Updating ElasticBeanstalk

EBS Deployment Policies

Elastic Beanstalk supports several options for processing deployments:

1. All at once
2. Rolling
3. Rolling with additional batch
4. Immutable

All At Once Deployment Updates

• Deploys the new version to all instances simultaneously
• All of your instances are out of service while the deployment takes place
• You will experience an outage while the deployment is taking place; not ideal for mission-critical production systems
• If the update fails, you need to roll back the changes by re-deploying the original version to all your instances

Rolling Deployment Updates

• Deploys the new version in batches
• Each batch of instance is taken out of service while the deployment takes place
• Your environment capacity will be reduced by the number of instances in a batch while the deployment takes place
• Not ideal for performance sensitive systems
• If the update fails, you need to perform additional rolling update to roll back the changes

Rolling with Additional Batch Updates

• Launches an additional batch of instances
• Deploys the new version in batches
• Maintains full capacity during the deployment process
• If the update fails, you need to perform an additional rolling update to roll back the changes

Immutable Updates

• Deploys the new version to a fresh group of instance in their own new autoscaling group
• When the new instances pass their health checks, they are moved to your existing auto scaling group; and finally, the old instances are terminated
• Maintains full capacity during the deployment process
• The impact of a failed update is far less and the rollback process requires only terminating the new auto scaling group
• Preferred option for Mission Critical production systems

Updating Elastic Beanstalk Exam Tips

• Remember the 4 different deployment approaches:
  • All at Once
    • Service interruption while you update the entire environment at once
    • To roll back, perform a further all at once upgrade
  • Rolling
    • Reduced capacity during deployment
    • To roll back, perform a further rolling update
  • Rolling with Additional Batch
    • Maintains full capacity
    • To roll back, perform a further rolling update
  • Immutable
    • Preferred option for mission critical production systems
    • Maintains full capacity
    • To roll back, just delete the new instances and autoscaling group