Hey, For the first time (that I'm aware of) we have a request to include a backport on the stable branch which includes a change to the RPC API: https://review.openstack.org/14754 This is troublesome for a couple of reasons: 1) People upgrading to a version which includes this change would need to be aware that they should update their compute services before updating their API services 2) While in this case we're backporting the first RPC API change since Folsom (i.e. version 2.2 was in Folsom, this is version 2.3) if we were backporting a later API version we would have to give up on retaining Folsom compatibility in Grizzly In this particular case, I'm somewhat hopeful we might be able to figure out a fix which doesn't involve the API change but that remains to be seen. Any ideas? Cheers, Mark.