Amazon CloudWatch Metrics and Dashboards

Amazon CloudWatch is the central monitoring and observability service in AWS. It collects metrics, logs, and events from virtually every AWS resource and allows you to visualise them in dashboards, set alarms, and take automated actions. In this lesson we focus on the two foundational building blocks: metrics and dashboards.

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What Is a CloudWatch Metric?

A metric is a time-ordered set of data points that represents a variable you want to monitor — for example, the CPU utilisation of an EC2 instance or the number of messages in an SQS queue.

Every metric is defined by three pieces of information:

Component	Description	Example
Namespace	A container that groups related metrics	AWS/EC2, AWS/RDS, Custom/MyApp
Metric name	The measurement being tracked	CPUUtilization, RequestCount
Dimensions	Key-value pairs that identify the specific resource	InstanceId=i-0abcdef1234567890

Standard vs Custom Metrics

Standard metrics are published automatically by AWS services at no extra cost. For example, every EC2 instance emits CPUUtilization, NetworkIn, NetworkOut, DiskReadOps, and more — all at five-minute granularity by default.