# ADVREL04-BP02 Deploy new code or resources in staggered phases, separated by sufficient time, to verify that the changes are successful
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 Implement gradual, phased deployments to minimize risks and service impacts when updating systems. 

## Implementation guidance
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 When deploying new code or resources, it is possible for unintended results to occur. Various deployment strategies can be used to reduce frequency and service impact. 

 By making changes through a blue/green deployment methodology, you can significantly reduce the impact of any potential issues and avoid downtime. 

 When a blue/green deployment isn't possible, a rolling deployment methodology should be used to reduce the number of resources being modified simultaneously. With a rolling deployment, changes are made in small batches, with a pre-determined amount of buffer time between batches. If an issue occurs with the deployment, the unchanged resources can continue handling traffic, avoiding downtime. 

## Key AWS services
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+  [AWS CloudFormation](https://aws.amazon.com/cloudformation/) 
+  [Amazon Elastic Container Service (ECS)](https://aws.amazon.com/ecs/) 

## Resources
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+  [Blue/Green Deployments on AWS](https://docs.aws.amazon.com/whitepapers/latest/blue-green-deployments/welcome.html) 
+  [Rolling deployments](https://docs.aws.amazon.com/whitepapers/latest/overview-deployment-options/rolling-deployments.html) 
+  [Deployment methods](Users/jblatch/Downloads/•%20https:/docs.aws.amazon.com/whitepapers/latest/practicing-continuous-integration-continuous-delivery/deployment-methods.html)