**To update the primary task set for a service** The following ``update-service-primary-task-set`` example updates the primary task set for the specified service. :: aws ecs update-service-primary-task-set \ --cluster MyCluster \ --service MyService \ --primary-task-set arn:aws:ecs:us-west-2:123456789012:task-set/MyCluster/MyService/ecs-svc/1234567890123456789 Output:: { "taskSet": { "id": "ecs-svc/1234567890123456789", "taskSetArn": "arn:aws:ecs:us-west-2:123456789012:task-set/MyCluster/MyService/ecs-svc/1234567890123456789", "status": "PRIMARY", "taskDefinition": "arn:aws:ecs:us-west-2:123456789012:task-definition/sample-fargate:2", "computedDesiredCount": 1, "pendingCount": 0, "runningCount": 0, "createdAt": 1557128360.711, "updatedAt": 1557129412.653, "launchType": "EC2", "networkConfiguration": { "awsvpcConfiguration": { "subnets": [ "subnet-12344321" ], "securityGroups": [ "sg-12344312" ], "assignPublicIp": "DISABLED" } }, "loadBalancers": [], "serviceRegistries": [], "scale": { "value": 50.0, "unit": "PERCENT" }, "stabilityStatus": "STABILIZING", "stabilityStatusAt": 1557129279.914 } }