Open Stack

> -----Message d'origine-----
> De : Jay Pipes [mailto:jaypipes at gmail.com]
> Envoyé : mardi 8 avril 2014 15:25
> À : openstack-dev at lists.openstack.org
> Objet : Re: [openstack-dev] [Nova] Hosts within two Availability Zones : 
> possible
> or not ?
>
> On Tue, 2014-04-08 at 10:49 +0000, Day, Phil wrote:
> > On a large cloud you’re protect against this to some extent if the
> > number of servers is >> number of instances in the quota.
> >
> > However it does feel that there are a couple of things missing to
> > really provide some better protection:
> >
> > -         A quota value on the maximum size of a server group
> > -         A policy setting so that the ability to use service-groups
> > can be controlled on a per project basis
>
> Alternately, we could just have the affinity filters serve as weighting 
> filters
> instead of returning NoValidHosts.
>
> That way, a request containing an affinity hint would cause the scheduler 
> to
> prefer placing the new VM near (or not-near) other instances in the server
> group, but if no hosts exist that meet that criteria, the filter simply 
> finds a host
> with the most (or fewest, in case of anti-affinity) instances that meet 
> the affinity
> criteria.
>
> Best,
> -jay
>

The filters guarantee the desired effect, while the weighers just give the 
preference. Thus it makes sense to have AntiAffinity as a filter. Otherwise 
what is it good for if users do not know if their anti-affiniti-ed VMs are 
hosted in different hosts. I prefer the idea of anti-affinity quota. May 
propose that.

> > From: Khanh-Toan Tran [mailto:khanh-toan.tran at cloudwatt.com]
> > Sent: 08 April 2014 11:32
> > To: OpenStack Development Mailing List (not for usage questions)
> > Subject: Re: [openstack-dev] [Nova] Hosts within two Availability
> > Zones : possible or not ?
> >
> > “Abusive usage” : If user can request anti-affinity VMs, then why
> > doesn’t he uses that? This will result in user constantly requesting
> > all his VMs being in the same anti-affinity group. This makes
> > scheduler choose one physical host per VM. This will quickly flood the
> > infrastructure and mess up with the objective of admin (e.g.
> > Consolidation that regroup VM instead of spreading, spared hosts,
> > etc) ; at some time it will be reported back that there is no host
> > available, which appears as a bad experience for user.
> >
> >
> >
> >
> >
> > De : Ian Wells [mailto:ijw.ubuntu at cack.org.uk] Envoyé : mardi 8 avril
> > 2014 01:02 À : OpenStack Development Mailing List (not for usage
> > questions) Objet : Re: [openstack-dev] [Nova] Hosts within two
> > Availability Zones : possible or not ?
> >
> >
> >
> >
> > On 3 April 2014 08:21, Khanh-Toan Tran <khanh-toan.tran at cloudwatt.com>
> > wrote:
> >
> >         Otherwise we cannot provide redundancy to client except using
> >         Region which
> >         is dedicated infrastructure and networked separated and
> >         anti-affinity
> >         filter which IMO is not pragmatic as it has tendency of
> >         abusive usage.
> >
> >
> >
> >
> >
> > I'm sorry, could you explain what you mean here by 'abusive usage'?
> >
> >
> >
> > --
> >
> >
> > Ian.
> >
> >
> > _______________________________________________
> > OpenStack-dev mailing list
> > OpenStack-dev at lists.openstack.org
> > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>
>
>
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