CHAPTER 10.4 – Based on the scenario in the lab does the health check depends on a certain type of traffic say HTTP in this case) or it depends on the actual health of the EC2 instance ? Thanks.
If you are talking about the health check embedded in an ALB, it will query a specific HTTP endpoint on your machine (that you define) in order to check if your service is currently available. If this healthcheck returns 200 , the ALB will still send traffic to this machine, if not, it will stop sending traffic to it.
To give another example, imagine one of your colleagues deleted the file of this healthcheck (like for example the file healthcheck.html) and your instance has no issue (like CPU/RAM issue), the ALB will not send any traffic to this instance.
I hope this message helped you
The creation of the health checks is for some reason not shown in the video, but you have to create them before creating the Failover record, in the "Health checks" section of the Route 53 menu on the left.