openstack team mailing list archive

[Matthew Sherborne <matt.sherborne@xxxxxxxxxxxxx>]

Hi Openstackers,

Just wondering, is there any reason flavors are not limited to just
create-time?  Meaning, use it to create a new instance and then copy all of
the flavor data into the new instance's data. This breaks the relationship
between the instance and the flavor, allow each to be changed independently
- or even deleted.  Doing this would mean you wouldn't need to add a
"disabled" flag at all - just delete the flavor if you don't want anyone to
use it.   This would also allow for an easier modification of existing
instances - just modify the instance's property that needs to change w/o
creating a whole new flavor (avoids the proliferation of flavors too).

That's an idea we had for a future version. It does seem to make the most
sense. If no-one can think of a reason not to have it, it might be worth
just going straight there, or at least researching the possibility.

Any objections or heads up OS community ?

The idea would be, instance types (or flavors, or sizes) are basically just
listed there for creating and re-sizing to. Once an instance is built with
that type, all the instance type data is copied to the instance record
itself.

I can't think of any insurmountable reason's not have it this way.

The main reason to have instance flavors uncoupled from the flavor menu is
that it makes the most sense, and makes a bunch of other tasks become
basically zero work:

   - Phasing out a flavor
   - Having an instance running on a deleted flavor still:
      - be able to rebuild
      - migrate from a failed host and keep it's flavor
      - show user's it's flavor name when queried for it

Some things that it could make harder though; but not impossible:

   - Upgrading a bunch of instances to a new size/flavor.
   - Finding a bunch of instances with a certain flavor
   - It could lead to a large number of flavors over time, but that'd be
   more due to admin's not phasing out flavor's properly.

What say ye openstackers ?

Kind Regards,
Matthew Sherborne

On Sat, Jun 2, 2012 at 2:54 AM, Doug Davis <dug@xxxxxxxxxx> wrote:

>
> Just wondering, is there any reason flavors are not limited to just
> create-time?  Meaning, use it to create a new instance and then copy all of
> the flavor data into the new instance's data. This breaks the relationship
> between the instance and the flavor, allow each to be changed independently
> - or even deleted.  Doing this would mean you wouldn't need to add a
> "disabled" flag at all - just delete the flavor if you don't want anyone to
> use it.   This would also allow for an easier modification of existing
> instances - just modify the instance's property that needs to change w/o
> creating a whole new flavor (avoids the proliferation of flavors too).
>
> thanks
> -Doug
> ______________________________________________________
> STSM |  Standards Architect  |  IBM Software Group
> (919) 254-6905  |  IBM 444-6905  |  dug@xxxxxxxxxx
> The more I'm around some people, the more I like my dog.
>
>
>  *Matthew Sherborne <matt.sherborne@xxxxxxxxxxxxx>*
> Sent by: openstack-bounces+dug=us.ibm.com@xxxxxxxxxxxxxxxxxxx
>
> 06/01/2012 10:41 AM
>   To
> openstack@xxxxxxxxxxxxxxxxxxx
> cc
>   Subject
> [Openstack] hidden / phasing out instance_types/flavors
>
>
>
>
> Hi Openstack community,
>
> We recently uploaded this change: *https://review.openstack.org/#/c/8007/*<https://review.openstack.org/#/c/8007/>
>
> It adds a 'disabled' field to the 'instance_type' or 'flavor' concept.
>
> The usage scenario we had in mind was to phase out a flavor that's already
> in use; people shouldn't be able to build new instances from that flavor,
> nor should customers see it in the list of available flavors. But when they
> view an existing instance with that flavor type, they should still be able
> to see the name of it at least. But should you change your mind later and
> wish to re-enable it, it's easy to just flip the flag.
>
> We'd appreciate feedback on the added field and the use of the namespace
> in the core code. (Line 56 here: *
> https://review.openstack.org/#/c/8007/1/nova/api/openstack/compute/views/flavors.py
> *<https://review.openstack.org/#/c/8007/1/nova/api/openstack/compute/views/flavors.py>
>  )
>
> The reasoning behind this is:
>  * If we did it as an extension, it would greatly complicate the code. The
> code is much simpler being right in the core code.
>  * We can't just add a field to the API quickly, so we need to use the
> namespace.
>  * The hope is that eventually it would be accepted into the  main API
> anyway, then the coding would be just removing the namespace.
>
> Many thanks in for reading. All feedback appreciated.
>
> Kind Regards,
> Matthew Sherborne_______________________________________________
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