The TTL in the architecture diagram is not in the code

[scytacki]

The architecture diagram shows the lambda code doing a TTL check. It doesn't seem to be doing that anymore.

I'd guess the TTL isn't necessary because the Lifecycle hook has a HeartbeatTimeout of 900. And from what I can tell the lambda function never sends a heartbeat. It only sends a completion message. So after 900 seconds the autoscaller will terminate the instance. And then the lambda function will see the instance doesn't exist anymore and it will stop repeating.