Cloudwatch : Alarm

• Trigger notifications for any metric value
• set condtion : %, min,max, etc
• set evaluation period.
• states
• ok
• in-alarm
• insufficient-data
• action :
• ec2 : reboot,recover , stop
• ASG
• SNS alert : most common
• ...
• composite alarm
• alarm1 AND/OR alarm2
• help to reduce noise

• 

• alarm can be created on:

• any metric
  • inbuild
  • custom: eg log metric-filter
• Ec2:status check
  • instance status
  • attached EBS status
  • ...
• ...

---

D. demo

// 5 . create alarm
- launch ec2-i1 
- CW > create metric-1
  - add ec2-i1
  - type : cpu
  - every 5 min, 3 of 3
  - greater than 90%
  - state action:
    - ok > action:
    - in-alarrm > action : terminate ec2-i1
    - insufficient-data > action :
     >> manually update state from aws-cli

...

Cli

• set-alarm-state

  This is particularly useful for testing purposes or manually managing alarm 
  
  aws cloudwatch set-alarm-state \
      --alarm-name <alarm-name> \
      --state-value <state-value> \  # OK, ALARM, or INSUFFICIENT_DATA
      --state-reason "<reason>"