CloudWatch

Amazon CloudWatch is a monitoring and observability service that provides data and actionable insights for AWS resources and applications.

More Information

• https://aws.amazon.com/cloudwatch

Metrics

• Data points about the performance of your systems
• AWS services automatically send metrics to CloudWatch (e.g. EC2 CPU utilization, ELB request count)
• Custom metrics can be published via the CloudWatch API
• Default monitoring interval: 5 minutes (basic); 1 minute (detailed, may incur additional cost)
• Metrics are retained for 15 months

More Information

• https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/working_with_metrics.html

Alarms

• Watch a single metric over a specified time period
• Perform one or more actions based on the metric value relative to a threshold
• Alarm states: OK, ALARM, INSUFFICIENT_DATA
• Actions can include: sending an SNS notification, triggering an Auto Scaling action, or executing an EC2 action (stop, terminate, reboot)

More Information

• https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/AlarmThatSendsEmail.html

Logs

• Centralized log collection from AWS services and applications
• Key concepts:
  • Log group: a collection of log streams that share the same retention and monitoring settings
  • Log stream: a sequence of log events from the same source
  • Log event: a record of activity with a timestamp and message
• Log data can be exported to S3 or streamed to Lambda, Elasticsearch, or other destinations
• Retention can be configured from 1 day to indefinite (never expire)

More Information

• https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/WhatIsCloudWatchLogs.html

Log Insights

• Interactive query language for searching and analyzing log data
• Automatically discovers fields in JSON logs
• Supports aggregations, filters, and visualizations

More Information

• https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/AnalyzingLogData.html

Dashboards

• Customizable pages in the CloudWatch console for monitoring resources in a single view
• Can include metrics graphs, text widgets, alarms, and log query results
• Dashboards can be shared across accounts

More Information

• https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CloudWatch_Dashboards.html

EventBridge (formerly CloudWatch Events)

• Serverless event bus that delivers events from AWS services, custom applications, and SaaS partners
• Rules match incoming events and route them to targets (e.g. Lambda, SQS, SNS, Step Functions)
• Supports scheduled rules (cron/rate expressions) for periodic tasks

More Information

• https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-what-is.html