HealthCheck - Amazon Elastic Container Service

HealthCheck

An object representing a container health check. Health check parameters that are specified in a container definition override any Docker health checks that exist in the container image (such as those specified in a parent image or from the image's Dockerfile).

You can view the health status of both individual containers and a task with the DescribeTasks API operation or when viewing the task details in the console.

The following describes the possible healthStatus values for a container:

  • HEALTHY-The container health check has passed successfully.

  • UNHEALTHY-The container health check has failed.

  • UNKNOWN-The container health check is being evaluated or there is no container health check defined.

The following describes the possible healthStatus values for a task. The container health check status of nonessential containers do not have an effect on the health status of a task.

  • HEALTHY-All essential containers within the task have passed their health checks.

  • UNHEALTHY-One or more essential containers have failed their health check.

  • UNKNOWN-The essential containers within the task are still having their health checks evaluated or there are no container health checks defined.

If a task is run manually, and not as part of a service, the task will continue its lifecycle regardless of its health status. For tasks that are part of a service, if the task reports as unhealthy then the task will be stopped and the service scheduler will replace it.

The following are notes about container health check support:

  • Container health checks require version 1.17.0 or greater of the Amazon ECS container agent. For more information, see Updating the Amazon ECS Container Agent.

  • Container health checks are supported for Fargate tasks if you are using platform version 1.1.0 or greater. For more information, see AWS Fargate Platform Versions.

  • Container health checks are not supported for tasks that are part of a service that is configured to use a Classic Load Balancer.

Contents

command

A string array representing the command that the container runs to determine if it is healthy. The string array must start with CMD to execute the command arguments directly, or CMD-SHELL to run the command with the container's default shell. For example:

[ "CMD-SHELL", "curl -f http://localhost/ || exit 1" ]

An exit code of 0 indicates success, and non-zero exit code indicates failure. For more information, see HealthCheck in the Create a container section of the Docker Remote API.

Type: Array of strings

Required: Yes

interval

The time period in seconds between each health check execution. You may specify between 5 and 300 seconds. The default value is 30 seconds.

Type: Integer

Required: No

retries

The number of times to retry a failed health check before the container is considered unhealthy. You may specify between 1 and 10 retries. The default value is 3.

Type: Integer

Required: No

startPeriod

The optional grace period within which to provide containers time to bootstrap before failed health checks count towards the maximum number of retries. You may specify between 0 and 300 seconds. The startPeriod is disabled by default.

Note

If a health check succeeds within the startPeriod, then the container is considered healthy and any subsequent failures count toward the maximum number of retries.

Type: Integer

Required: No

timeout

The time period in seconds to wait for a health check to succeed before it is considered a failure. You may specify between 2 and 60 seconds. The default value is 5.

Type: Integer

Required: No

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following: