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
You can use UpdateService to modify your task definition and deploy a new version of your service.
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,
to determine the deployment strategy.
minimumHealthyPercent is below 100%, the scheduler can ignore
desiredCount temporarily during a deployment. For example, if your
service has a
desiredCount of four tasks, a
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 do use
a load balancer are considered healthy if they are in the
and the container instance it is hosted on is reported as healthy by the load balancer.
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 your service has a
desiredCount of four tasks,
maximumPercent value of 200% starts four new tasks before stopping
the four older tasks (provided that the cluster resources required to do this are
When UpdateService stops a task during a deployment, the equivalent of
docker stopis issued to the containers running in the task. This results in a
SIGTERMand a 30-second timeout, after which
SIGKILLis sent and the containers are forcibly stopped. If the container handles the
SIGTERMgracefully and exits within 30 seconds from receiving it, no
When the service scheduler launches new tasks, it attempts to balance them across the Availability Zones 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).
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.
Version: (assembly version)
public class UpdateServiceRequest : AmazonECSRequest IRequestEvents
The UpdateServiceRequest type exposes the following members
Gets and sets the property Cluster.
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.
Gets and sets the property DeploymentConfiguration.
Optional deployment parameters that control how many tasks run during the deployment and the ordering of stopping and starting tasks.
Gets and sets the property DesiredCount.
The number of instantiations of the task to place and keep running in your service.
Gets and sets the property Service.
The name of the service to update.
Gets and sets the property TaskDefinition.
Supported in: 4.5, 4.0, 3.5
.NET for Windows Store apps:
Supported in: Windows 8