learning_ops_kubernetes.md

path	title
/learnings/ops_kubernetes	Learnings: Ops: Kubernetes

Table Of Contents

• Difference between Liviness and Readiness checks
  • See also
• See also
• kubectl get pods

Difference between Liviness and Readiness checks

https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-probes/

K8S Readiness Probe Fails Stops Routing traffic to the pod Liveness Probe fails Kubernetes restarts the failed container Readiness probe succeeds Kubernetes starts routing traffic to the pod again

So when is the pod ready for traffic from MS perspective? That should be Readiness Probe Configuration so this means any external connections needed are made etc Liveness lets us know if app is alive or dead. App could be booted but not ready for traffic

These should be off the separate channel off the main thread (but observing the traffic thread(s) somehow cleverly in the case of readiness)

See also

• https://github.com/rwilcox/k8_spring_actuators

See also

• Learning_Ops_Java_Docker
• Learning_Ops_Java_Docker_JMX_Considerations

kubectl get pods

  NAME                          DESIRED   CURRENT   READY   AGE
  nginx-deployment-2035384211   3         3         3       18s

Notice that the name of the ReplicaSet is always formatted as [DEPLOYMENT-NAME]-[POD-TEMPLATE-HASH-VALUE]. The hash value is automatically generated when the Deployment is created.