[Engine-devel] Setting cluster CPU

[Oved Ourfalli]

----- Original Message -----
> From: "Michal Skrivanek" <michal.skrivanek at redhat.com>
> To: "Oved Ourfalli" <ovedo at redhat.com>
> Cc: "Sandro Bonazzola" <sbonazzo at redhat.com>, "Roy Golan" <rgolan at redhat.com>, "engine-devel"
> <engine-devel at ovirt.org>
> Sent: Wednesday, December 11, 2013 8:45:41 AM
> Subject: Re: [Engine-devel] Setting cluster CPU
> 
> 
> On Dec 11, 2013, at 08:18 , Oved Ourfalli <ovedo at redhat.com> wrote:
> 
> > 
> > 
> > ----- Original Message -----
> >> From: "Michal Skrivanek" <michal.skrivanek at redhat.com>
> >> To: "Oved Ourfalli" <ovedo at redhat.com>, "Sandro Bonazzola"
> >> <sbonazzo at redhat.com>
> >> Cc: "Roy Golan" <rgolan at redhat.com>, "engine-devel"
> >> <engine-devel at ovirt.org>
> >> Sent: Tuesday, December 10, 2013 8:01:08 PM
> >> Subject: Re: [Engine-devel] Setting cluster CPU
> >> 
> >> 
> >> On Dec 10, 2013, at 09:14 , Oved Ourfalli <ovedo at redhat.com> wrote:
> >> 
> >>> 
> >>> 
> >>> ----- Original Message -----
> >>>> From: "Sandro Bonazzola" <sbonazzo at redhat.com>
> >>>> To: "Michal Skrivanek" <michal.skrivanek at redhat.com>, "Oved Ourfalli"
> >>>> <ovedo at redhat.com>, "Roy Golan"
> >>>> <rgolan at redhat.com>
> >>>> Cc: "engine-devel" <engine-devel at ovirt.org>
> >>>> Sent: Tuesday, December 10, 2013 9:12:14 AM
> >>>> Subject: Re: [Engine-devel] Setting cluster CPU
> >>>> 
> >>>> Il 09/12/2013 19:37, Michal Skrivanek ha scritto:
> >>>>> 
> >>>>> 
> >>>>>> On 09 Dec 2013, at 18:58, Oved Ourfalli <ovedo at redhat.com> wrote:
> >>>>>> 
> >>>>>> 
> >>>>>> 
> >>>>>> ----- Original Message -----
> >>>>>>> From: "Michal Skrivanek" <michal.skrivanek at redhat.com>
> >>>>>>> To: "Sandro Bonazzola" <sbonazzo at redhat.com>, "Roy Golan"
> >>>>>>> <rgolan at redhat.com>
> >>>>>>> Cc: "engine-devel" <engine-devel at ovirt.org>
> >>>>>>> Sent: Monday, December 9, 2013 5:50:49 PM
> >>>>>>> Subject: Re: [Engine-devel] Setting cluster CPU
> >>>>>>> 
> >>>>>>> 
> >>>>>>>> On Dec 9, 2013, at 16:01 , Sandro Bonazzola <sbonazzo at redhat.com>
> >>>>>>>> wrote:
> >>>>>>>> 
> >>>>>>>> Hi,
> >>>>>>>> I'm trying to set the cluster CPU type while adding the first host
> >>>>>>>> to
> >>>>>>>> the
> >>>>>>>> Default cluster.
> >>>>>>>> 
> >>>>>>>> I know how to set the CPU type on a new cluster, since I'll do that
> >>>>>>>> in
> >>>>>>>> AIO
> >>>>>>>> plugin.
> >>>>>>>> But I'm not sure to understand how to set the CPU on an existing
> >>>>>>>> cluster.
> >>>>>>>> 
> >>>>>>>> Should it be enough to specify cpu arg while adding the host to the
> >>>>>>>> cluster?
> >>>>>>>> (before adding an host, cpu is None on the cluster)
> >>>>>>>> Because I'm trying to do that without success (obtaining a
> >>>>>>>> sandybridge
> >>>>>>>> cluster while specifying westmere cpu).
> >>>>>>> 
> >>>>>>> The CPU should be set from the first host if None. That is needed for
> >>>>>>> the
> >>>>>>> PPC
> >>>>>>> support. Roy, we talked about it recently, where are we with this
> >>>>>>> patch.
> >>>>>> 
> >>>>>> We already support modifying the CPU level of an existing cluster. If
> >>>>>> changing it to a higher level then we just change it.
> >>>>>> If changing it to a lower level, and there are running VMs on the
> >>>>>> cluster,
> >>>>>> then we warn the user that some VMs might not be migrate-able, as we
> >>>>>> added a scheduling filter to filter out hosts with improper CPU level.
> >>>>>> 
> >>>>>> Unless I'm missing something, that covers the use-case, isn't it?
> >>>>> 
> >>>>> Not sure. I thought this is None to something, where it should work
> >>>>> automatically without specifying anything. Just add an operational host
> >>>> 
> >>>> Well, here the issue is that while deploying hosted-engine VM, I'm on a
> >>>> SandyBridge host, with 1 VM running on it (the hosted engine VM).
> >>>> That VM has been created with CPU model Westmere to be able to migrate
> >>>> it
> >>>> to
> >>>> other hosts Westmere compatible.
> >>>> But the Default cluster is automatically set to SandyBridge when I add
> >>>> the
> >> 
> >> because it's created with None in the first place, and then set by the
> >> first
> >> host. If you'd create it with Westmere initially the joining host would
> >> not
> >> change it
> >> IMHO the setting should be done during the installation not via calling
> >> SDK
> >> on already created empty cluster but directly in the db when the db is
> >> deployed. Unless I'm missing the sequence of deployment.
> >> 
> > 
> > The hosted engine setup doesn't access the DB, so no reason to access it if
> > it is possible to do that via the SDK.
> > Didn't test that, but see no reason for it not to work.
> > 
> >>>> host also if I specify Westmere as CPU family in Host parameter.
> >>>> We may be able to set manually the CPU level later somehow, but since
> >>>> we've
> >>>> already asked the user about the CPU level I think we should avoid to
> >>>> ask
> >>>> the user to change it again later. See Bug 1034821 - Hosted-setup asks
> >>>> for
> >>>> CPU type but it doesn't set cluster to that CPU Level
> >>>> 
> >>> 
> >>> You can set the CPU level through the SDK, after you add the host (didn't
> >>> check that, but see no reason it won't work).
> >> 
> >> why so late in the process?
> >> 
> > 
> > why does it matter? The setup is still running, so, imo, the order is less
> > relevant, as long as the result is okay.
> 
> 
> depends. if hosted engine is part of the installation, it should do the
> modifications during installation the same way as anything else, forcefully,
> and not depend on working sdk or any other precondition
> if it is something you are/should be able to deploy over an existing setup
> it's better via sdk...
> 

Well... it is somewhere in between.
One of the steps in the hosted engine setup is to start a VM in which the user needs to install the engine.
So, adding the host is done via the SDK after the engine installation is completed.
That's why I thought it would be best to change the CPU level also after the engine installation is complete, and not during it.
In addition, it will probably also help covering the use-case of migrating an existing engine to a hosted engine environment (although I'm not familiar enough with the current proposed solution for this use-case).

> >>> 
> >>>> 
> >>>>> 
> >>>>>> 
> >>>>>>> Thanks,
> >>>>>>> michal
> >>>>>>> 
> >>>>>>>> 
> >>>>>>>> Michael, can you take a look at http://gerrit.ovirt.org/22129 and
> >>>>>>>> advise?
> >>>>>>>> 
> >>>>>>>> 
> >>>>>>>> --
> >>>>>>>> Sandro Bonazzola
> >>>>>>>> Better technology. Faster innovation. Powered by community
> >>>>>>>> collaboration.
> >>>>>>>> See how it works at redhat.com
> >>>>>>>> _______________________________________________
> >>>>>>>> Engine-devel mailing list
> >>>>>>>> Engine-devel at ovirt.org
> >>>>>>>> http://lists.ovirt.org/mailman/listinfo/engine-devel
> >>>>>>> 
> >>>>>>> _______________________________________________
> >>>>>>> Engine-devel mailing list
> >>>>>>> Engine-devel at ovirt.org
> >>>>>>> http://lists.ovirt.org/mailman/listinfo/engine-devel
> >>>>>>> 
> >>>> 
> >>>> 
> >>>> --
> >>>> Sandro Bonazzola
> >>>> Better technology. Faster innovation. Powered by community
> >>>> collaboration.
> >>>> See how it works at redhat.com
> >>>> _______________________________________________
> >>>> Engine-devel mailing list
> >>>> Engine-devel at ovirt.org
> >>>> http://lists.ovirt.org/mailman/listinfo/engine-devel
> >>>> 
> >> 
> >> 
> 
>