Tutorial: Using cluster auto scaling with the AWS Management Console

Amazon ECS cluster auto scaling can be set up and configured using the AWS Management Console, AWS CLI, or Amazon ECS API.

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.

For an AWS CLI tutorial, see Tutorial: Using cluster auto scaling with the AWS CLI.

Prerequisites

This tutorial assumes that the following prerequisites have been completed:

• The steps in Setting up with Amazon ECS have been completed.

• Your AWS user has the required permissions specified in the Amazon ECS First Run Wizard Permissions 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 Service-Linked Role 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 Tutorial: Creating a VPC with Public and Private Subnets for Your Clusters.

Step 1: Create an Amazon ECS cluster

Use the following steps to create an Amazon ECS cluster. This tutorial uses an empty cluster so that we can manually create the Auto Scaling resources. When you use the AWS Management Console to create a non-empty cluster, Amazon ECS creates an AWS CloudFormation stack along with Auto Scaling resources. We want to avoid creating this AWS CloudFormation stack when using the cluster auto scaling feature.

To create an empty cluster

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

2. On the navigation bar at the top of the screen, select the US West (Oregon) Region.

3. In the navigation pane, choose Clusters.

4. On the Clusters page, choose Create Cluster.

5. For Select cluster compatibility, choose EC2 Linux + Networking and then choose Next step.

6. For Cluster name, enter ConsoleTutorial-cluster for the cluster name.

7. Select Create an empty cluster and then choose Create.

Step 2: Create the Auto Scaling Resources

Note

Use the old version of the EC2 Console for the auto scaling group sections of this tutorial.

Use the following steps to create an Auto Scaling launch configuration and Auto Scaling group.

To create an Auto Scaling launch configuration

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 US West (Oregon) Region.

3. On the navigation pane, under Auto Scaling, choose Launch Configurations.

4. On the next page, choose Create launch configuration.

5. On the Choose AMI page, search for and choose the latest Amazon ECS-optimized Amazon Linux 2 AMI in the us-west-2 Region. The AMI ID can be retrieved using the following link: View AMI ID.

6. On the Choose Instance Type page, select t2.micro, then choose Next: Configure details.

7. On the Configure details page, do the following:

   1. For Name, enter ConsoleTutorial-ASGlaunchconfig for the launch configuration name.

   2. For IAM role, select your container instance IAM role. For more information, see Amazon ECS Container Instance IAM Role.

   3. Expand the Advanced Details section to specify user data for your Amazon ECS container instances.

      Paste the following script into the User data field. The ConsoleTutorial-cluster cluster was created in the first step.

      #!/bin/bash
      echo ECS_CLUSTER=ConsoleTutorial-cluster >> /etc/ecs/ecs.config

   4. Choose Skip to review.

8. Choose Create launch configuration.

Next, create an Auto Scaling group using that launch configuration.

To create an Auto Scaling group

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 US West (Oregon) Region.

3. On the navigation pane, under Auto Scaling, choose Launch Configurations.

4. On the next page, select the launch configuration we created in step 1 and choose Create Auto Scaling group.

5. On the Configure Auto Scaling group details page, do the following:

   1. For Group name, enter ConsoleTutorial-ASG for the Auto Scaling group name.

   2. For Group size, enter 0. The tutorial uses Amazon ECS managed scaling so there is no need to have the Auto Scaling group launch any initial instances.

   3. For Network, choose a VPC for your Auto Scaling group.

   4. For Subnet, choose a subnet in your VPC.

   5. Expand the Advanced Details section. For Instance Protection, choose Protect From Scale In. This enables you to use managed termination protection for the instances in the Auto Scaling group, which prevents your container instances that contain tasks from being terminated during scale-in actions.

6. Choose Next: Configure scaling policies.

7. On the Configure scaling policies page, select Keep this group at its initial size. The tutorial uses Amazon ECS managed scaling so there is no need to create a scaling policy.

8. Choose Review, Create Auto Scaling group.

9. Repeat steps 3 to 8 to create a second Auto Scaling group but for Group name use ConsoleTutorial-ASG-burst.

10. Use the following steps to edit the max capacity value for each of your Auto Scaling groups.

    1. Choose View your Auto Scaling groups.

    2. Select your ConsoleTutorial-ASG scaling group. From the Details tab, choose Edit.

    3. For Max, enter 100, then choose Save.

11. Repeat step 10 for your ConsoleTutorial-ASG-burst scaling group.

Step 3: Create a Capacity Provider

Use the following steps to create an Amazon ECS capacity provider. See Amazon ECS capacity providers for more information.

To create a capacity provider

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

2. On the navigation bar at the top of the screen, select the US West (Oregon) Region.

3. In the navigation pane, choose Clusters.

4. On the Clusters page, select your ConsoleTutorial-cluster cluster.

5. On the Capacity Providers tab, choose Create.

6. On the Create Capacity Providers window, do the following.

   1. For Capacity provider name, enter ConsoleTutorial-capacityprovider for the name.

   2. For Auto Scaling group, select the ConsoleTutorial-ASG Auto Scaling group you created.

   3. For Managed scaling, choose Enabled. This enables Amazon ECS to manage the scale-in and scale-out actions for the capacity provider.

   4. For Target capacity %, enter 100.

   5. For Managed termination protection, choose Enabled. This prevents your container instances that contain tasks and that are in the Auto Scaling group from being terminated during a scale-in action.

   6. Choose Create.

      Important

      If you receive an error during this step, try logging out and back in to the console. If the error does not clear, we recommend using the AWS CLI tutorial. For more information, see Tutorial: Using cluster auto scaling with the AWS CLI.

   7. Choose View in cluster to see your new capacity provider.

   8. Repeat steps 4 to 6, creating a second capacity provider with name ConsoleTutorial-capacityprovider-burst with your ConsoleTutorial-ASG-burst Auto Scaling group.

Step 4: Set a Default Capacity Provider Strategy for the Cluster

When running a task or creating a service, the Amazon ECS console uses the default capacity provider strategy for the cluster. The default capacity provider strategy can be defined by updating the cluster.

To define a default capacity provider strategy

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

2. On the navigation bar at the top of the screen, select the US West (Oregon) Region.

3. In the navigation pane, choose Clusters.

4. On the Clusters page, select your ConsoleTutorial-cluster cluster.

5. On the Cluster : ConsoleTutorial-cluster page, choose Update Cluster.

6. For Default capacity provider strategy choose, Add provider.

7. Select your ConsoleTutorial-capacityprovider capacity provider.

8. Choose Add provider, select your ConsoleTutorial-capacityprovider-burst capacity provider.

9. For Provider 1, leave the Base value at 0 and leave the Weight value at 1.

10. Choose Update. This will add the capacity providers to the default capacity provider strategy for the cluster.

11. Choose View cluster.

Step 5: 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.

To register a task definition

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

2. On the navigation bar at the top of the screen, select the US West (Oregon) Region.

3. In the navigation pane, choose Task Definitions, Create new Task Definition.

4. On the Create new Task Definition page, select EC2, Next step.

5. Choose Configure via JSON and copy and paste the following contents and then choose Save, Create.

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

Step 6: 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.

To run a task

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

2. On the navigation bar at the top of the screen, select the US West (Oregon) Region.

3. In the navigation pane, choose Task Definitions.

4. Select your ConsoleTutorial-taskdef task definition.

5. From the Actions menu, choose Run Task.

6. Use the following steps to complete the run task workflow.

   1. For Capacity provider strategy, the default capacity provider strategy for the cluster must be selected.

   2. For Cluster, select your ConsoleTutorial-cluster cluster.

   3. For Number of tasks, enter 5.

   4. For Placement Templates, choose BinPack.

   5. Choose Run Task.

Step 7: Verify

At this point in the tutorial, you should have two Auto Scaling groups with one capacity provider for each of them. The capacity providers have Amazon ECS managed scaling enabled. A cluster was created and five tasks are running.

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 US West (Oregon) Region.

3. On the navigation pane, choose Metrics.

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

5. Choose CapacityProviderName, ClusterName.

6. Choose the metric that corresponds to the ConsoleTutorial-capacityprovider capacity provider.

7. On 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.

   

8. Steps 5 to 6 can be repeated for your ConsoleTutorial-capacityprovider-burst metric.

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 US West (Oregon) Region.

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

4. For each of your Auto Scaling groups, view the values in the Instances and Desired columns to confirm your group scaled out to two instances for each group.

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 Auto Scaling group scaled out

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

2. On the navigation bar at the top of the screen, select the US West (Oregon) Region.

3. In the navigation pane, choose Clusters.

4. On the Clusters page, select your ConsoleTutorial-cluster cluster.

5. On the ECS Instances tab, confirm you see four instances registered, which matches your Auto Scaling group values.

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

Step 8: 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 Amazon ECS console at https://console.aws.amazon.com/ecs/.

2. On the navigation bar at the top of the screen, select the US West (Oregon) Region.

3. In the navigation pane, choose Clusters.

4. On the Clusters page, select your ConsoleTutorial-cluster cluster.

5. From the Tasks tab, choose Stop All. Enter the verification and choose Stop all again.

6. 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 US West (Oregon) Region.

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

   4. Select your ConsoleTutorial-ASG Auto Scaling group, then from the Actions menu choose Delete.

   5. Select your ConsoleTutorial-ASG-burst Auto Scaling group, then from the Actions menu choose Delete.

7. Open the Amazon ECS console at https://console.aws.amazon.com/ecs/.

8. On the navigation bar at the top of the screen, select the US West (Oregon) Region.

9. In the navigation pane, choose Clusters.

10. On the Clusters page, select your ConsoleTutorial-cluster cluster.

11. Choose Delete Cluster, enter the confirmation phrase, and choose Delete.