Investigate WebServer EC2 Instance reboot

[rachelekm]

Our WebServer EC2 instance has been repeatedly terminated and automatically relaunched over the last few days. Users have experienced a 503 error around this time and it's assumed to be because of the instance downtime. At this point the latest instance has been stable for over 24 hours, see CloudTrail event history below, but this is an unusual amount of relaunching for the time period and would be worth looking into what's causing the instances to terminate.

[BryanQuigley]

Can't get back to the events - but for next time: https://aws.amazon.com/premiumsupport/knowledge-center/auto-scaling-instance-how-terminated/ should help provide some more clues.