AWS Certified Developer Exam Notes – Beanstalk

Elastic Beanstalk

What is Elastic Beanstalk?

  • Elastic Beanstalk is a managed service for deploying the application. It relies on CloudFormation. 
  • There is no additional charge for Elastic Beanstalk.
  • It handles capacity, load balancing, scaling, monitoring
  • Can store at most 1000 app versions
    • Use lifecycle policy to phase out older versions.
      • It is based in time or space.
      • Cannot delete used versions.
  • You can clone an environment with Beanstalk Cloning (data is not preserved)
  • Setup HTTPS: Load SSL certification to Load Balancer
    • Can be done from console or code (ebextentions)
  • Ability to use Custom Platform (Advanced)
    • Define from scratch the OS and the scripts that Beanstalk run.
    • To create it you need to use the Packer software (create AMIs)
  • The database will be deleted in case we delete the environment. Perhaps you want to create the database outside beanstalk.
    • For dev/test use Beanstalk to create the database. For production use a separate database.

Source Bundle

  • ZIP or WAR file (you can include multiple WAR files inside your ZIP file)
  • Not exceed 512 MB
  • Not include a parent folder or top-level directory (subdirectories are fine)
  • Optional: For a worker application that processes periodic background tasks, the source bundle must also include a cron.yaml file.



  • Two types of environments.
    • Web Server: listen and process HTTP
    • Worker environment: Background process apps
  • If the Beanstalk application performs operations or workflows that take a long time to complete, you can offload those tasks to a dedicated worker environment.

Change load balancer after the creation

You need to perform migration

    1. Create new environment, with same configuration, but with another LB
    2. Deploy application in new environment
    3. Shift traffic from old to new

Deployment Modes

  • Single Instance – Great for dev
  • HA with Load Balancer – Great for prod
  • Deployment Options for Updates
    • All at once
      • Fastest but with downtime
    • Rolling
      • Few instances at a time (bucket or batch)
      • You set the bucket size (for example 2 out of 4 instances).
      • First 2 out of 4 will be updated, and when healthy the rest will be updated.
      • There is a point in time where both versions are running. 
      • No additional costs
    • Rolling with additional batches
      • Same with rolling, but spins up new instances 
      • Deploy new instances for example 2 extra, 6 in total.
      • After deploying the new instances, perform a normal rolling update to the old. It keeps the existing instances.
      • Good for production 
      • Small additional cost
    • Immutable
      • Spin up new instances in new ASG, deploy there and swap all the instances when healthy
      • Longest deployment and higher additional cost
      • Spin up new ASG with the new version in parallel with the old. Easy rollbacks.
      • In the end merge the two ASGs and terminate the old version applications.
    • Canary testing – Traffic Splitting



  • Placed in .ebextensions/ folder in the root folder of your app
  • YAML / JSON format
  • .config extensions (for example .ebextensions/xray-daemon.config)
  • You can use CloudFormation in this folder 

BeanStalk with Docker

  • For Single Docker Container it does not user ECS, but docker launched on EC2
  • Multi Docker Container creates ECS Cluster, EC2 instances run by ECS, LB, Task definitions