There is a common issue 19557 in the etcd v3.5 to v3.6 upgrade that may cause the upgrade process to fail. You can find detailed information and related discussions in the issue. TL; DR Users are required to first upgrade to etcd v3.5.20 (or a higher patch version) before upgrading to etcd v3.6.0. Failure to do so may result in an unsuccessful upgrade. What’s the symptom? When upgrading a multi-member etcd cluster from a version between v3.5.1 and v3.5.19 to v3.6.0, the upgrade may fail due...
