Modifies the status of an Amazon ECS container instance.
ecs_update_container_instances_state(cluster, containerInstances,
status)
The short name or full Amazon Resource Name (ARN) of the cluster that hosts the container instance to update. If you do not specify a cluster, the default cluster is assumed.
[required] A list of container instance IDs or full ARN entries.
[required] The container instance state with which to update the container instance.
svc$update_container_instances_state( cluster = "string", containerInstances = list( "string" ), status = "ACTIVE"|"DRAINING" )
You can change the status of a container instance to DRAINING
to
manually remove an instance from a cluster, for example to perform
system updates, update the Docker daemon, or scale down the cluster
size.
When you set a container instance to DRAINING
, Amazon ECS prevents new
tasks from being scheduled for placement on the container instance and
replacement service tasks are started on other container instances in
the cluster if the resources are available. Service tasks on the
container instance that are in the PENDING
state are stopped
immediately.
Service tasks on the container instance that are in the RUNNING
state
are stopped and replaced according to the service's deployment
configuration parameters, minimumHealthyPercent
and maximumPercent
.
You can change the deployment configuration of your service using
UpdateService.
If minimumHealthyPercent
is below 100%, the scheduler can ignore
desiredCount
temporarily during task replacement. For example,
desiredCount
is four tasks, a minimum of 50% allows the scheduler
to stop two existing tasks before starting two new tasks. If the
minimum is 100%, the service scheduler can't remove existing tasks
until the replacement tasks are considered healthy. 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 task replacement, which enables you
to define the replacement batch size. For example, if desiredCount
is four tasks, a maximum of 200% starts four new tasks before
stopping the four tasks to be drained, provided that the cluster
resources required to do this are available. If the maximum is 100%,
then replacement tasks can't start until the draining tasks have
stopped.
Any PENDING
or RUNNING
tasks that do not belong to a service are not
affected. You must wait for them to finish or stop them manually.
A container instance has completed draining when it has no more
RUNNING
tasks. You can verify this using ListTasks.
When you set a container instance to ACTIVE
, the Amazon ECS scheduler
can begin scheduling tasks on the instance again.