References:
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/monitoring-system-instance-status-check.html
https://docs.aws.amazon.com/elasticloadbalancing/latest/classic/elb-healthchecks.html
https://docs.aws.amazon.com/elasticloadbalancing/latest/application/target-group-health-checks.html
https://docs.aws.amazon.com/elasticloadbalancing/latest/network/target-group-health-checks.html
https://docs.aws.amazon.com/autoscaling/ec2/userguide/healthcheck.html