This post explains the immutable deployment process in AWS Elastic Beanstalk. Bobcares, as a part of our AWS Support Services, offers solutions to every AWS query that comes our way.

Immutable Deployment In AWS Elastic Beanstalk

A slow deployment method that makes sure that new instances of the app are always used. It avoids the updates of existing ones. In the event that the deployment is unsuccessful, it also provides a speedy and secure rollback. By using this method, Elastic Beanstalk deploys the app via an immutable update.

A second Auto Scaling group is started in the environment as part of an immutable update. Until the new instances pass health checks, the old version continues to serve traffic alongside the new version.

Updates to an immutable environment ensure that configuration changes that call for replacing instances are handled effectively and securely. The rollback procedure only needs to terminate an Auto Scaling group if an immutable environment update fails. On the other hand, a failed rolling update needs the execution of another rolling update to undo the changes.

How Immutable Deployment In AWS Elastic Beanstalk Is Performed?

Elastic Beanstalk makes a second, temporary Auto Scaling group behind the environment’s load balancer to hold the additional instances in order to complete an immutable environment update. Elastic Beanstalk first starts a single instance in the new group with the modified settings. Along with all of the other instances in the initial Auto Scaling group that is using the prior configuration, this instance delivers traffic.

Elastic Beanstalk launches further instances with the updated configuration, matching the number of instances operating in the first Auto Scaling group after the first instance passes health checks. Elastic Beanstalk terminates the temporary Auto Scaling group and the old instances once all of the new instances have successfully passed health checks and have been transferred to the original Auto Scaling group.

When the instances in the new Auto Scaling group begin serving requests and before the instances in the prior Auto Scaling group are ended, during an immutable environment update, the environment’s capacity temporarily doubles. So we must make sure we have the capacity to do an immutable environment update if the environment contains a lot of instances or the on-demand instance limit is low. Instead, we can think about employing rolling updates if we are close to the quota.

[Need assistance with another issue? We are just a click away.]

Conclusion

In addition to the instances running the older version of the application, immutable deployments in AWS Elastic Beanstalk start a full set of fresh instances running the new version in a different Auto Scaling group.