Create an auto scaling group

An auto scaling group provides the HA capability to Controller instances.

1. In AWS, navigate to Services → EC2 → Compute.
2. In the left panel, under AUTO SCALING, click Auto Scaling Groups.
3. Click Create an Auto Scaling Group. The Choose launch template or configuration page opens.
4. Enter the Name for the configuration.
5. Select the required AMI from Launch template drop-down, and click Next.
   The Create Auto Scaling Group page opens.
6. Define the network and subnet for the group and click Next.

   Option	Definition
   Network	Launch your instance into an Amazon VPC to get complete control over your virtual networking environment.
   Subnet	Subnet where the instances exist

7. (Optional) Enable Load Balancing.
8. (Optional) Configure Health checks and Health Check Grace Period.
9. (Optional) Enable Monitoring to monitor, collect, and analyze metrics about your instances through Amazon CloudWatch.
10. Configure Desired capacity, Minimum capacity, and Maximum capacity of the Auto Scaling group.

    Note

    For external controller, you can have only 1 active instance at a time. Minimum and Max capacity should be configured to 1.
11. Select Target tracking scaling policy and configure Scaling policy name, Metric type, Target value, and Instances need to use a scaling policy that dynamically resizes your Auto Scaling group.
12. Enable Instance scale-in protection. Click Next.
13. Click Add notification to configure notifications to be sent to mail ID during an event of scale out or scale in.

    Option	Definition
    Send a notification to	Email ID to which the notification has to be sent
    Whenever instances	Parameter for which the notification has to be sent. The parameters are as follows: launch terminate fail to launch fail to terminate

14. Click Next to add tags.
15. Click Add tag to add tags. Define tags to the auto scale group which helps identify the group.

    Option	Definition
    Key	Key name for the auto scaling group
    Value	Enter the value for the key.
    Tag New Instances	When this flag is set, the tag will also be applied to any newly launched instances in this Auto Scaling group.

16. Click Review to review the configuration defined for the group.
17. Click Create Auto Scaling Group. The auto scaling group is created and is available in the Auto Scaling Groups page.
18. To delete an auto scaling group, select the auto scaling group, click Actions, and then Delete.