2.1.1. Amazon CloudWatch Fundamentals

💡 First Principle: Amazon CloudWatch provides a comprehensive and scalable monitoring service that collects operational data (metrics, logs, events) from AWS and on-premises resources, enabling real-time insights and automated actions.

Scenario: You need to monitor the CPU utilization of your EC2 instances, collect application logs from your Lambda functions, and set up alerts if the CPU usage exceeds a certain threshold.

Amazon CloudWatch is the primary monitoring and observability service for AWS. For SysOps Administrators, it's the central hub for understanding the health, performance, and operational status of their entire AWS environment.

Key CloudWatch Fundamentals:

• Metrics: (Time-series data points that represent a measurement of a particular aspect of a resource or application.) Collects standard metrics from AWS services (e.g., EC2 CPU Utilization, Lambda invocations, DynamoDB throttled requests). You can also publish custom metrics from your applications or scripts.
• Logs: (Centralizes logs from various sources, such as Lambda functions, EC2 instances (via CloudWatch Agent), and custom applications.) Allows for real-time monitoring and powerful searching.
• Events: (Represents a change in your AWS environment that indicates a change in a resource or condition.) Captures events from AWS services and custom applications, enabling event-driven automation.
• Alarms: (Monitors metrics and automatically triggers actions when a defined threshold is breached.) Notifies administrators of critical issues.
• Dashboards: Create customizable visualizations of metrics and alarms for operational oversight.

⚠️ Common Pitfall: Not installing the CloudWatch Agent on EC2 instances to collect detailed OS-level metrics (e.g., memory, disk utilization) or application logs.

Key Trade-Offs: Using standard metrics (simpler, free for basic) versus custom metrics (deeper insight, but requires instrumentation and incurs cost).

Reflection Question: How does Amazon CloudWatch, by providing comprehensive data collection (metrics, logs) and automated alerting (alarms), enable you as a SysOps Administrator to gain real-time insights into your AWS environment and proactively respond to operational events?