If you don't give your two host cluster enough time to "feel healthy", it will generate an error if you do operations within five seconds. This is a regression and the five seconds is also quite arbitrary. This is detailed at: https://github.com/coreos/etcd/issues/6305 This seems to be a bit of a race condition, even with a 10s timer, so this also disables the StrictReconfigCheck. Re-enable this as soon as possible.