CloudWatch Metrics and Alarms

1. Introduction

Amazon CloudWatch is a monitoring and observability service provided by AWS that offers metrics and alarms to track the performance and health of AWS resources and applications. This lesson will cover the key concepts of CloudWatch metrics and alarms, how to set them up, and best practices for effective monitoring.

2. Understanding Metrics

Metrics are data points that CloudWatch collects from your AWS resources. They provide insights into the performance and operational health of your applications. Each metric consists of:

• Namespace: A container for CloudWatch metrics.
• Metric Name: A name for the metric being collected.
• Dimensions: Name/value pairs that define the metric's characteristics.
• Statistics: Data aggregation types such as Average, Sum, Minimum, and Maximum.
• Time Stamp: The time at which the metric was collected.

2.1 Example of a Metric

{
    "Namespace": "AWS/EC2",
    "MetricName": "CPUUtilization",
    "Dimensions": [
        {
            "Name": "InstanceId",
            "Value": "i-1234567890abcdef0"
        }
    ],
    "Statistics": ["Average", "Maximum"],
    "Unit": "Percent"
}
            

3. Creating Alarms

Alarms are used to set thresholds on metrics and can trigger actions when these thresholds are crossed. To create an alarm:

1. Navigate to the CloudWatch console.
2. Select "Alarms" from the left sidebar.
3. Click on "Create Alarm".
4. Choose a metric to monitor.
5. Define the conditions for the alarm (threshold, period, etc.).
6. Select actions to take when the alarm state changes.
7. Review and create the alarm.

3.1 Example of Creating an Alarm

aws cloudwatch put-metric-alarm --alarm-name "HighCPUUtilization" \
    --metric-name "CPUUtilization" \
    --namespace "AWS/EC2" \
    --statistic "Average" \
    --period 300 \
    --threshold 80 \
    --comparison-operator "GreaterThanThreshold" \
    --dimensions "Name=InstanceId,Value=i-1234567890abcdef0" \
    --evaluation-periods 1 \
    --alarm-actions "arn:aws:sns:us-west-2:123456789012:MyTopic" \
    --unit "Percent"
            

4. Best Practices

Here are some best practices to consider when working with CloudWatch Metrics and Alarms:

• Regularly review and adjust alarm thresholds based on application performance.
• Use SNS notifications to alert responsible teams for quick action.
• Group related metrics into namespaces for better organization.
• Implement dashboard views to visualize metrics and alarms effectively.

5. FAQ