So I'm trying to setup composite alarms on AWS. So far, I have most of it set up. At the moment, I have a composite alarm set up with 3 alarms. If any 2 of these 3 alarms trigger, then the composite alarm also triggers. This part works fine.

However, I am having trouble with part of my use case. I'd also like to make it so that if one of these alarms within the composite alarm stays in alarm for over a certain period of time, then an alert is also sent out.

Here's an example of the situation:

2 out of the 3 alarms turn on in any time period: Alert should be sent

1 out of the 3 alarms turn on for under a certain time period: Alert should not be sent

1 out of the 3 alarms turn on for over a certain time period: Alert should be sent

I've tried looking into the settings available on the alarms themselves, and there doesn't seem to be an option for what I'm trying to do.

I'm wondering if this would require a lambda function? Is it possible for a lambda function to keep track of how long an alarm has been in alarm?

CodePudding user response：

As talked in the comment section above, I am providing you with a possible solution to your problem. The only blocker is that you can't have different time frame for the alarms, both should be the same.
So you will have (example) Alarm 1(cpu) if for 15 min it's over 60%. Alarm 2(EFS connections) if for 15 min there are more than 10 connections.
Now the alarm will go off when both the statements are true. Also the alarm will go off when only Alarm 1 goes off.
This is how you are going to make this alarm.

As for testing, it depends on what type of alarms you are making. For example cpu and ram increament methods are widely available on stackoverflow.
Also with aws cli you can change state of an alarm. It's usually for a very small amount of time, maybe 10 seconds.
aws cloudwatch set-alarm-state --alarm-name "myalarm" --state-value ALARM --state-reason "testing purposes".
You need to find a method which can suite your needs better.