Health checks

Instance health checks

• System: network, power, hardware issues (AWS problem)
• Instance: Incorrect configuration, out of memory, corrupted file system (our problem)

Target group health checks

• Come from the load balancer
• Pings an endpoint

WTF is a target group

A grouping of apps that will receive load balanced traffic

• Healthy threshold: if you're unhealthy, the number of consecutive healthy checks needed to be healthy.
• Unhealthy: the opposite
• Timeout: how long the check waits
• Interval: how long to wait between checks