A leading Financial firm has deployed its stock trading application on Amazon EC2 instance in an Auto Scaling Group behind Application Load Balancer. The software Team has developed a new version of this application & are seeking your support to deploy this new version to production. The Operations head has instructed for a deployment using Elastic Beanstalk which should not have any service impact on the application & should be able to quickly rollback in case of failure during deployment. Also post-deployment, initially only 10% of traffic should be diverted to the new version.
Which of the deployment policies can be used to meet the requirement?

Answer options:

A.Use Traffic splitting deployment policy.
B.Use Rolling deployment policy.
C.Use Immutable deployment policy.
D.Use Rolling with an additional batch deployment policy.

Correct Answer: A
In the Traffic splitting deployment policy, AWS Elastic Beanstalk launches a full set of EC2 Instance in a new Auto Scaling group for the new version of the application. Post deployment, a certain percentage of traffic can be diverted to a new setup. This policy is easy for rollback. As in case of any failure, traffic can be diverted to the old version which is not modified during deployment of the new version. In the above case, the firm is looking for a new application version to be deployed without any service impact & with 10% traffic to the new version with quick rollback. For this requirement, a traffic splitting deployment policy is best suited.
Option B is incorrect as although this deployment is suitable for deployment without any service impact to the existing application. Still, it’s not suitable for a quick rollback in case of deployment failure.
Option C is incorrect as with this deployment option, traffic splitting between old & new versions is not possible.
Option D is incorrect as this deployment option is not suitable for quick rollback.
For more information on deploying applications with deployment policies with AWS Elastic Beanstalk, refer to the following URLs,
https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features.rolling-version-deploy.html
https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features.deploy-existing-version.html