Kubernetes cluster recovery after linux host reboot

7/15/2019

We are still in a design phase to move away from monolithic architecture towards Microservices with Docker and Kubernetes. We did some basic research on Docker and Kubernetes and got some understanding. We still have couple of open question considering we will be creating K8s cluster with multiple Linux hosts (due to some reason we can't think about Cloud right now) .

Consider a scenario where we have K8s Cluster spanning over multiple linux hosts (5+).

1) If one of the linux worker node crashes and once we bring it back, does enabling kubelet as part of systemctl in advance will be sufficient to bring up required K8s jobs so that it be detected by master again?

2) I believe once worker node is crashed (X pods), after the pod eviction timeout master will reschedule those X pods into some other healthy node(s). Once the node is UP it won't do any deployment of X pods as master already scheduled to other node but will be ready to accept new requests from Master.

Is this correct ?

-- BinaryBoy
kubernetes
kubernetes-ingress

1 Answer

7/15/2019
  1. Yes, should be the default behavior, check your Cluster deployment tool.

  2. Yes, Kubernetes handles these things automatically for Deployments. For StatefulSets (with local volumes) and DaemonSets things can be node specific and Kubernetes will wait for the node to come back.

Better to create a test environment and see/test the failure scenarios

-- Ijaz Ahmad Khan
Source: StackOverflow