Observability - Liveness Probes

Question 1

What problems do liveness probes solve?

Answer 1

• an application running in an container could be stuck because of a bug
• would still be shown as a ready container with traffic routed to it
• liveness probe can help

Question 2

What can liveness probes do?

Answer 2

• periodically test if the application within a container is acutally healthy
• if unhealthy, container is destroyed and recreated

Question 3

What kind of Liveness probes exist?

Answer 3

• HTTP Tests against URL
• TCP Test for socket
• exec command to perform certain test

Question 4

How are Liveness probes defined?

Answer 4

like to Readiness Probes:

...
spec:
 containers:
  - name:
 livenessProbe:
  httpGet:
	 path:
	 port:
	////
	tcpSocket:
	 port: 3306
	 ////
	exec:
	 command:
	  - cat
	  - /app/is_healthy