[placement][ptg] Allocation Partitioning
On Tue, 16 Apr 2019 12:26:37 -0700, Dan Smith <dms at danplanet.com> wrote:
>> When a /usages query is made, the consumer type could be optionally
>> expressed, limiting results. Are multiple types something that needs
>> to be expressed in one query? Not yet discussed.
> I expect that Nova's quota stuff will want to be able to express
> multiples, FWIW. However, I think I can say for sure that the usage
> result will be the most useful for quota behavior if it returns usages
> grouped by type (whether or not a subset of types were in a filter
Yes, would be helpful to be able to get multiple consumer types in a
single query. I agree that we would need to be able to sort through the
different consumer types on the response side. For example, we'll want
to be able to count quota usage as max('instance' usage, 'migration'
usage) during a resize. And if a multiple consumer types filtered query
returned a roll-up of all usages without grouping by consumer type, we
would not be able to do the max thing we want to do without multiple
separate queries to placement. Note that this reminds me that today we
have to do two separate queries to placement, one filtered by project_id
and one filtered by project_id and user_id in order to roll-up usage for
a project and usage for a project user, for similar reasons.