update-service — AWS CLI 2.1.21 Command Reference

Description

Warning

Updating the task placement strategies and constraints on an Amazon ECS service remains in preview and is a Beta Service as defined by and subject to the Beta Service Participation Service Terms located at (“Beta Terms”). These Beta Terms apply to your participation in this preview.

Modifies the parameters of a service.

For services using the rolling update (ECS ) deployment controller, the desired count, deployment configuration, network configuration, task placement constraints and strategies, or task definition used can be updated.

For services using the blue/green (CODE_DEPLOY ) deployment controller, only the desired count, deployment configuration, task placement constraints and strategies, and health check grace period can be updated using this API. If the network configuration, platform version, or task definition need to be updated, a new AWS CodeDeploy deployment should be created. For more information, see CreateDeployment in the AWS CodeDeploy API Reference .

For services using an external deployment controller, you can update only the desired count, task placement constraints and strategies, and health check grace period using this API. If the launch type, load balancer, network configuration, platform version, or task definition need to be updated, you should create a new task set. For more information, see CreateTaskSet .

You can add to or subtract from the number of instantiations of a task definition in a service by specifying the cluster that the service is running in and a new desiredCount parameter.

If you have updated the Docker image of your application, you can create a new task definition with that image and deploy it to your service. The service scheduler uses the minimum healthy percent and maximum percent parameters (in the service’s deployment configuration) to determine the deployment strategy.

Note

If your updated Docker image uses the same tag as what is in the existing task definition for your service (for example, my_image:latest ), you do not need to create a new revision of your task definition. You can update the service using the forceNewDeployment option. The new tasks launched by the deployment pull the current image/tag combination from your repository when they start.

You can also update the deployment configuration of a service. When a deployment is triggered by updating the task definition of a service, the service scheduler uses the deployment configuration parameters, minimumHealthyPercent and maximumPercent , to determine the deployment strategy.

• If minimumHealthyPercent is below 100%, the scheduler can ignore desiredCount temporarily during a deployment. For example, if desiredCount is four tasks, a minimum of 50% allows the scheduler to stop two existing tasks before starting two new tasks. Tasks for services that do not use a load balancer are considered healthy if they are in the RUNNING state. Tasks for services that use a load balancer are considered healthy if they are in the RUNNING state and the container instance they are hosted on is reported as healthy by the load balancer.

• The maximumPercent parameter represents an upper limit on the number of running tasks during a deployment, which enables you to define the deployment batch size. For example, if desiredCount is four tasks, a maximum of 200% starts four new tasks before stopping the four older tasks (provided that the cluster resources required to do this are available).

When UpdateService stops a task during a deployment, the equivalent of docker stop is issued to the containers running in the task. This results in a SIGTERM and a 30-second timeout, after which SIGKILL is sent and the containers are forcibly stopped. If the container handles the SIGTERM gracefully and exits within 30 seconds from receiving it, no SIGKILL is sent.

When the service scheduler launches new tasks, it determines task placement in your cluster with the following logic:

• Determine which of the container instances in your cluster can support your service’s task definition (for example, they have the required CPU, memory, ports, and container instance attributes).

• By default, the service scheduler attempts to balance tasks across Availability Zones in this manner (although you can choose a different placement strategy):

  • Sort the valid container instances by the fewest number of running tasks for this service in the same Availability Zone as the instance. For example, if zone A has one running service task and zones B and C each have zero, valid container instances in either zone B or C are considered optimal for placement.

  • Place the new service task on a valid container instance in an optimal Availability Zone (based on the previous steps), favoring container instances with the fewest number of running tasks for this service.

When the service scheduler stops running tasks, it attempts to maintain balance across the Availability Zones in your cluster using the following logic:

• Sort the container instances by the largest number of running tasks for this service in the same Availability Zone as the instance. For example, if zone A has one running service task and zones B and C each have two, container instances in either zone B or C are considered optimal for termination.

• Stop the task on a container instance in an optimal Availability Zone (based on the previous steps), favoring container instances with the largest number of running tasks for this service.

See also: AWS API Documentation

See ‘aws help’ for descriptions of global parameters.

Options

--cluster (string)

The short name or full Amazon Resource Name (ARN) of the cluster that your service is running on. If you do not specify a cluster, the default cluster is assumed.

--service (string)

The name of the service to update.

--desired-count (integer)

The number of instantiations of the task to place and keep running in your service.

--task-definition (string)

The family and revision (family:revision ) or full ARN of the task definition to run in your service. If a revision is not specified, the latest ACTIVE revision is used. If you modify the task definition with UpdateService , Amazon ECS spawns a task with the new version of the task definition and then stops an old task after the new version is running.

--capacity-provider-strategy (list)

The capacity provider strategy to update the service to use.

If the service is using the default capacity provider strategy for the cluster, the service can be updated to use one or more capacity providers as opposed to the default capacity provider strategy. However, when a service is using a capacity provider strategy that is not the default capacity provider strategy, the service cannot be updated to use the cluster’s default capacity provider strategy.

A capacity provider strategy consists of one or more capacity providers along with the base and weight to assign to them. A capacity provider must be associated with the cluster to be used in a capacity provider strategy. The PutClusterCapacityProviders API is used to associate a capacity provider with a cluster. Only capacity providers with an ACTIVE or UPDATING status can be used.

If specifying a capacity provider that uses an Auto Scaling group, the capacity provider must already be created. New capacity providers can be created with the CreateCapacityProvider API operation.

To use a AWS Fargate capacity provider, specify either the FARGATE or FARGATE_SPOT capacity providers. The AWS Fargate capacity providers are available to all accounts and only need to be associated with a cluster to be used.

The PutClusterCapacityProviders API operation is used to update the list of available capacity providers for a cluster after the cluster is created.

(structure)

The details of a capacity provider strategy.

capacityProvider -> (string)

The short name of the capacity provider.

weight -> (integer)

The weight value designates the relative percentage of the total number of tasks launched that should use the specified capacity provider.

For example, if you have a strategy that contains two capacity providers and both have a weight of 1 , then when the base is satisfied, the tasks will be split evenly across the two capacity providers. Using that same logic, if you specify a weight of 1 for capacityProviderA and a weight of 4 for capacityProviderB , then for every one task that is run using capacityProviderA , four tasks would use capacityProviderB .

base -> (integer)

The base value designates how many tasks, at a minimum, to run on the specified capacity provider. Only one capacity provider in a capacity provider strategy can have a base defined.

Shorthand Syntax:

capacityProvider=string,weight=integer,base=integer ...

JSON Syntax:

[ { "capacityProvider": "string", "weight": integer, "base": integer } ...]

--deployment-configuration (structure)

Optional deployment parameters that control how many tasks run during the deployment and the ordering of stopping and starting tasks.

deploymentCircuitBreaker -> (structure)

Note

The deployment circuit breaker can only be used for services using the rolling update (ECS ) deployment type.

The deployment circuit breaker determines whether a service deployment will fail if the service can’t reach a steady state. If deployment circuit breaker is enabled, a service deployment will transition to a failed state and stop launching new tasks. If rollback is enabled, when a service deployment fails, the service is rolled back to the last deployment that completed successfully.

enable -> (boolean)

Whether to enable the deployment circuit breaker logic for the service.

rollback -> (boolean)

Whether to enable Amazon ECS to roll back the service if a service deployment fails. If rollback is enabled, when a service deployment fails, the service is rolled back to the last deployment that completed successfully.

maximumPercent -> (integer)

If a service is using the rolling update (ECS ) deployment type, the maximum percent parameter represents an upper limit on the number of tasks in a service that are allowed in the RUNNING or PENDING state during a deployment, as a percentage of the desired number of tasks (rounded down to the nearest integer), and while any container instances are in the DRAINING state if the service contains tasks using the EC2 launch type. This parameter enables you to define the deployment batch size. For example, if your service has a desired number of four tasks and a maximum percent value of 200%, the scheduler may start four new tasks before stopping the four older tasks (provided that the cluster resources required to do this are available). The default value for maximum percent is 200%.

If a service is using the blue/green (CODE_DEPLOY ) or EXTERNAL deployment types and tasks that use the EC2 launch type, the maximum percent value is set to the default value and is used to define the upper limit on the number of the tasks in the service that remain in the RUNNING state while the container instances are in the DRAINING state. If the tasks in the service use the Fargate launch type, the maximum percent value is not used, although it is returned when describing your service.

minimumHealthyPercent -> (integer)

If a service is using the rolling update (ECS ) deployment type, the minimum healthy percent represents a lower limit on the number of tasks in a service that must remain in the RUNNING state during a deployment, as a percentage of the desired number of tasks (rounded up to the nearest integer), and while any container instances are in the DRAINING state if the service contains tasks using the EC2 launch type. This parameter enables you to deploy without using additional cluster capacity. For example, if your service has a desired number of four tasks and a minimum healthy percent of 50%, the scheduler may stop two existing tasks to free up cluster capacity before starting two new tasks. Tasks for services that do not use a load balancer are considered healthy if they are in the RUNNING state; tasks for services that do use a load balancer are considered healthy if they are in the RUNNING state and they are reported as healthy by the load balancer. The default value for minimum healthy percent is 100%.

If a service is using the blue/green (CODE_DEPLOY ) or EXTERNAL deployment types and tasks that use the EC2 launch type, the minimum healthy percent value is set to the default value and is used to define the lower limit on the number of the tasks in the service that remain in the RUNNING state while the container instances are in the DRAINING state. If the tasks in the service use the Fargate launch type, the minimum healthy percent value is not used, although it is returned when describing your service.

Shorthand Syntax:

deploymentCircuitBreaker={enable=boolean,rollback=boolean},maximumPercent=integer,minimumHealthyPercent=integer

JSON Syntax:

{ "deploymentCircuitBreaker": { "enable": true|false, "rollback": true|false }, "maximumPercent": integer, "minimumHealthyPercent": integer}

--network-configuration (structure)

An object representing the network configuration for a task or service.

awsvpcConfiguration -> (structure)

The VPC subnets and security groups associated with a task.

Note

All specified subnets and security groups must be from the same VPC.

subnets -> (list)

The IDs of the subnets associated with the task or service. There is a limit of 16 subnets that can be specified per AwsVpcConfiguration .

Note

All specified subnets must be from the same VPC.

(string)

securityGroups -> (list)

The IDs of the security groups associated with the task or service. If you do not specify a security group, the default security group for the VPC is used. There is a limit of 5 security groups that can be specified per AwsVpcConfiguration .

Note

All specified security groups must be from the same VPC.

(string)

assignPublicIp -> (string)

Whether the task’s elastic network interface receives a public IP address. The default value is DISABLED .

Shorthand Syntax:

awsvpcConfiguration={subnets=[string,string],securityGroups=[string,string],assignPublicIp=string}

JSON Syntax:

{ "awsvpcConfiguration": { "subnets": ["string", ...], "securityGroups": ["string", ...], "assignPublicIp": "ENABLED"|"DISABLED" }}

--placement-constraints (list)

An array of task placement constraint objects to update the service to use. If no value is specified, the existing placement constraints for the service will remain unchanged. If this value is specified, it will override any existing placement constraints defined for the service. To remove all existing placement constraints, specify an empty array.

You can specify a maximum of 10 constraints per task (this limit includes constraints in the task definition and those specified at runtime).

(structure)

An object representing a constraint on task placement. For more information, see Task Placement Constraints in the Amazon Elastic Container Service Developer Guide .

Note

If you are using the Fargate launch type, task placement constraints are not supported.

type -> (string)

The type of constraint. Use distinctInstance to ensure that each task in a particular group is running on a different container instance. Use memberOf to restrict the selection to a group of valid candidates.

expression -> (string)

A cluster query language expression to apply to the constraint. You cannot specify an expression if the constraint type is distinctInstance . For more information, see Cluster Query Language in the Amazon Elastic Container Service Developer Guide .

Shorthand Syntax:

type=string,expression=string ...

JSON Syntax:

[ { "type": "distinctInstance"|"memberOf", "expression": "string" } ...]

--placement-strategy (list)

The task placement strategy objects to update the service to use. If no value is specified, the existing placement strategy for the service will remain unchanged. If this value is specified, it will override the existing placement strategy defined for the service. To remove an existing placement strategy, specify an empty object.

You can specify a maximum of five strategy rules per service.

(structure)

The task placement strategy for a task or service. For more information, see Task Placement Strategies in the Amazon Elastic Container Service Developer Guide .

type -> (string)

The type of placement strategy. The random placement strategy randomly places tasks on available candidates. The spread placement strategy spreads placement across available candidates evenly based on the field parameter. The binpack strategy places tasks on available candidates that have the least available amount of the resource that is specified with the field parameter. For example, if you binpack on memory, a task is placed on the instance with the least amount of remaining memory (but still enough to run the task).

field -> (string)

The field to apply the placement strategy against. For the spread placement strategy, valid values are instanceId (or host , which has the same effect), or any platform or custom attribute that is applied to a container instance, such as attribute:ecs.availability-zone . For the binpack placement strategy, valid values are cpu and memory . For the random placement strategy, this field is not used.

Shorthand Syntax:

type=string,field=string ...

JSON Syntax:

[ { "type": "random"|"spread"|"binpack", "field": "string" } ...]

--platform-version (string)

The platform version on which your tasks in the service are running. A platform version is only specified for tasks using the Fargate launch type. If a platform version is not specified, the LATEST platform version is used by default. For more information, see AWS Fargate Platform Versions in the Amazon Elastic Container Service Developer Guide .

--force-new-deployment | --no-force-new-deployment (boolean)

Whether to force a new deployment of the service. Deployments are not forced by default. You can use this option to trigger a new deployment with no service definition changes. For example, you can update a service’s tasks to use a newer Docker image with the same image/tag combination (my_image:latest ) or to roll Fargate tasks onto a newer platform version.

--health-check-grace-period-seconds (integer)

The period of time, in seconds, that the Amazon ECS service scheduler should ignore unhealthy Elastic Load Balancing target health checks after a task has first started. This is only valid if your service is configured to use a load balancer. If your service’s tasks take a while to start and respond to Elastic Load Balancing health checks, you can specify a health check grace period of up to 2,147,483,647 seconds. During that time, the Amazon ECS service scheduler ignores the Elastic Load Balancing health check status. This grace period can prevent the ECS service scheduler from marking tasks as unhealthy and stopping them before they have time to come up.

--cli-input-json | --cli-input-yaml (string) Reads arguments from the JSON string provided. The JSON string follows the format provided by --generate-cli-skeleton. If other arguments are provided on the command line, those values will override the JSON-provided values. It is not possible to pass arbitrary binary values using a JSON-provided value as the string will be taken literally. This may not be specified along with --cli-input-yaml.

--generate-cli-skeleton (string) Prints a JSON skeleton to standard output without sending an API request. If provided with no value or the value input, prints a sample input JSON that can be used as an argument for --cli-input-json. Similarly, if provided yaml-input it will print a sample input YAML that can be used with --cli-input-yaml. If provided with the value output, it validates the command inputs and returns a sample output JSON for that command.

See ‘aws help’ for descriptions of global parameters.

Examples

Example 1: To change the task definition used in a service

The following update-service example updates the my-http-service service to use the amazon-ecs-sample task definition.

aws ecs update-service --service my-http-service --task-definition amazon-ecs-sample

Example 2: To change the number of tasks in a service

The following update-service example updates the desired task count of the service my-http-service to 3.

aws ecs update-service --service my-http-service --desired-count 3

For more information, see Updating a Service in the Amazon ECS Developer Guide.