Regarding blueprint version-rpc-messages<https://blueprints.launchpad.net/openstack/?searchtext=version-rpc-messages>, I have some thoughts on enhancing it for a backward compatibility problem people are having with blueprint amqp-rpc-fast-reply-queue<https://blueprints.launchpad.net/openstack/?searchtext=amqp-rpc-fast-reply-queue> Here is what I propose and I mention in the code review notes: "Perhaps another Grizzly blueprint could be written to augment Russel Bryant's version-rpc-messages envelope idea to enabled it by default. Today it is disabled with a TODO to enable it after Grizzly. Along with this make the necessary changes to detect an RPC failure caused by New->Old versions and reissue the RPC without the envelope. Then make my blueprint dependent upon that one. And (optionally) perhaps even make a change in the checking of the envelope to look for unexpected content in that envelope. For example, if we decide in the future to add an implementation version or whatever, that a version that supported the envelope, but not the new content would fail the RPC." What do you think? Does it have problems? I see an advantage. Not only would it work for G to (<G) versions. It would also work for (>G) to (<G) versions. blueprint version-rpc-messages <https://blueprints.launchpad.net/openstack/?searchtext=version-rpc-messages>loses interoperability with (<G) after Grizzly. Maybe that isn't a valid concern, but one worth mentioning. Ray -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20130124/787e7f89/attachment.html>