Amazon ECS Managed Daemons
Amazon ECS Managed Daemons enable you to deploy and manage software agents, such as security, observability, and networking agents, across your container infrastructure on Amazon ECS Managed Instances. Managed Daemons decouple daemon lifecycle management from application operations. You can deploy, update, and monitor agents independently, without redeploying workloads or coordinating changes across services.
How Managed Daemons work
To use Managed Daemons, first register a daemon task definition. A daemon task definition is a template that describes the containers that form a daemon. After you register a daemon task definition, create a daemon and associate it with a cluster and one or more Amazon ECS Managed Instances capacity providers. Amazon ECS then ensures that exactly one daemon task runs on every Amazon EC2 instance provisioned through those capacity providers.
Daemons do not launch instances independently. When you run an application task on a
Amazon ECS Managed Instances capacity provider, Amazon ECS provisions an Amazon EC2 instance, starts the
daemon task first, and only then transitions the application task to
RUNNING. This ordering guarantees that cross-cutting functions like
logging, tracing, and metrics collection are operational before your application begins
processing requests.
Daemons are essential for instance health. If a daemon task stops, Amazon ECS automatically drains and replaces that container instance. This auto-repair behavior ensures reliable daemon coverage across all instances without manual intervention.
When you update a daemon to a new task definition revision, Amazon ECS performs a rolling deployment across all instances in the associated capacity providers. During the deployment, Amazon ECS drains a configurable percentage of instances simultaneously, provisions replacement instances with the updated daemon, and replaces your Amazon ECS service tasks automatically. Amazon ECS provides built-in circuit breaker protection. You can configure a bake time and CloudWatch alarms so that Amazon ECS monitors the deployment after it updates all instances and automatically rolls back if issues arise.
Key benefits
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Decoupled lifecycle management - Update daemons independently from application deployments.
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Guaranteed coverage - Amazon ECS ensures daemon tasks start before application tasks on every instance, so cross-cutting functions are always available.
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Reliable version updates - When you update a daemon version, Amazon ECS rolls it out across all instances in the associated capacity providers, with built-in circuit breaker protection and automatic rollback to ensure every instance runs the target revision.
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Improved resource utilization - Running a single daemon task per instance eliminates the sidecar-per-task model, reducing resource overhead across your cluster.
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Automatic instance repair - If a daemon task stops or becomes unhealthy, Amazon ECS automatically drains and replaces that container instance. This maintains reliable daemon coverage without manual intervention.
Note
Amazon ECS offers a DAEMON scheduling strategy for Amazon ECS services for the Amazon EC2 launch type. Managed Daemons is a new capability built for Amazon ECS Managed Instances to simplify daemon deployments and provide stronger daemon coverage guarantees.
Getting started
To get started, register a daemon task definition specifying your container image, then create a daemon with associated capacity providers in your cluster. You can use the AWS Management Console, AWS CLI, CloudFormation, or AWS SDKs. For step-by-step instructions, see Creating and managing daemons.
