[placement][ptg] Allocation Partitioning

Chris Dent cdent+os at anticdent.org
Tue Apr 9 14:02:43 UTC 2019


On Tue, 9 Apr 2019, Jay Pipes wrote:
> On 04/08/2019 10:25 AM, Chris Dent wrote:

First, I'm trying to integrate several different mental models here,
which is probably why my terminology is a bit confused. There are
similar but not concurrent models from Dan, Jay, Mel, and Matt (that
I can recall) that we'll want to synchronized before we get too much
further on this.

> This is more "consumer type" than anything else. In order to satisfy usage 
> requests for certain classes of quota (really, just "num instances"), we need 
> to know which consumers in the consumers table are "Nova instances" and which 
> are not.

This is one of the mental models: Identify a consumer as having a type: "this
is a nova (any nova) instance". "consumer type", perhaps.

That's slightly different from another one of the mental models
which is: Identify a consumer as having a source: "this is from
service X (which happens to be a nova)". "consumer source", perhaps.

In the latter, at least some comments have involved there being
multiples services (of the same _type_) in the same OpenStack. I
don't know that this is a thing, yet, but it presumed to be
something that is possible, so not something we want to prevent in
the data model.

>> Of course it's important to also ask "should we distinguish?". If
>> there's a concept of unified limits does it matter whether a VCPU is
>> consume by _this_ nova or something else if they are consumed by the
>> same user?
>
> So this is referring to resource provider partition (source partition), not 
> consumer type. For the problem of detecting whether an instance is in *this* 
> Nova or another Nova deployment that uses the same placement service, we need 
> a source partition identifier in the resource_providers table.

That's not what I was trying to get at with my comment. What I was
wonder was:

If there exists a quota for VCPU does it matter how those VCPU are
being consumed in the entire quota domain? Does it matter if the
consumption is via nova or some other compute provisioning tool?

I'll try to address the multiple mental models for resource provider
partitioning in the other thread. Identify and resolving the
differences in mental models prior to the PTG is one of the main
reasons for having these threads, so huge success so far.

-- 
Chris Dent                       ٩◔̯◔۶           https://anticdent.org/
freenode: cdent                                         tw: @anticdent


More information about the openstack-discuss mailing list