如何自动缩放EC2节点

Question

I'm new in AWS, but I want to auto scale my application servers as following requirement:

• I may want to deploy 5 instances on Sunday night
• Then 10 instances on Tuesday
• 15 on Friday
• Then back down to 2 instances on Sat

I've create Auto Scaling Group, but I could not find where I can setup the above scaling configuration.

Answer 1

The Auto Scaling feature of Amazon EC2 can be used to launch or terminate Amazon EC2 instances to meet desired capacity.

In its simplest form, Auto Scaling maintains a given number of instances (eg 5 instances). If an instance fails, an the Availability Zone fails, then Auto Scaling will automatically launch replacement instances to maintain the given count.

The Desired Capacity can be modified via the execution of a Scaling Policy or a Schedule .

Scaling Policies tell Auto Scaling to modify the number of instances. For example, +1 or +100% . These scaling policies are typically triggered by an Amazon CloudWatch Alarm based on metrics such as CPU Utilization or the number of jobs waiting in a queue.

However, your use case involves Schedule Scaling of instances. This is where you can specify a schedule for modifying:

• The Desired Capacity (the number of instances)
• The Minimum number of instances
• The Maximum number of instances (both used to set limits on the number of instances in the Auto Scaling group)

Your use-case would involve creating four scheduled actions .

See: Scheduled Scaling documentation