Amazon ECS service action events - Amazon Elastic Container Service
Service action events with INFO event typeService action events with WARN event typeService action events with ERROR event type
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Amazon ECS service action events

Amazon ECS sends service action events with the detail type ECS Service Action. Unlike the container instance and task state change events, the service action events do not include a version number in the details response field. The following is an event pattern that is used to create an EventBridge rule for Amazon ECS service action events. For more information, see Creating an EventBridge Rule in the Amazon EventBridge User Guide.

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

Amazon ECS sends events with INFO, WARN, and ERROR event types. The following are the service action events.

Service action events with INFO event type

SERVICE_STEADY_STATE

The service is healthy and at the desired number of tasks, thus reaching a steady state. The service scheduler reports the status periodically, so you might receive this message multiple times.

TASKSET_STEADY_STATE

The task set is healthy and at the desired number of tasks, thus reaching a steady state.

CAPACITY_PROVIDER_STEADY_STATE

A capacity provider associated with a service reaches a steady state.

SERVICE_DESIRED_COUNT_UPDATED

When the service scheduler updates the computed desired count for a service or task set. This event is not sent when the desired count is manually updated by a user.

Service action events with WARN event type

SERVICE_TASK_START_IMPAIRED

The service is unable to consistently start tasks successfully.

SERVICE_DISCOVERY_INSTANCE_UNHEALTHY

A service using service discovery contains an unhealthy task. The service scheduler detects that a task within a service registry is unhealthy.

Service action events with ERROR event type

SERVICE_DAEMON_PLACEMENT_CONSTRAINT_VIOLATED

A task in a service using the DAEMON service scheduler strategy no longer meets the placement constraint strategy for the service.

ECS_OPERATION_THROTTLED

The service scheduler has been throttled due to the Amazon ECS API throttle limits.

SERVICE_DISCOVERY_OPERATION_THROTTLED

The service scheduler has been throttled due to the Amazon Cloud Map API throttle limits. This can occur on services configured to use service discovery.

SERVICE_TASK_PLACEMENT_FAILURE

The service scheduler is unable to place a task. The cause will be described in the reason field.

A common cause for this service event being generated is because of a lack of resources in the cluster to place the task. For example, not enough CPU or memory capacity on the available container instances or no container instances being available. Another common cause is when the Amazon ECS container agent is disconnected on the container instance, causing the scheduler to be unable to place the task.

SERVICE_TASK_CONFIGURATION_FAILURE

The service scheduler is unable to place a task due to a configuration error. The cause will be described in the reason field.

A common cause of this service event being generated is because tags were being applied to the service but the user or role had not opted in to the new Amazon Resource Name (ARN) format in the Region. For more information, see Amazon Resource Names (ARNs) and IDs. Another common cause is that Amazon ECS was unable to assume the task IAM role provided.

Example Service steady state event

Service steady state events are delivered in the following format. For more information about EventBridge parameters, see Events and Event Patterns in the Amazon EventBridge User Guide.

{
    "version": "0",
    "id": "af3c496d-f4a8-65d1-70f4-a69d52e9b584",
    "detail-type": "ECS Service Action",
    "source": "aws.ecs",
    "account": "111122223333",
    "time": "2019-11-19T19:27:22Z",
    "region": "us-west-2",
    "resources": [
        "arn:aws:ecs:us-west-2:111122223333:service/default/servicetest"
    ],
    "detail": {
        "eventType": "INFO",
        "eventName": "SERVICE_STEADY_STATE",
        "clusterArn": "arn:aws:ecs:us-west-2:111122223333:cluster/default",
        "createdAt": "2019-11-19T19:27:22.695Z"
    }
}
Example Capacity provider steady state event

Capacity provider steady state events are delivered in the following format.

{
    "version": "0",
    "id": "b9baa007-2f33-0eb1-5760-0d02a572d81f",
    "detail-type": "ECS Service Action",
    "source": "aws.ecs",
    "account": "111122223333",
    "time": "2019-11-19T19:37:00Z",
    "region": "us-west-2",
    "resources": [
        "arn:aws:ecs:us-west-2:111122223333:service/default/servicetest"
    ],
    "detail": {
        "eventType": "INFO",
        "eventName": "CAPACITY_PROVIDER_STEADY_STATE",
        "clusterArn": "arn:aws:ecs:us-west-2:111122223333:cluster/default",
        "capacityProviderArns": [
            "arn:aws:ecs:us-west-2:111122223333:capacity-provider/ASG-tutorial-capacity-provider"
        ],
        "createdAt": "2019-11-19T19:37:00.807Z"
    }
}
Example Service task start impaired event

Service task start impaired events are delivered in the following format.

{
    "version": "0",
    "id": "57c9506e-9d21-294c-d2fe-e8738da7e67d",
    "detail-type": "ECS Service Action",
    "source": "aws.ecs",
    "account": "111122223333",
    "time": "2019-11-19T19:55:38Z",
    "region": "us-west-2",
    "resources": [
        "arn:aws:ecs:us-west-2:111122223333:service/default/servicetest"
    ],
    "detail": {
        "eventType": "WARN",
        "eventName": "SERVICE_TASK_START_IMPAIRED",
        "clusterArn": "arn:aws:ecs:us-west-2:111122223333:cluster/default",
        "createdAt": "2019-11-19T19:55:38.725Z"
    }
}
Example Service task placement failure event

Service task placement failure events are delivered in the following format. For more information about EventBridge parameters, see Events and Event Patterns in the Amazon EventBridge User Guide.

In the following example, the task was attempting to use the FARGATE_SPOT capacity provider but the service scheduler was unable to acquire any Fargate Spot capacity.

{
    "version": "0",
    "id": "ddca6449-b258-46c0-8653-e0e3a6d0468b",
    "detail-type": "ECS Service Action",
    "source": "aws.ecs",
    "account": "111122223333",
    "time": "2019-11-19T19:55:38Z",
    "region": "us-west-2",
    "resources": [
        "arn:aws:ecs:us-west-2:111122223333:service/default/servicetest"
    ],
    "detail": {
        "eventType": "ERROR",
        "eventName": "SERVICE_TASK_PLACEMENT_FAILURE",
        "clusterArn": "arn:aws:ecs:us-west-2:111122223333:cluster/default",
        "capacityProviderArns": [
            "arn:aws:ecs:us-west-2:111122223333:capacity-provider/FARGATE_SPOT"
        ],
        "reason": "RESOURCE:FARGATE",
        "createdAt": "2019-11-06T19:09:33.087Z"
    }
}

In the following example for the EC2 launch type, the task was attempted to launch on the Container Instance 2dd1b186f39845a584488d2ef155c131 but the service scheduler was unable to place the task because of insufficient CPU.

{
  "version": "0",
  "id": "ddca6449-b258-46c0-8653-e0e3a6d0468b",
  "detail-type": "ECS Service Action",
  "source": "aws.ecs",
  "account": "111122223333",
  "time": "2019-11-19T19:55:38Z",
  "region": "us-west-2",
  "resources": [
    "arn:aws:ecs:us-west-2:111122223333:service/default/servicetest"
  ],
  "detail": {
    "eventType": "ERROR",
    "eventName": "SERVICE_TASK_PLACEMENT_FAILURE",
    "clusterArn": "arn:aws:ecs:us-west-2:111122223333:cluster/default",
    "containerInstanceArns": [
    "arn:aws:ecs:us-west-2:111122223333:container-instance/default/2dd1b186f39845a584488d2ef155c131"
    ],
    "reason": "RESOURCE:CPU",
    "createdAt": "2019-11-06T19:09:33.087Z"
  }
}