Hooking Into the AWS Shutdown Flow
When you are autoscaling lots of spot instances, or kill off systems during a code deploy, you don’t care if the system goes away, because that is what you intended to happen. Normally when spots or on-demand instances terminate by either a ec2kill command, price-terminated or killed by the ELB/Auto-Scaler, they receive a poweroff command sent by the hypervisor. This blog describes how we tell our collector agent to remove the system from the watch list, remove all probing associated with the system (http, ping, etc) and send a blurb through Hipchat saying this system is powering off.