A library consortium runs three control-plane nodes with stacked etcd. One control-plane VM fails. Why can the API often remain available?
Select an answer to reveal the explanation.
Short Explanation
Three etcd voters are like a three-judge panel—lose one and the other two can still outvote silence. That’s why odd counts and HA control planes tolerate a single missing member. Lose a second without recovery and quorum—and writes—go away fast.
Full Explanation
etcd requires a majority of members for consistent writes. A three-member cluster can survive one failure and still form quorum, allowing remaining apiservers to serve. This is a primary reason HA control planes use odd etcd member counts rather than a single member.