Comment 1 for bug 1441386

So looks like keystone-manage CLI have a slimmed down version of load_backends

https://github.com/openstack/keystone/blob/master/keystone/cli.py#L339

which doesn't have the cache configured

https://github.com/openstack/keystone/blob/master/keystone/backends.py#L33

So we have two choices

1. add the cache configuration back to the slimmed down version. Drawback is that we have to perpetually maintaining two different versions of load_backends().
2. get rid of the slimmed down version and directly use the fat version in keystone/backends.py. Drawback is that it will contain extra fat.

But since keystone-manager CLI is something that will be used sparingly, I think we should go for option #2.