Open Stack

On Fri, 2014-04-04 at 20:39 -0500, Narayan Desai wrote:
> This doesn't particularly hit our main quota issue. IMO templates
> could easily be implemented with a script. Also, the more I think
> about it, they probably should be implemented that way, since this
> kind of policy often gets overly complex when you try to implement a
> general solution, and the script solution is just fine for us.
> 
> If you're interested in quotas, we have a completely different problem
> with quotas that is a real showstopper for us. We have a really large
> dynamic range in resource quantities for our different instance types.
> (for example, we have 3 orders of magnitudes in the range of memory
> configurations). This makes quotas pretty useless for us as they are
> currently implemented, since you can't represent limits for these
> different kinds of resources in the same quota.

Why can't you? The resource is the memory, CPU, and disk used, not the
instance type.

Honestly, I think that this is a user-interface thing, not a quota
management thing. In other words, have the quota-management UI show some
translation help-text. For the user, it would be something like "you
have room for X m2.xlarge instances left". For an admin it would be
something like "this quota allocation represents X m2.xlarge instances".

>  Something like per-instance-type quotas would at least allow us to
> restrict users to a fixed number of instances of a given type,
> bypassing the current quota mechanism.

The only problem with this is that what happens if an instance type's
underlying resource allocation changes? Quotas and reservations
generally need to be on the actual resources that are consumed, not on
an abstract representation of those resources like an instance type, due
to the fact that the abstract representation can changes over time.

My idea about the UI above works nicely with the idea of changeable
instance types. The UI can do simple real-time calculations about what a
quota allocation represents in terms of the actual resources used by an
instance type.

Best,
-jay