---
deprecations:
  - >
    With the release of 4.2.0 of keystonemiddleware we no longer recommend
    using the in-process token cache. In-process caching may result in
    inconsistent validation, poor UX and race conditions.

    It is recommended that the `memcached_servers` option is set in the
    `keystone_authtoken` configuration section of the various services (e.g.
    nova, glance, ...) with the endpoint of running memcached server(s).

    When the feature is removed, not setting the `memcached_servers`
    option will cause keystone to validate tokens more frequently, increasing
    load. In production, use of caching is highly recommended.

    This feature is deprecated as of 4.2.0 and is targeted for removal in
    keystonemiddleware 5.0.0 or in the `O` development cycle, whichever is
    later.