How to prevent downtime during AWS Elastic Beanstalk deployment of a new version of the app?

Question

My understanding of Elastic Beanstalk is that when you deploy a new version of your app, that it deploys it to the Amazon EC2 instances one at a time (if you have more than one). However, even with a minimum of two instances, my application incurs a short amount of downtime when I upload a new .war when it is deploying it, as if it is updating them both simultaneously. Is there a way I can ensure there is no downtime and that one instance is fully updated and accepting requests before the next starts: Here is how the events look. Note this is with zero load on the app, so it will only get worse with production traffic.

INFO

New application version was deployed to running EC2 instances.

ERROR

The application did not respond at the health check URL.

INFO

Waiting for 8 seconds while EC2 instances download the updated application version.

INFO

Deploying version SomethingMore to 2 instance(s).

Answer 1

One way to achieve this will be to use multiple environments. Expand your deployment procedure to support multiple environments.

An environment is basically a version that is deployed on AWS resources. There can only be a single version running on a single environment, however, we can run multiple environments containing same versions at the same time.