On Fri, 11 Feb 2011, Paul Voccio wrote: > Below. > > On 2/11/11 2:30 PM, "Scott Moser" <smo...@ubuntu.com> wrote: > > >On Fri, 11 Feb 2011, Vishvananda Ishaya wrote: > > > >> Agreed. By default lets put things into nova because it makes > >> development and visibility much easier. As eric mentioned, we can > >> always break it out later. > > > >The stability of the API for communication between the hypervisor platform > >and an instance is very important. The ability to quickly change it > >should not be the primary reason that you decide where to land the code. > > > >Once you're past the immediate bringup, you're going to need to maintain > >backward compatibility. You'll have images running on openstack > >installations that have old versions of the agent, and no real option to > >modify them. You need to get this right, and minimal is better. > > One of the features of the agent is to return features is knows about and > return a 'not implemented' if it gets a request it can't complete. Another > feature of the agent is to be passed an option to update itself, given a > url and a md5 hash.
So thats a required feature of all potential agents ? It was initially stated that the agent was necessary to setup networking. I assume that 'url' above could potentially be cdrom://foo.bar.gz , though. Either way, I surely hope that your argument is not suggesting that you can change the API willy-nilly because all the agents in existing guests should just be able to update themselves. Another thing that Amazon did well, was their host->guest communication, which takes place as the "metadata service" is entirely versioned. Ie: $ wget http://instance-data/ -O - -q; echo 1.0 2007-01-19 2007-03-01 2007-08-29 2007-10-10 2007-12-15 2008-02-01 2008-09-01 2009-04-04 2011-01-01 latest Each version is maintained indefinitely. I realize that their metadata service is simple, but again, other than networking setup, I really think its completely sufficient. I don't see a necessity for making a lot of complex interactions between hypevisor and guest. All that does is make it more difficult to develop guests. I won't object much more, but please, please keep the guest requirements and expectations to a minimum. I'm involved in the development of images for such a platform, and I do not want to be limited by expectations that the host has upon our images. _______________________________________________ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp