDK tag iteration

Provided that your access keys have been configured correctly, you should be able to authenticate your SDK session successfully to allow access to your resources. Remember to set the region as well:

    private static final String STACK_TAG_KEYNAME = "Stack";
    private static final SimpleDateFormat sdf = //To date your backups
            new SimpleDateFormat("yyyy-MM-dd_HH_mm_ss");
    public static void main(String[] args) {
        AWSCredentials credentials = null;
        log = LogFactory.getLog(SimpleLog.class);"Starting EC2 live backups");
        try {
            credentials = new ProfileCredentialsProvider()
        } catch (Exception e) {
            throw new AmazonClientException(
                    "Cannot load the credentials from the "
                    + "credential profiles file. "
                    + "Please make sure that your "
                    + "credentials file is at the correct "
                    + "location (~/.aws/credentials), and is in valid format.",
        ec2 = new AmazonEC2Client(credentials);

Getting access to all the instances (reserved and otherwise) is pretty straightforward. We then check each instance for a tag key and value that matches our criteria to identify the ones we’re interested in backing up:

       //Gets all reservations for your region
        Iterator vReservations = ec2.describeInstances()
        List vInstancesToBackUp = new ArrayList();
        //Step through all the reservations...
        Reservation vResItem = null;
        while (vReservations.hasNext()) {
            //For each reservation, get the instances
            vResItem =;
            Iterator vInstances = vResItem.getInstances().iterator();
            //For each instance, get the tags associated with it.
            while (vInstances.hasNext()) {
                Instance vInstanceItem =;
                List pTags = vInstanceItem.getTags();
                Iterator vIt = pTags.iterator();
                while (vIt.hasNext()) {
                    Tag item =;
                    //if the tag key macthes and the value we're looking for, we return
                    if (item.getKey().equals("Stack")
                     && item.getValue().equals("Production")) {
        }"Number of instances to back up:" + vInstancesToBackUp.size());

When we’ve got the list of instances we’re interested in, we then create a snapshot of the block devices on that instance. We’ll use the instance name in the description of the snapshot to confirm that we’ve backed up the correct instance:

        for (Instance item : vInstancesToBackUp) {
            List devices = item.getBlockDeviceMappings();
            //For each block device, take a snapshot
            for (InstanceBlockDeviceMapping blockMapping : devices) {
      "Creating snapshot for device " + blockMapping.getDeviceName());
                CreateSnapshotRequest csr = new CreateSnapshotRequest(blockMapping.
                        getEbs().getVolumeId(), "SnapshotOf_" +
                        getInstanceName(item) + " on " + sdf.format(new Date()));
                CreateSnapshotResult result = ec2.createSnapshot(csr);
      "Snapshot ID created="+result.getSnapshot().getSnapshotId());

If everything goes well, when executed this code should output the following:

Oct 13, 2014 9:52:51 PM org.apache.commons.logging.impl.SimpleLog main
INFO: Starting EC2 live backups
Oct 13, 2014 9:52:54 PM org.apache.commons.logging.impl.SimpleLog main
INFO: Number of instances to back up:1
Oct 13, 2014 9:52:54 PM org.apache.commons.logging.impl.SimpleLog main
INFO: Creating snapshot for device /dev/sda1
Oct 13, 2014 9:52:54 PM org.apache.commons.logging.impl.SimpleLog main
INFO: Snapshot ID created=snap-3506c2c8

Note the snapshot id returned is snap-3506c2c8. If we go back to the management console, expand the Elastic Block Store node and click on Snapshots, you should see your newly created snapshot there. Note the live instances name in the description field, that is proof that we snapped the correct instance:

EC2 Snaphsot image
Snapshot view

You can use this snapshot to restore your storage volume to a previous version.


We’ve seen but one of the potential applications of tags. Using their semantic neutrality, their usage is of course not only limited to create volume snapshots, but also grouping billing cost centers more effectively, or whatever organizational application you can think of. Happy tagging!

Written by

Charles van der Wath

Related Posts

Sanket Dangi
— February 11, 2019

WaitCondition Controls the Pace of AWS CloudFormation Templates

AWS's WaitCondition can be used with CloudFormation templates to ensure required resources are running.As you may already be aware, AWS CloudFormation is used for infrastructure automation by allowing you to write JSON templates to automatically install, configure, and bootstrap your ...

Read more
  • AWS
  • formation
Andrew Larkin
— January 24, 2019

The 9 AWS Certifications: Which is Right for You and Your Team?

As companies increasingly shift workloads to the public cloud, cloud computing has moved from a nice-to-have to a core competency in the enterprise. This shift requires a new set of skills to design, deploy, and manage applications in cloud computing.As the market leader and most ma...

Read more
  • AWS
  • AWS certifications
Andrew Larkin
— November 28, 2018

Two New EC2 Instance Types Announced at AWS re:Invent 2018 – Monday Night Live

The announcements at re:Invent just keep on coming! Let’s look at what benefits these two new EC2 instance types offer and how these two new instances could be of benefit to you. If you're not too familiar with Amazon EC2, you might want to familiarize yourself by creating your first Am...

Read more
  • AWS
  • EC2
  • re:Invent 2018
Guy Hummel
— November 21, 2018

Google Cloud Certification: Preparation and Prerequisites

Google Cloud Platform (GCP) has evolved from being a niche player to a serious competitor to Amazon Web Services and Microsoft Azure. In 2018, research firm Gartner placed Google in the Leaders quadrant in its Magic Quadrant for Cloud Infrastructure as a Service for the first time. In t...

Read more
  • AWS
  • Azure
  • Google Cloud
Khash Nakhostin
Khash Nakhostin
— November 13, 2018

Understanding AWS VPC Egress Filtering Methods

In order to understand AWS VPC egress filtering methods, you first need to understand that security on AWS is governed by a shared responsibility model where both vendor and subscriber have various operational responsibilities. AWS assumes responsibility for the underlying infrastructur...

Read more
  • Aviatrix
  • AWS
  • VPC
Jeremy Cook
— November 10, 2018

S3 FTP: Build a Reliable and Inexpensive FTP Server Using Amazon’s S3

Is it possible to create an S3 FTP file backup/transfer solution, minimizing associated file storage and capacity planning administration headache?FTP (File Transfer Protocol) is a fast and convenient way to transfer large files over the Internet. You might, at some point, have conf...

Read more
  • Amazon S3
  • AWS
Guy Hummel
— October 18, 2018

Microservices Architecture: Advantages and Drawbacks

Microservices are a way of breaking large software projects into loosely coupled modules, which communicate with each other through simple Application Programming Interfaces (APIs).Microservices have become increasingly popular over the past few years. The modular architectural style,...

Read more
  • AWS
  • Microservices
Stuart Scott
— October 2, 2018

What Are Best Practices for Tagging AWS Resources?

There are many use cases for tags, but what are the best practices for tagging AWS resources? In order for your organization to effectively manage resources (and your monthly AWS bill), you need to implement and adopt a thoughtful tagging strategy that makes sense for your business. The...

Read more
  • AWS
  • cost optimization
Stuart Scott
— September 26, 2018

How to Optimize Amazon S3 Performance

Amazon S3 is the most common storage options for many organizations, being object storage it is used for a wide variety of data types, from the smallest objects to huge datasets. All in all, Amazon S3 is a great service to store a wide scope of data types in a highly available and resil...

Read more
  • Amazon S3
  • AWS
Cloud Academy Team
— September 18, 2018

How to Optimize Cloud Costs with Spot Instances: New on Cloud Academy

One of the main promises of cloud computing is access to nearly endless capacity. However, it doesn’t come cheap. With the introduction of Spot Instances for Amazon Web Services’ Elastic Compute Cloud (AWS EC2) in 2009, spot instances have been a way for major cloud providers to sell sp...

Read more
  • AWS
  • Azure
  • Google Cloud
  • SpotInst
Guy Hummel and Jeremy Cook
— August 23, 2018

What are the Benefits of Machine Learning in the Cloud?

A Comparison of Machine Learning Services on AWS, Azure, and Google CloudArtificial intelligence and machine learning are steadily making their way into enterprise applications in areas such as customer support, fraud detection, and business intelligence. There is every reason to beli...

Read more
  • AWS
  • Azure
  • Google Cloud
  • Machine Learning
Stuart Scott
— August 17, 2018

How to Use AWS CLI

The AWS Command Line Interface (CLI) is for managing your AWS services from a terminal session on your own client, allowing you to control and configure multiple AWS services.So you’ve been using AWS for awhile and finally feel comfortable clicking your way through all the services....

Read more
  • AWS