Comment 3 for bug 1731828

The need for this feature, for myself at least is related to this bug:

https://bugs.launchpad.net/ceilometer/+bug/1665449

Which we are now hitting on production clouds using charm versions >= 17.11

There are three options that can be set for "notification_format" in [oslo_messaging_notifications]:

['unversioned', 'versioned', 'both']

Of which 'both' is the default

https://github.com/openstack/nova/blob/stable/pike/nova/conf/notifications.py#L88-L105

As there is no consumer, I'd be inclined to set "unversioned" as the default until LP#1665449 is resolved.