How does the kubernetes apiserver handle etcd being down?

7/25/2017

Im planing to migrate from etcd2 to etcd3. I've researched and come to this conclution

  • change listen port so apiserver cannot write
  • upgrade all nodes to etcd3
  • use etcdctl migrate to migrate the data
  • use cluster/images/etcd/attachlease/attachlease.go to attach TTL to /registry/events
  • change back to correct listening port

However i would like to know what happens during the time apiserver cannot talk to etcd. Does the pod scheduling work etc?

-- jonaz
kubernetes

1 Answer

7/25/2017

The control plane is down during an etcd outage (scheduling is also down). Pods that are already scheduled continue running and Services also continue to work.

I suggest extensive testing before doing this in production.

-- Janos Lenart
Source: StackOverflow