All at once
- Deploys to all instances simultaneously.
- You will experience a total outage.
- Not ideal for mission-critical production system.
- Rolling back: another outage to get back to the previous version
Rolling Deployment Policy
- Deploys the new version in batches
- Each batch is taken out of service while the deployment takes place
- You env capacity will be reduced by the number of instances in a batch while the deployment takes places.
- Not ideal for performance sensitive system.
- Rolling back: perform an additional rolling update to roll back the changes
Rolling with Additional Batch
- Launches an additional batch of instances.
- Deploys the new version in batches
- Maintains full capacity throughout the deployment
- Rolling back: perform an additional rolling update to roll back the changes
Immutable Deployments
- Deploy the new version to a fresh group of instances
- Only when the new instances pass their health checks, should the old instances be terminated.
- This is the preferred approach for mission cirtical system.
- Rollback: Just delete the new instances
