Domain 3: Monitoring and Logging Explained

Key Concepts

• Monitoring: The process of observing and collecting data to ensure system health and performance.
• Logging: The practice of recording events and activities for analysis and troubleshooting.
• Metrics: Quantitative measures used to track and assess the performance of systems.
• Alerts: Notifications triggered when specific conditions or thresholds are met.
• Dashboards: Visual representations of key metrics and data for real-time monitoring.
• CloudWatch: AWS service for monitoring and observability.
• CloudTrail: AWS service for logging API calls and actions.

Detailed Explanation

Monitoring

Monitoring involves continuously observing and collecting data to ensure that systems are functioning correctly. It helps in identifying issues early and maintaining optimal performance. AWS provides services like Amazon CloudWatch for comprehensive monitoring.

Logging

Logging is the practice of recording events and activities in a system. Logs provide valuable information for troubleshooting, auditing, and understanding system behavior. AWS services like Amazon CloudTrail and Amazon CloudWatch Logs are used for logging.

Metrics

Metrics are quantitative measures used to track and assess the performance of systems. Examples include CPU utilization, memory usage, and network throughput. CloudWatch collects and tracks metrics, allowing for detailed analysis and performance optimization.

Alerts

Alerts are notifications triggered when specific conditions or thresholds are met. For example, an alert can be set to notify when CPU usage exceeds 80%. CloudWatch Alarms can be configured to send alerts via email, SMS, or other channels.

Dashboards

Dashboards provide visual representations of key metrics and data for real-time monitoring. They help in quickly assessing the health and performance of systems. CloudWatch Dashboards allow users to create custom views of their monitoring data.

CloudWatch

Amazon CloudWatch is a monitoring and observability service that provides data and actionable insights for AWS, hybrid, and on-premises applications and infrastructure. It collects and tracks metrics, logs, and events.

CloudTrail

Amazon CloudTrail is a service that logs API calls and actions taken by users, roles, or AWS services. It provides a history of AWS account activity for auditing, security monitoring, and operational troubleshooting.

Examples and Analogies

Example: CloudWatch Metrics

Below is an example of creating a CloudWatch metric to track CPU utilization:

{
    "Namespace": "MyApplication",
    "MetricData": [
        {
            "MetricName": "CPUUtilization",
            "Dimensions": [
                {
                    "Name": "InstanceId",
                    "Value": "i-1234567890abcdef0"
                }
            ],
            "Value": 75.0,
            "Unit": "Percent"
        }
    ]
}
    

Example: CloudTrail Logging

Here is an example of enabling CloudTrail logging for an AWS account:

aws cloudtrail create-trail --name MyCloudTrail --s3-bucket-name my-bucket
aws cloudtrail start-logging --name MyCloudTrail
    

Analogy: Car Dashboard

Think of monitoring and logging as the dashboard and logs of a car. The dashboard provides real-time metrics like speed, fuel level, and engine temperature, helping the driver assess the car's health. Logs are like the car's maintenance records, detailing past events and issues for troubleshooting and analysis.