How to Create an Auto Scaling Group with Spot Instances
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How to Create an Auto Scaling Group with Spot Instances
Auto Scaling is a feature of Amazon Web Services (AWS) that allows you to automatically increase or decrease the number of instances in your Amazon Elastic Compute Cloud (EC2) Auto Scaling group based on demand. This can help you save money by using EC2 Spot Instances, which are spare instances that are available at a lower cost than on-demand instances. In this guide, we will go through the steps of creating an Auto Scaling group with Spot Instances on AWS.
Prerequisites
Before you begin, you will need the following:
- An AWS account with access to the EC2 and Auto Scaling services
- A VPC and subnet in which to launch your instances
- An Amazon Machine Image (AMI) to use for your instances
- A security group to control access to your instances
- A launch configuration for your instances
Step 1: Create a Launch Configuration
The first step is to create a launch configuration for your instances. This will define the properties of the instances that will be launched, such as the AMI, instance type, and security group.
- Open the EC2 console in the AWS Management Console.
- In the navigation pane, choose “Launch Configurations” and then choose “Create launch configuration”.
- On the “Choose an Amazon Machine Image” page, choose the AMI that you want to use for your instances.
- On the “Choose an Instance Type” page, choose the instance type that you want to use for your instances.
- On the “Configure Instance Details” page, specify the VPC, subnet, and security group that you want to use for your instances.
- On the “Add storage” page, specify the storage settings for your instances.
- On the “Configure Security Group” page, choose the security group that you want to use for your instances.
- On the “Review” page, review your launch configuration settings, and then choose “Create launch configuration”.
Step 2: Create an Auto Scaling Group
Once you have created a launch configuration, you can create an Auto Scaling group that uses it.
- Open the EC2 Auto Scaling console in the AWS Management Console.
- In the navigation pane, choose “Auto Scaling Groups” and then choose “Create Auto Scaling group”.
- On the “Create Auto Scaling group” page, specify the launch configuration that you created earlier, and then choose “Next”.
- On the “Configure Auto Scaling group details” page, specify the name and other details of your Auto Scaling group, and then choose “Next”.
- On the “Configure scaling policies” page, specify the policies that you want to use to scale your group up or down, and then choose “Next”.
- On the “Configure Notifications” page, specify the notifications that you want to receive when the group scales up or down, and then choose “Next”.
- On the “Configure Tags” page, specify the tags that you want to use to identify your group, and then choose “Next”.
- On the “Review” page, review your settings, and then choose “Create Auto Scaling group”.
Step 3: Enable Spot Instances
- Open the EC2 Auto Scaling console in the AWS Management Console.
- In the navigation pane, choose “Auto Scaling Groups” and select the group you want to enable Spot instances for.
- In the “Capacity” tab, click on the “Edit” button.
- In the “On-Demand Base” field, specify the number of on-demand instances you want to maintain in the group.
- In the “Spot Base” field, specify the number of spot instances you want to maintain in the group.
- In the “Maximum” field, specify the maximum number of instances you want to allow in the group.
- Click on “Save” to apply changes.
With this configuration, your Auto Scaling group will automatically launch Spot Instances when they are available, and fall back to on-demand instances if Spot Instances are not available.
Step 4: Monitor Your Group
You can monitor the status of your Auto Scaling group, as well as the instances that are launched by it, by using the EC2 Auto Scaling console or the AWS Command Line Interface (CLI).
- Open the EC2 Auto Scaling console in the AWS Management Console.
- In the navigation pane, choose “Auto Scaling Groups” and select the group you want to monitor.
- In the “Instances” tab, you can view the status of all instances in the group, as well as their launch configurations and health status.
- In the “CloudWatch Metrics” tab, you can view various metrics for the group, such as the number of instances, the group’s desired, minimum and maximum capacity, and more.
You can also monitor your group by using the AWS CLI.
aws autoscaling describe-auto-scaling-groups --auto-scaling-group-names <your group name>Conclusion
In this guide, I have shown you how to create an Auto Scaling group with Spot Instances on AWS. By using Spot Instances, you can save money on your EC2 costs while maintaining the same level of scalability and availability as on-demand instances. Remember to monitor your group regularly to ensure that it is functioning as expected.
