# Required resources for Amazon ECS canary deployments
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To use a canary deployment with managed traffic shifting, your service must use one of the following features:
+ Elastic Load Balancing
+ Service Connect

The following list provides a high-level overview of what you need to configure for Amazon ECS canary deployments:
+ Your service uses an Application Load Balancer, Network Load Balancer, or Service Connect. Configure the appropriate resources.
  + Application Load Balancer - For more information, see [Application Load Balancer resources for blue/green, linear, and canary deployments](alb-resources-for-blue-green.md).
  + Network Load Balancer - For more information, see [Network Load Balancer resources for Amazon ECS blue/green, linear and canary deployments](nlb-resources-for-blue-green.md).
  + Service Connect - For more information, see [Service Connect resources for Amazon ECS blue/green, linear, and canary deployments](service-connect-blue-green.md).
+ Set the service deployment controller to `ECS`.
+ Configure the deployment strategy as `canary` in your service definition.
+ Optionally, configure additional parameters such as:
  + Bake time for the new deployment
  + The percentage of traffic to route to the new service revision during the canary phase. 
  + The duration to wait during the canary phase before shifting the remaining traffic to the new service revision. 
  + CloudWatch alarms for automatic rollback
  + Deployment lifecycle hooks (Lambda functions or pause hooks that run at specified deployment stages)

## Best practices
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Follow these best practices for successful Amazon ECS lcanary deployments:
+ **Ensure your application can handle both service revisions running simultaneously.**
+ **Plan for sufficient cluster capacity to handle both service revisions during deployment.**
+ **Test your rollback procedures before implementing them in production.**
+ Configure appropriate health checks that accurately reflect your application's health.
+ Set a bake time that allows sufficient testing of the green deployment.
+ Implement CloudWatch alarms to automatically detect issues and trigger rollbacks.
+ Use lifecycle hooks to perform automated testing at each deployment stage.
+ Start with small canary percentages (5-10%) to minimize impact if issues occur.
+ Set appropriate evaluation periods that allow sufficient time for meaningful performance data collection.
+ Implement comprehensive monitoring with CloudWatch alarms for automated rollback triggers.
+ Configure health checks that accurately reflect your application's readiness and functionality.
+ Monitor both technical metrics (response time, error rate) and business metrics during evaluation.
+ Ensure your application can handle traffic splitting without session or state issues.
+ Plan rollback procedures and test them regularly to ensure they work when needed.
+ Schedule canary deployments during business hours when teams can monitor and respond.
+ Validate changes thoroughly in staging environments before canary deployment.
+ Document clear procedures for manual intervention and rollback decisions.