> -----Original Message----- > From: Jay Pipes [mailto:jaypi...@gmail.com] > Sent: 09 June 2014 19:03 > To: openstack-dev@lists.openstack.org > Subject: Re: [openstack-dev] [nova] Proposal: Move CPU and memory > allocation ratio out of scheduler > > On 06/09/2014 12:32 PM, Chris Friesen wrote: > > On 06/09/2014 07:59 AM, Jay Pipes wrote: > >> On 06/06/2014 08:07 AM, Murray, Paul (HP Cloud) wrote: > >>> Forcing an instance to a specific host is very useful for the > >>> operator - it fulfills a valid use case for monitoring and testing > >>> purposes. > >> > >> Pray tell, what is that valid use case? > > > > I find it useful for setting up specific testcases when trying to > > validate things....put *this* instance on *this* host, put *those* > > instances on *those* hosts, now pull the power plug on *this* host...etc. > > So, violating the main design tenet of cloud computing: though shalt not care > what physical machine your virtual machine lives on. :) > > > I wouldn't expect the typical openstack end-user to need it though. > > Me either :)
But the full set of system capabilities isn't only about things that an end-user needs - there are also admin features we need to include. Another use case for this is to place a "probe" instance on specific hosts to help monitor specific aspects of the system performance from a VM perspective. > > I will point out, though, that it is indeed possible to achieve the same use > case using host aggregates that would not break the main design tenet of > cloud computing... just make two host aggregates, one for each compute > node involved in your testing, and then simply supply scheduler hints that > would only match one aggregate or the other. > Even I wouldn't argue that aggregates are a great solution here ;-) Not only does having single node aggregates for every host you want to force to seem a tad overkill, the logic for this "admin" feature includes by-passing the normal scheduler filters, > Best, > -jay > > > _______________________________________________ > OpenStack-dev mailing list > OpenStack-dev@lists.openstack.org > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev