Alarm actions (SNS, Auto Scaling) in AWS - Mini Project: Build & Apply

Alarm actions (SNS, Auto Scaling)

📖 Scenario: You are managing a cloud environment where you want to monitor the CPU usage of your servers. When the CPU usage goes above a certain limit, you want to send a notification and also automatically add more servers to handle the load.

🎯 Goal: Create a CloudWatch alarm that monitors CPU usage. Configure it to send a notification to an SNS topic and trigger an Auto Scaling policy to add more servers when the alarm is triggered.

📋 What You'll Learn

Create a CloudWatch alarm named HighCPUAlarm that monitors CPUUtilization metric.

Create an SNS topic named HighCPUNotification.

Create an Auto Scaling policy named ScaleOutPolicy.

Configure the alarm to send notifications to the SNS topic and trigger the Auto Scaling policy.

💡 Why This Matters

🌍 Real World

This project simulates a common cloud scenario where automatic scaling and alerting help maintain application performance and availability.

💼 Career

Understanding how to configure alarms, notifications, and auto scaling is essential for cloud engineers and DevOps professionals to manage cloud infrastructure efficiently.

1

Create the SNS topic

Create an SNS topic named HighCPUNotification using AWS CloudFormation syntax.

AWS

# Your code here to create SNS topic named HighCPUNotification

Need a hint?

Use AWS::SNS::Topic resource type and set TopicName to HighCPUNotification.

2

Create the Auto Scaling policy

Add an Auto Scaling policy named ScaleOutPolicy that increases the desired capacity by 1 when triggered.

AWS

Resources:
  HighCPUNotification:
    Type: AWS::SNS::Topic
    Properties:
      TopicName: HighCPUNotification

# Your code here to create Auto Scaling policy named ScaleOutPolicy

Need a hint?

Use AWS::AutoScaling::ScalingPolicy with ScalingAdjustment set to 1.

3

Create the CloudWatch alarm

Create a CloudWatch alarm named HighCPUAlarm that monitors the CPUUtilization metric of the Auto Scaling group. Set the threshold to 70 and evaluation periods to 2.

AWS

Resources:
  HighCPUNotification:
    Type: AWS::SNS::Topic
    Properties:
      TopicName: HighCPUNotification

  ScaleOutPolicy:
    Type: AWS::AutoScaling::ScalingPolicy
    Properties:
      AutoScalingGroupName: !Ref AutoScalingGroup
      PolicyType: SimpleScaling
      AdjustmentType: ChangeInCapacity
      ScalingAdjustment: 1
      Cooldown: 300

# Your code here to create CloudWatch alarm named HighCPUAlarm

Need a hint?

Use AWS::CloudWatch::Alarm with AlarmActions referencing the SNS topic and Auto Scaling policy.

4

Complete the Auto Scaling group reference

Add a resource named AutoScalingGroup of type AWS::AutoScaling::AutoScalingGroup with a minimal configuration including MinSize 1, MaxSize 3, and a placeholder LaunchConfigurationName set to MyLaunchConfig.

AWS

Resources:
  HighCPUNotification:
    Type: AWS::SNS::Topic
    Properties:
      TopicName: HighCPUNotification

  ScaleOutPolicy:
    Type: AWS::AutoScaling::ScalingPolicy
    Properties:
      AutoScalingGroupName: !Ref AutoScalingGroup
      PolicyType: SimpleScaling
      AdjustmentType: ChangeInCapacity
      ScalingAdjustment: 1
      Cooldown: 300

  HighCPUAlarm:
    Type: AWS::CloudWatch::Alarm
    Properties:
      AlarmName: HighCPUAlarm
      MetricName: CPUUtilization
      Namespace: AWS/EC2
      Statistic: Average
      Period: 300
      EvaluationPeriods: 2
      Threshold: 70
      ComparisonOperator: GreaterThanThreshold
      AlarmActions:
        - !Ref HighCPUNotification
        - !Ref ScaleOutPolicy
      Dimensions:
        - Name: AutoScalingGroupName
          Value: !Ref AutoScalingGroup

# Your code here to create AutoScalingGroup resource

Need a hint?

Use AWS::AutoScaling::AutoScalingGroup with MinSize, MaxSize, and LaunchConfigurationName.