Using cluster auto scaling with the AWS Management Console and the Amazon ECS console

This tutorial walks you through creating the resources for cluster auto scaling using the AWS Management Console. Where resources require a name, we will use the prefix ConsoleTutorial to ensure they all have unique names and to make them easy to locate.

Prerequisites

This tutorial assumes that the following prerequisites have been completed:

• The steps in Set up to use Amazon ECS have been completed.

• Your AWS user has the required permissions specified in the AmazonECS_FullAccess IAM policy example.

• The Amazon ECS container instance IAM role is created. For more information, see Amazon ECS container instance IAM role.

• The Amazon ECS service-linked IAM role is created. For more information, see Using service-linked roles for Amazon ECS.

• The Auto Scaling service-linked IAM role is created. For more information, see Service-Linked Roles for Amazon EC2 Auto Scaling in the Amazon EC2 Auto Scaling User Guide.

• You have a VPC and security group created to use. For more information, see Create a virtual private cloud.

Step 1: Create an Amazon ECS cluster

Use the following steps to create an Amazon ECS cluster.

Amazon ECS creates an Amazon EC2 Auto Scaling launch template and Auto Scaling group on your behalf as part of the AWS CloudFormation stack.

1. Open the console at https://console.aws.amazon.com/ecs/v2.

2. In the navigation pane, choose Clusters, and then choose Create cluster.

3. Under Cluster configuration, for Cluster name, enter ConsoleTutorial-cluster.

4. Under Infrastructure, clear AWS Fargate (serverless), and then select Amazon EC2 instances. Next, configure the Auto Scaling group which acts as the capacity provider.

   1. Under Auto Scaling group (ASG) . Select Create new ASG, and then provide the following details about the group:

      • For Operating system/Architecture, choose Amazon Linux 2.

      • For EC2 instance type, choose t3.nano.

      • For Capacity, enter the minimum number and the maximum number of instances to launch in the Auto Scaling group.

5. (Optional) To manage the cluster tags, expand Tags, and then perform one of the following operations:

   [Add a tag] Choose Add tag and do the following:

   • For Key, enter the key name.

   • For Value, enter the key value.

   [Remove a tag] Choose Remove to the right of the tag’s Key and Value.

6. Choose Create.

Step 2: Register a task definition

Before you can run a task on your cluster, you must register a task definition. Task definitions are lists of containers grouped together. The following example is a simple task definition that uses an amazonlinux image from Docker Hub and simply sleeps. For more information about the available task definition parameters, see Amazon ECS task definitions.

1. Open the console at https://console.aws.amazon.com/ecs/v2.

2. In the navigation pane, choose Task definitions.

3. Choose Create new task definition, Create new task definition with JSON.

4. In the JSON editor box, paste the following contents.

   {
       "family": "ConsoleTutorial-taskdef",
       "containerDefinitions": [
           {
               "name": "sleep",
               "image": "amazonlinux:2",
               "memory": 20,
               "essential": true,
               "command": [
                   "sh",
                   "-c",
                   "sleep infinity"
               ]
           }
       ],
       "requiresCompatibilities": [
           "EC2"
       ]
   }

5. Choose Create.

Step 3: Run a task

After you have registered a task definition for your account, you can run a task in the cluster. For this tutorial, you run five instances of the ConsoleTutorial-taskdef task definition in your ConsoleTutorial-cluster cluster.

1. Open the console at https://console.aws.amazon.com/ecs/v2.

2. On the Clusters page, choose ConsoleTutorial-cluster.

3. Under Tasks, choose Run new task.

4. In the Environment section, under Compute options, choose Capacity provider strategy.

5. Under Deployment configuration, for Application type, choose Task.

6. Choose ConsoleTutorial-taskdef from the Family dropdown list.

7. Under Desired tasks, enter 5.

8. Choose Create.

Step 4: Verify

At this point in the tutorial, you should have a cluster with five tasks running and an Auto Scaling group with a capacity provider. The capacity provider has Amazon ECS managed scaling enabled.

We can verify that everything is working properly by viewing the CloudWatch metrics, the Auto Scaling group settings, and finally the Amazon ECS cluster task count.

To view the CloudWatch metrics for your cluster

1. Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

2. On the navigation bar at the top of the screen, select the Region.

3. On the navigation pane, under Metrics, choose All metrics.

4. On the All metrics page, under the Browse tab, choose AWS/ECS/ManagedScaling.

5. Choose CapacityProviderName, ClusterName.

6. Select the check box that corresponds to the ConsoleTutorial-cluster ClusterName.

7. Under the Graphed metrics tab, change Period to 30 seconds and Statistic to Maximum.

   The value displayed in the graph shows the target capacity value for the capacity provider. It should begin at 100, which was the target capacity percent we set. You should see it scale up to 200, which will trigger an alarm for the target tracking scaling policy. The alarm will then trigger the Auto Scaling group to scale out.

Use the following steps to view your Auto Scaling group details to confirm that the scale-out action occurred.

To verify the Auto Scaling group scaled out

1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2. On the navigation bar at the top of the screen, select the Region.

3. On the navigation pane, under Auto Scaling, choose Auto Scaling Groups.

4. Choose the ConsoleTutorial-cluster Auto Scaling group created in this tutorial. View the value under Desired capacity and view the instances under the Instance management tab to confirm your group scaled out to two instances.

Use the following steps to view your Amazon ECS cluster to confirm that the Amazon EC2 instances were registered with the cluster and your tasks transitioned to a RUNNING status.

To verify the instances in the Auto Scaling group

1. Open the console at https://console.aws.amazon.com/ecs/v2.

2. In the navigation pane, choose Clusters.

3. On the Clusters page, choose the ConsoleTutorial-cluster cluster.

4. On the Tasks tab, confirm you see five tasks in the RUNNING status.

Step 5: Clean up

When you have finished this tutorial, clean up the resources associated with it to avoid incurring charges for resources that you aren't using. Deleting capacity providers and task definitions are not supported, but there is no cost associated with these resources.

To clean up the tutorial resources

1. Open the console at https://console.aws.amazon.com/ecs/v2.

2. In the navigation pane, choose Clusters.

3. On the Clusters page, choose ConsoleTutorial-cluster.

4. On the ConsoleTutorial-cluster page, choose the Tasks tab, and then choose Stop, Stop all.

5. In the navigation pane, choose Clusters.

6. On the Clusters page, choose ConsoleTutorial-cluster.

7. In the upper-right of the page, choose Delete cluster.

8. In the confirmation box, enter delete ConsoleTutorial-cluster and choose Delete.

9. Delete the Auto Scaling groups using the following steps.

   1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

   2. On the navigation bar at the top of the screen, select the Region.

   3. On the navigation pane, under Auto Scaling, choose Auto Scaling Groups.

   4. Select the ConsoleTutorial-cluster Auto Scaling group, then choose Actions.

   5. From the Actions menu, choose Delete. Enter delete in the confirmation box and then choose Delete.