[ovirt-devel] Adding support for 3.6 in engine database

[Alon Bar-Lev]

----- Original Message -----
> From: "Oved Ourfali" <ovedo at redhat.com>
> To: "Dan Kenigsberg" <danken at redhat.com>
> Cc: "engine-devel at ovirt.org" <devel at ovirt.org>
> Sent: Wednesday, January 14, 2015 5:19:03 PM
> Subject: Re: [ovirt-devel] Adding support for 3.6 in engine database
> 
> 
> 
> ----- Original Message -----
> > From: "Dan Kenigsberg" <danken at redhat.com>
> > To: "Oved Ourfali" <ovedo at redhat.com>
> > Cc: "engine-devel at ovirt.org" <devel at ovirt.org>
> > Sent: Wednesday, January 14, 2015 5:03:12 PM
> > Subject: Re: [ovirt-devel] Adding support for 3.6 in engine database
> > 
> > On Wed, Jan 14, 2015 at 08:19:00AM -0500, Oved Ourfali wrote:
> > > 
> > > 
> > > ----- Original Message -----
> > > > From: "Dan Kenigsberg" <danken at redhat.com>
> > > > To: "Oved Ourfali" <ovedo at redhat.com>, fsimonce at redhat.com
> > > > Cc: "engine-devel at ovirt.org" <devel at ovirt.org>
> > > > Sent: Wednesday, January 14, 2015 3:15:02 PM
> > > > Subject: Re: [ovirt-devel] Adding support for 3.6 in engine database
> > > > 
> > > > On Thu, Jan 08, 2015 at 08:46:09AM -0500, Oved Ourfali wrote:
> > > > > 
> > > > > 
> > > > > ----- Original Message -----
> > > > > > From: "Eli Mesika" <emesika at redhat.com>
> > > > > > To: "Lior Vernia" <lvernia at redhat.com>, "Oved Ourfali"
> > > > > > <oourfali at redhat.com>
> > > > > > Cc: "engine-devel at ovirt.org" <devel at ovirt.org>, "Dan Kenigsberg"
> > > > > > <danken at redhat.com>, "Yaniv Bronheim"
> > > > > > <ybronhei at redhat.com>
> > > > > > Sent: Thursday, January 8, 2015 3:41:31 PM
> > > > > > Subject: Re: [ovirt-devel] Adding support for 3.6 in engine
> > > > > > database
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > ----- Original Message -----
> > > > > > > From: "Lior Vernia" <lvernia at redhat.com>
> > > > > > > To: "Eli Mesika" <emesika at redhat.com>
> > > > > > > Cc: "engine-devel at ovirt.org" <devel at ovirt.org>, "Dan Kenigsberg"
> > > > > > > <danken at redhat.com>, "Yaniv Bronheim"
> > > > > > > <ybronhei at redhat.com>
> > > > > > > Sent: Thursday, January 8, 2015 3:08:24 PM
> > > > > > > Subject: Re: [ovirt-devel] Adding support for 3.6 in engine
> > > > > > > database
> > > > > > > 
> > > > > > > Tried to work with it, and noticed that:
> > > > > > > 1. The engine doesn't list 4.17 as a supported vdsm version.
> > > > > > > 2. 4.17 vdsm doesn't report 3.6 as a supported engine version.
> > > > > > > 
> > > > > > > This basically means that no host could be operational in a 3.6
> > > > > > > cluster,
> > > > > > > as to my understanding 4.17 is exactly the version supporting 3.6
> > > > > > > functionality.
> > > > > > > 
> > > > > > > May I send a fix for (1), or is there any argument against? And
> > > > > > > who
> > > > > > > could take care of (2)?
> > > > > > 
> > > > > > I had understood deom Oved that this is 4.16 see patch
> > > > > > http://gerrit.ovirt.org/#/c/36511/
> > > > > > Oved ???
> > > > > > 
> > > > > 
> > > > > I don't know when we should add 4.17. I remember there is some
> > > > > "policy"
> > > > > for
> > > > > that.
> > > > > Dan?
> > > > 
> > > > Yes, there is.
> > > > 
> > > > Vdsm would like to declare its support of clusterLevel 3.6 only when it
> > > > actually does. This is not yet the case, as we are not yet in 3.6
> > > > feature freeze (heck, we're not yet in feature definition).
> > > > 
> > > > To test cluster level 3.6 on the master branch, someone has to "lie".
> > > > 
> > > > It may be Vdsm (by claiming that it supports 3.6 while it does
> > > > not) or Engine (by allowing vdsm 4.17 into cluster 3.6, even though it
> > > > does not).
> > > > 
> > > > I prefer the latter, as the Engine-side hack is eaiser to undo on a
> > > > distributed system. If today's Vdsm claims that it already support 3.6,
> > > > future Engines would add it to their cluster, only to find that random
> > > > APIs fails. If the hack is Engine-side, it would be gone when 3.6
> > > > reaches feature freeze.
> > > > 
> > > 
> > > We don't have a mechanism to "allow" specific version of VDSM to a
> > > specific
> > > cluster level.
> > > For this we only rely on the reported supported cluster levels.
> > 
> > I know. I'm asking Engine to add it.
> 
> The logic in the engine is complex and confusing enough, without adding any
> other configuration to it, so I prefer to leave it as is.
> I don't see why we can't add the cluster levels to the supported VDSM cluster
> levels, as we didn't release any official VDSM version yet, so what's the
> issue with that?
> The fact that engine master has 3.6 cluster level doesn't mean it is
> supported either. It will be once 3.6 is released.

this is old discussion... if master work toward a release or version is determine near release.
there are two policies in our project, one for vdsm - determine versions near release, and the other is to all other components which is working toward a release.
I believe that working toward a release is a better approach especially when components are a coupled.