[openstack-dev] [OpenStack-dev][Blueprints][version-rpc-messages][amqp-rpc-fast-reply-queue]Proposal to recover from version mismatch

Ray Pekowski pekowski at gmail.com
Fri Jan 25 04:10:36 UTC 2013

Here are better links to both blueprints:

On Thu, Jan 24, 2013 at 10:00 PM, Ray Pekowski <pekowski at gmail.com> wrote:

> 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/20130124/62a8b063/attachment.html>

More information about the OpenStack-dev mailing list