[placement][ptg] Aggregate on root spans whole tree policy:

Ed Leafe ed at leafe.com
Mon Apr 22 13:00:54 UTC 2019

On Apr 21, 2019, at 5:20 PM, Jay Pipes <jaypipes at gmail.com> wrote:
> On 04/09/2019 09:00 AM, Chris Dent wrote:
>> From the etherpad [1]:
>> * Last PTG for Stein, we decided the following policies and have done so in Stein
>>     A) Aggregate on root spans whole tree for ``members_of=``
>>        requests in 'GET /allocation_candidates'
>>     B) This spanning policy doesn't apply to granular requests
>>        ``members_of<N>=`` or to requests in 'GET /resource_providers'
>>     C) This change is a bug fix without microversion
>>   However, I now feel the policy B is weird. Consider a case where
>>   only granular requests are used in the request. If operator puts
>>   aggA on root, aggA applies the child or not depends on cases how
>>   you created the request. That's very difficult for operators to
>>   debug...
>> This is from Tetsuro, so perhaps he can add some additional info,
>> but basically I think what's being requested here is some discussion
>> on whether changing B is warranted.
> We have a similar issue with traits.
> I actually think there should be a single "apply membership or traits using self-and-children" policy. I've been unable to think of any use case that would *not* be serviced by this policy.

Not only that, but I can’t imagine a scenario where we would want membership of one RP but forbid membership by a child. That would be… strange.

-- Ed Leafe

More information about the openstack-discuss mailing list