Well sometimes you get to the point that you’ve been using Amazon CloudWatch or Detailed Monitor option in your EC2 Instance and you know it will cost you if you create some alerts like an alarm to send you an email to let you know your CPU is over 50% of average or whatever the number you defined! and clearly when you get the email you realize that you have know idea why your CPU is over 50% or 60%!
Yes, you still need something else to monitor your server to see what went wrong or just to see what is what and what happened at that moment to trigger that alert.
Will continue to tell you how I use Zabbix and SYSSAT to see a lot more details than a simple graph on CloudWatch.