CloudWatch alarms in AWS - Mini Project: Build & Apply

Create a CloudWatch Alarm for CPU Utilization

📖 Scenario: You are managing a cloud server and want to monitor its CPU usage. If the CPU usage goes above a certain limit, you want to get notified automatically.

🎯 Goal: Build a CloudWatch alarm that watches the CPU utilization of an EC2 instance and triggers when the usage is above 70% for 5 minutes.

📋 What You'll Learn

Create a variable with the EC2 instance ID

Set a threshold value for CPU utilization

Define a CloudWatch alarm using the instance ID and threshold

Configure the alarm to trigger after 5 minutes of high CPU usage

💡 Why This Matters

🌍 Real World

CloudWatch alarms are used by cloud engineers to monitor server health and get alerts before problems affect users.

💼 Career

Knowing how to configure CloudWatch alarms is essential for roles like Cloud Engineer, DevOps Engineer, and Site Reliability Engineer.

1

Set the EC2 instance ID

Create a variable called instance_id and set it to the string "i-0abcd1234efgh5678" which represents your EC2 instance ID.

AWS

# Create a variable called instance_id with the value "i-0abcd1234efgh5678"
# Your code here

Need a hint?

The EC2 instance ID is a string. Use quotes around it.

2

Set the CPU utilization threshold

Create a variable called cpu_threshold and set it to the number 70 which will be the CPU usage percentage limit for the alarm.

AWS

instance_id = "i-0abcd1234efgh5678"
# Create a variable called cpu_threshold and set it to 70
# Your code here

Need a hint?

Threshold is a number without quotes.

3

Define the CloudWatch alarm configuration

Create a dictionary called cloudwatch_alarm with these exact keys and values: AlarmName set to "HighCPUAlarm", MetricName set to "CPUUtilization", Namespace set to "AWS/EC2", Statistic set to "Average", Period set to 60, EvaluationPeriods set to 5, Threshold set to the variable cpu_threshold, ComparisonOperator set to "GreaterThanThreshold", and Dimensions set to a list with one dictionary containing Name as "InstanceId" and Value as the variable instance_id.

AWS

instance_id = "i-0abcd1234efgh5678"
cpu_threshold = 70
# Create a dictionary called cloudwatch_alarm with the specified keys and values
# Your code here

Need a hint?

Use a dictionary with the exact keys and values. Use the variables for threshold and instance ID.

4

Add the alarm action configuration

Add a key called AlarmActions to the cloudwatch_alarm dictionary and set its value to a list containing the string "arn:aws:sns:us-east-1:123456789012:NotifyMe" which represents the SNS topic ARN to notify when the alarm triggers.

AWS

instance_id = "i-0abcd1234efgh5678"
cpu_threshold = 70
cloudwatch_alarm = {
    "AlarmName": "HighCPUAlarm",
    "MetricName": "CPUUtilization",
    "Namespace": "AWS/EC2",
    "Statistic": "Average",
    "Period": 60,
    "EvaluationPeriods": 5,
    "Threshold": cpu_threshold,
    "ComparisonOperator": "GreaterThanThreshold",
    "Dimensions": [
        {
            "Name": "InstanceId",
            "Value": instance_id
        }
    ]
}
# Add AlarmActions key with the SNS topic ARN
# Your code here

Need a hint?

AlarmActions is a list with one string ARN.