----- Original Message ----- > From: "Adam Lawson" <alaw...@aqorn.com> > To: "Silence Dogood" <m...@nycresistor.com> > > Mathieu, > > Blame it on my scattered brain but I'm now curious. How would this be > approached practically speaking? I.e. how would ram_weight_multiplier > enable the scenario I mentioned in my earliest post ? > > //adam
It's specific to the scenario in Silence's post, which Mathiew was replying to directly. -Steve > > *Adam Lawson* > > On Thu, Mar 3, 2016 at 10:43 AM, Silence Dogood <m...@nycresistor.com> > wrote: > > > cool! > > > > On Thu, Mar 3, 2016 at 1:39 PM, Mathieu Gagné <mga...@internap.com> wrote: > > > >> On 2016-03-03 12:50 PM, Silence Dogood wrote: > >> > We did some early affinity work and discovered some interesting problems > >> > with affinity and scheduling. =/ by default openstack used to ( may > >> > still ) deploy nodes across hosts evenly. > >> > > >> > Personally, I think this is a bad approach. Most cloud providers stack > >> > across a couple racks at a time filling them then moving to the next. > >> > This allows older equipment to age out instances more easily for removal > >> > / replacement. > >> > > >> > The problem then is, if you have super large capacity instances they can > >> > never be deployed once you've got enough tiny instances deployed across > >> > the environment. So now you are fighting with the scheduler to ensure > >> > you have deployment targets for specific instance types ( not very > >> > elastic / ephemeral ). goes back to the wave scheduling model being > >> > superior. > >> > > >> > Anyways we had the braindead idea of locking whole physical nodes out > >> > from the scheduler for a super ( full node ) instance type. And I > >> > suppose you could do this with AZs or regions if you really needed to. > >> > But, it's not a great approach. > >> > > >> > I would say that you almost need a wave style scheduler to do this sort > >> > of affinity work. > >> > > >> > >> You can already do it with the RAMWeigher using the > >> ram_weight_multiplier config: > >> > >> Multiplier used for weighing ram. Negative > >> numbers mean to stack vs spread. > >> > >> Default is 1.0 which means spread. > >> > >> -- > >> Mathieu _______________________________________________ OpenStack-operators mailing list OpenStack-operators@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators