Guide: How to Automate AWS Snapshots With CloudWatch

AWS Elastic Block Store (EBS) service leverages persistent block storage to store Elastic Cloud Compute (EC2) instances. EC2 instances are virtual servers running on AWS environments. EBS is useful for running containerized applications, big data analytics, relational and non-relational databases, and more.

EBS enables you to take snapshots of your volumes to backup your data and prevent data loss. This article explains the basics of AWS EBS snapshots, including an example of how to automate your snapshots with CloudWatch.

AWS Snapshots Features

There are many useful EBS features you can use to optimize your cloud infrastructure.

Flexible Backup

AWS snapshots are incremental backups that can save you a lot of cloud storage costs. The snapshot creation process starts with a backup of the entire EBS volume. The following snapshot saves only the data that has changed since the initial backup, and indicates the location of the previous snapshots that include the unchanged data. This flexible backup process eliminates duplicate data duplicate in multiple snapshots.  

When you want to delete an old snapshot, AWS automatically pushes forward the old snapshot to the next subsequent snapshot and updates the existing references. This provides flexibility in the snapshot management process. You can remove backups from anywhere in the chain without affecting the functionality of others. 

Automated Backups

Snapshot automation can safely back up your data while saving time and effort. Snapshot scheduling and management are done with the Lifecycle Manager EBS service. This service is useful when you are using only EBS. You need to specify which volumes you want to be back up, the frequency of snapshots, and the backup time. 

However, consider using AWS Backup iIf you are using additional AWS services like Elastic File System (EFS), Relational Database Service (RDS), and AWS Storage Gateway. You can also automate EBS snapshots backup using the CLI, if you want more flexibility and control. The AWS CLI uses custom scripts to store snapshots in different services and regions, and with different permissions or encryption settings. 

Snapshot Sharing

You cannot create new volumes in region A from a snapshot stored in region B. However, you can share snapshots to other regions and then create new volumes. Snapshot sharing enables you to grow across geographic locations, migrate data centers, and set up disaster recovery plans.

You can even share snapshots with other accounts if you have the correct permissions. This is useful for third-party integrations, collaborative work, and open-source contributions. You can share unencrypted or encrypted snapshots if the other account has your Customer Managed Key (CMK).

Considerations for EBS Snapshot Automation

EBS enables you to create cost-efficient automated backups. However, you still have to understand the challenges of EBS automation to make the most of AWS:

• Scalability ━ frequent volume backups, and management of a large number of volumes requires a lot of time and resources. Automation enables you to leverage the scalability of the cloud, and grow your environment in a short period of time. 

• Dynamic environment ━ AWS automatically deploys and terminates old instances. Therefore, automation must be flexible to ensure the snapshots are up to date with the latest changes..

• Reliability ━ Ensure the reliability of automated backups when working with critical production volumes. Real-time error reporting systems can help you avoid potential pitfalls. 

AWS CloudWatch Events Concepts

You have to understand the following concepts before you start using CloudWatch to automate snapshots.

Events

AWS services generate events to indicate changes in their state. For instance, Amazon EC2 generates an event when the EC2 instance state changes from pending to running. AWS CloudTrail generates events when you make API calls. In addition, you can create custom application-level events and upload them to CloudWatch Events. You can also schedule event generation on a periodic basis.

Rules

The purpose of rules is to compare incoming events and direct them to targets for processing. A single rule can direct to multiple targets. The processing of events is done in parallel, but not in a specific order. This enables companies to search for and process only the relevant events. Rules can modify the JSON file sent to the target, by directing only particular parts or by overwriting it with a constant.

Targets

Targets are the resources you invoke when a rule is triggered. Targets can include AWS Lambda functions, Amazon EC2 instances,Amazon ECS tasks, Kinesis streams, and many more. Targets receive events in JSON format.

Automated Amazon EBS Snapshots Using CloudWatch Events

The following example creates an automated snapshot of EBS volume using CloudWatch. The example shows you how to create a snapshot every few minutes by choosing a fixed rate or creating a snapshot at a specific time of day using a cron expression.

Step 1: Create a Rule

Create scheduled snapshots using a rule. You can specify the schedule using rate expression or a cron expression. For more information, see Schedule Expressions for Rules

To create a rule:

1. Open the AWS console

2. Choose Events → Create Rule in the navigation pane.

3. Do the following for event source

• Choose Schedule

• Choose the snapshot rate and specify the schedule period. For instance five minutes. 

• Another option is to define a cron expression. For instance, every 10 minutes Sunday to Thursday.

      4. Choose “Add Target” and then select “EC2 Create Snapshot API call” to create targets. 

      5.Specify the volume ID of the targeted Amazon EBS volume

      6. Grants targets the required access permissions by choosing “Create a new role for this specific.                  resource”.

      7. Select “Configure details”.

      8. Choose a name and description for the rule.

      9. Select “Create rule”.

Step 2: Test the Rule

You can test your rule by viewing your first snapshot.

To verify rules:

1. Open the AWS console

2. Choose Elastic Block Store, Snapshots in the navigation pane.

3. Confirm that the first snapshot appears in the list

4. You can disable the rule to avoid taking additional snapshots when you are finished.

• Select Events, Rules, in the navigation pane

• Select Actions, Disable for the rule you want to disable

• Choose Disable when you are asked to confirm

Conclusion

Backups are an absolute must in any business environment. AWS backup automation enables you to save time on recurring tasks. Automation can also help you confirm that necessary tasks are done. You can automate your EBS snapshots in several different ways. The CloudWatch Events automation approach enables you to programmatically automate snapshots by using Lambda functions.