Daemon events

Amazon ECS sends daemon events to to provide visibility into daemon task management and deployment lifecycle changes. You can use these events to monitor daemon health, track deployment progress, and trigger automated workflows.

Amazon ECS supports the following daemon event types:

• Daemon service action events - Events related to daemon task placement and startup issues.

• Daemon deployment state change events - Events related to daemon deployment lifecycle transitions.

To learn how to create rules for these events, see Creating rules for daemon events.

Daemon service action events

Amazon ECS sends daemon service action events with the detail type ECS Daemon Service Action. These events notify you when Amazon ECS encounters issues starting daemon tasks on your container instances.

DAEMON_TASK_START_IMPAIRED

Amazon ECS sends the DAEMON_TASK_START_IMPAIRED event when it is unable to successfully start a daemon task on a container instance. The event includes a failureType field that indicates the cause of the failure:

• TASK_FAILED_TO_RUN - The daemon task was created but failed to reach RUNNING status. Common causes include container image pull failures, container health check failures, or essential container exits. The taskArn field is present in the event.

• TASK_CREATION_FAILED - The daemon task could not be created on the container instance. Common causes include insufficient CPU, memory, or other resources on the instance. The taskArn field is not present in the event because no task was created.

Example: TASK_FAILED_TO_RUN event

The following event shows a daemon task that was created but failed to reach RUNNING status due to a container image pull failure.

{
    "version": "0",
    "id": "12345678-1234-1234-1234-123456789012",
    "detail-type": "ECS Daemon Service Action",
    "source": "aws.ecs",
    "account": "123456789012",
    "time": "2026-03-24T12:00:00Z",
    "region": "us-west-2",
    "resources": [
        "arn:aws:ecs:us-west-2:123456789012:task/my-cluster/a1b2c3d4e5f6"
    ],
    "detail": {
        "eventType": "WARNING",
        "eventName": "DAEMON_TASK_START_IMPAIRED",
        "clusterArn": "arn:aws:ecs:us-west-2:123456789012:cluster/my-cluster",
        "containerInstanceArn": "arn:aws:ecs:us-west-2:123456789012:container-instance/my-cluster/a1b2c3d4e5f6",
        "taskArn": "arn:aws:ecs:us-west-2:123456789012:task/my-cluster/a1b2c3d4e5f6",
        "daemonRevisionArn": "arn:aws:ecs:us-west-2:123456789012:daemon-revision/my-cluster/my-daemon/a1b2c3d4-e5f6-7890-abcd-ef1234567890",
        "capacityProviderName": "my-capacity-provider",
        "daemonArn": "arn:aws:ecs:us-west-2:123456789012:daemon/my-cluster/my-daemon",
        "daemonTaskDefinitionArn": "arn:aws:ecs:us-west-2:123456789012:daemon-task-definition/my-daemon-td:1",
        "failureType": "TASK_FAILED_TO_RUN",
        "createdAt": "2026-03-24T12:00:00.000Z",
        "reason": "Task failed to reach RUNNING status: CannotPullContainerError: pull image manifest has been retried 5 time(s)"
    }
}

Example: TASK_CREATION_FAILED event

The following event shows a daemon task that could not be created on the container instance due to insufficient CPU resources. The taskArn field is not present because no task was created.

{
    "version": "0",
    "id": "87654321-4321-4321-4321-210987654321",
    "detail-type": "ECS Daemon Service Action",
    "source": "aws.ecs",
    "account": "123456789012",
    "time": "2026-03-24T12:01:00Z",
    "region": "us-west-2",
    "resources": [],
    "detail": {
        "eventType": "WARNING",
        "eventName": "DAEMON_TASK_START_IMPAIRED",
        "clusterArn": "arn:aws:ecs:us-west-2:123456789012:cluster/my-cluster",
        "containerInstanceArn": "arn:aws:ecs:us-west-2:123456789012:container-instance/my-cluster/b2c3d4e5f6a7",
        "daemonRevisionArn": "arn:aws:ecs:us-west-2:123456789012:daemon-revision/my-cluster/my-daemon/a1b2c3d4-e5f6-7890-abcd-ef1234567890",
        "capacityProviderName": "my-capacity-provider",
        "daemonArn": "arn:aws:ecs:us-west-2:123456789012:daemon/my-cluster/my-daemon",
        "daemonTaskDefinitionArn": "arn:aws:ecs:us-west-2:123456789012:daemon-task-definition/my-daemon-td:1",
        "failureType": "TASK_CREATION_FAILED",
        "createdAt": "2026-03-24T12:01:00.000Z",
        "reason": "RESOURCE:CPU - Unable to place daemon task on container instance: insufficient CPU"
    }
}

Daemon deployment state change events

Amazon ECS sends daemon deployment state change events with the detail type ECS Daemon Deployment State Change. Amazon ECS emits these events each time the state of a daemon deployment changes.

Deployment state change event types

Amazon ECS categorizes deployment state change events by the following event types:

INFO events

• DAEMON_DEPLOYMENT_PENDING - Amazon ECS has initiated a daemon deployment.

• DAEMON_DEPLOYMENT_IN_PROGRESS - Amazon ECS has started the deployment and is actively replacing daemon tasks.

• DAEMON_DEPLOYMENT_SUCCESSFUL - Amazon ECS has successfully completed the deployment with all daemon tasks running and healthy.

• DAEMON_DEPLOYMENT_STOPPED - Amazon ECS has stopped the deployment. This occurs when a deployment has failed or has been replaced by a new deployment.

• DAEMON_DEPLOYMENT_STOP_REQUESTED - Amazon ECS has stopped the deployment from moving forward and will now start to roll back.

• DAEMON_DEPLOYMENT_ROLLBACK_IN_PROGRESS - Amazon ECS has initiated a rollback due to deployment failure or circuit breaker trigger.

• DAEMON_DEPLOYMENT_ROLLBACK_SUCCESSFUL - Amazon ECS has successfully completed the deployment rollback.

ERROR events

• DAEMON_DEPLOYMENT_ROLLBACK_FAILED - Amazon ECS was unable to complete the deployment rollback.

Example: Deployment pending event

The following event shows a daemon deployment that Amazon ECS has initiated.

{
    "version": "0",
    "id": "3329f79b-3dca-07f8-b1c2-5fe99f0b5e87",
    "detail-type": "ECS Daemon Deployment State Change",
    "source": "aws.ecs",
    "account": "111122223333",
    "time": "2026-03-05T15:54:41Z",
    "region": "us-west-2",
    "resources": [
        "arn:aws:ecs:us-west-2:111122223333:daemon/my-cluster/my-daemon"
    ],
    "detail": {
        "eventType": "INFO",
        "eventName": "DAEMON_DEPLOYMENT_PENDING",
        "clusterArn": "arn:aws:ecs:us-west-2:111122223333:cluster/my-cluster",
        "daemonArn": "arn:aws:ecs:us-west-2:111122223333:daemon/my-cluster/my-daemon",
        "daemonDeploymentArn": "arn:aws:ecs:us-west-2:111122223333:daemon-deployment/my-cluster/my-daemon/0EYSiB0qap8xf0N76FsbE",
        "targetDaemonRevisionArn": "arn:aws:ecs:us-west-2:111122223333:daemon-revision/my-cluster/my-daemon/85707969-3732-4b6a-a37d-5cefddd7d7dd",
        "updatedAt": "2026-03-05T15:54:41.618059641Z"
    }
}

Creating rules for daemon events

You can create rules to receive notifications when daemon events occur. For more information about creating rules, see Creating a rule in the Amazon EventBridge User Guide.

The following example event patterns show how to filter daemon events.

Example: Match all daemon service action events

{
    "source": ["aws.ecs"],
    "detail-type": ["ECS Daemon Service Action"]
}

Example: Match a specific failure type

{
    "source": ["aws.ecs"],
    "detail-type": ["ECS Daemon Service Action"],
    "detail": {
        "eventName": ["DAEMON_TASK_START_IMPAIRED"],
        "failureType": ["TASK_CREATION_FAILED"]
    }
}

Example: Match events for a specific cluster

{
    "source": ["aws.ecs"],
    "detail-type": ["ECS Daemon Service Action"],
    "detail": {
        "eventName": ["DAEMON_TASK_START_IMPAIRED"],
        "clusterArn": ["arn:aws:ecs:us-west-2:123456789012:cluster/my-cluster"]
    }
}

Example: Match all deployment state change events

{
    "source": ["aws.ecs"],
    "detail-type": ["ECS Daemon Deployment State Change"]
}