Example Amazon ECS task placement constraints
The following are task placement constraint examples.
This example uses the memberOf
constraint to place tasks on t2 instances.
It can be specified with the following actions: CreateService, UpdateService, RegisterTaskDefinition,
and RunTask.
"placementConstraints": [ { "expression": "attribute:ecs.instance-type =~ t2.*", "type": "memberOf" } ]
The example uses the memberOf
constraint to place replica tasks on
instances with tasks in the daemon service daemon-service
task group,
respecting any task placement strategies that are also specified. This constraint
ensures that the daemon service tasks get placed on the EC2 instance prior to the
replica service tasks.
Replace daemon-service
with the name of the daemon service.
"placementConstraints": [ { "expression": "task:group == service:
daemon-service
", "type": "memberOf" } ]
The example uses the memberOf
constraint to place tasks on instances with
other tasks in the databases
task group, respecting any task placement
strategies that are also specified. For more information about task groups, see Group related Amazon ECS tasks . It can be specified with the
following actions: CreateService, UpdateService, RegisterTaskDefinition, and RunTask.
"placementConstraints": [ { "expression": "task:group == databases", "type": "memberOf" } ]
The distinctInstance
constraint places each task in the group on a
different instance. It can be specified with the following actions: CreateService, UpdateService, and RunTask
"placementConstraints": [ { "type": "distinctInstance" } ]