On Fri, Dec 02, 2011 at 02:54:17AM +0200, Dan Kenigsberg wrote:
On Tue, Nov 29, 2011 at 07:21:08PM +0000, Daniel P. Berrange wrote:
On Tue, Nov 29, 2011 at 01:11:18PM -0600, Adam Litke wrote:
On Tue, Nov 29, 2011 at 05:44:23PM +0000, Daniel P. Berrange wrote:
On Tue, Nov 29, 2011 at 11:18:42AM -0600, Adam Litke wrote:
On Tue, Nov 29, 2011 at 04:50:19PM +0000, Daniel P. Berrange wrote:
On Tue, Nov 29, 2011 at 10:29:41AM -0600, Adam Litke wrote: > After discussing MOM / VDSM integration at length, two different strategies have > emerged. I will call them Plan A and Plan B: > > Plan A: MOM integration at the OS/Packaging level > Plan B: MOM integration as a new VDSM thread > > This RFC is about Plan A. I will start another thread to discuss Plan B once I > have properly prototyped the idea in code. > > Integration VDSM and MOM at the OS level is by far the simpler and least > intrusive option. As you can see from the included patch, the changes to vdsm > are very limited. In this model, VDSM interacts with MOM in the same way as it > uses libvirt. Upon installation, VDSM installs its own MOM configuration file > and restarts the MOM daemon (which continues to exist as an independent > system-level daemon). Once restarted, MOM will load its policy from the VDSM > configuration directory. > > Pros: > - Simple and unobtrusive to either MOM or VDSM > - Clean API with no duplication or layering > - Maintain flexibility to tighten integration in the future
Agreement is boring, but I prefer this approach, too. Vdsm is begging for a modular breakup as it is; if we import mom into Vdsm, in no time we would be tempted to avoid Vdsm API and create new dependencies.
Heh -- Boring? Maybe. Welcomed by me? Definitely! Thanks for your comments.
One comment regarding the suggested patch: I do not understand what is so special about Vdsm that it should carry its own momd policy. It is not like momd has a gazillion of competing policies... I'd rather have momd deployed with all of the handful of policies we can device. Vdsm's task would be only to configure the default policy for momd to use on boot.
Sure, that's fine. Actually for this patch I just copied the existing MOM policy to demonstrate the idea of vdsm shipping a policy. If we want it to remain with MOM that is fine by me.