---
upgrade:
  - |
    The default for ``[glance] num_retries`` has changed from ``0`` to ``3``.
    The option controls how many times to retry a Glance API call in response
    to a HTTP connection failure. When deploying Glance behind HAproxy it is
    possible for a response to arrive just after the HAproxy idle time. As a
    result, an exception will be raised when the connection is closed resulting
    in a failed request. By increasing the default value, Nova can be more
    resilient to this scenario were HAproxy is misconfigured by retrying the
    request.