Amazon ECS introduces Early Success Criteria for service deployments
Amazon ECS now allows users to define when a rolling service deployment is considered successful using Early Success Criteria, enabling faster deployments and reduced blocking of dependent operations.
Amazon Elastic Container Service (Amazon ECS) has introduced Early Success Criteria for rolling service deployments, allowing users to specify when a deployment is deemed successful based on their operational needs. By configuring the healthy percent—the proportion of desired tasks that must be running and healthy—users can complete deployments sooner. For instance, with a desired count of 100 tasks and a healthy percent of 90%, the deployment is marked successful once 90 tasks are healthy, while the remaining tasks continue launching outside the deployment lifecycle. This feature is particularly useful for workloads with constrained capacity, such as GPU-accelerated inference workloads, where hardware availability can delay task launches.
Early Success Criteria also provides greater control over deployment rollback monitoring by allowing it to protect the deployment until the configured success criteria are met. Meanwhile, subsequent scale-out continues through regular service scaling. Users can further customize how Amazon ECS handles source service revision cleanup using two options: BLOCKING or DEFERRED. With BLOCKING, cleanup occurs before declaring success, while DEFERRED allows Amazon ECS to declare success upon meeting criteria and drain source revision tasks asynchronously outside the deployment.
The BLOCKING option ensures source revision cleanup completes before success is declared, which is useful for maintaining a clean state. In contrast, DEFERRED benefits services with active long-lived connections or task scale-in protection, as it allows source revision tasks to remain running without holding the deployment open. This flexibility helps prevent disruptions to ongoing operations while still enabling timely deployment completion.
The feature is now available with the rolling deployment strategy in all AWS Commercial and AWS GovCloud (US) Regions. Users can configure Early Success Criteria for new and existing Amazon ECS services through the AWS Management Console, AWS CLI, AWS SDKs, and infrastructure as code (IaC) tools. For additional details, users are directed to the official documentation.