---
features:
  - Added RPC backward compatibility layer similar to the
    one implemented in Nova. This means that Cinder
    services can be upgraded one-by-one without breakage.
    After all the services are upgraded SIGHUP signals
    should be issued to all the services to signal them
    to reload cached minimum RPC versions. Alternative
    is of course restart of them. Please note that
    cinder-api service doesn't support SIGHUP yet.
    Please also take into account that all the rolling
    upgrades capabilities are considered tech preview,
    as we don't have a CI testing it yet.
upgrade:
  - Starting from Mitaka release Cinder is having a tech
    preview of rolling upgrades support.