CloudWatch Cheat Sheet

  • An umbrella service consists of independent sub-services, this document refers to the Metrics sub-service (where the API is under CloudWatch name, other sub-services APIs are under different names)
  • See also
    • CloudWatch Logs Cheat Sheet
    • EventBridge Cheat Sheet (previously CloudWatch Events)

Metrics

  • Can collect service and application metrics
  • For EC2, only hardware metrics like CPU Utilization, Disk I/O and Network I/O are collected, to collect system metrics like Disk Usage, Memory Usage, user has to install CloudWatch Agent on the system
  • Standard metrics collection granularity = 1 minutes; high resolution = 1 second 🎓

Alarms

  • Alarms are triggered by metrics and responded with an action
  • Multiple alarms can be combined into a composite alarm, e.g. trigger main alarm when all underlying alarms enters ALARM state
  • If X Datapoints within last Y Evaluation Periods breaches the Threshold, the alarm enters ALARM state
Alarm threshold trigger alarm
  • Standard alarm period length = multiple of 1 minute; high resolution alarm (must be set on high resolution metrics) = multiple of 10, 30 seconds, or 1 minute