On 16/10/2024 19:49, Dmitriy Rabotyagov wrote:
>
> Hey,
>
> Somebody may correct me, but to the best of my knowledge this
> functionality is currently not implemented in Nova.
>
it was proposed, discused for a few release and ultimatly rejected.


https://blueprints.launchpad.net/nova/+spec/preemptible-instances
https://review.opendev.org/c/openstack/nova-specs/+/438640
https://review.opendev.org/c/openstack/nova/+/547450


the most recen tspec that was aproved for this was

https://specs.openstack.org/openstack/nova-specs/specs/train/approved/introduce-pending-vm-state.html

and out of tree protype was developed

https://gitlab.cern.ch/ttsiouts/ReaperServicePrototype

but it was never compelted.

after that did not pan out it moved to balzar

https://specs.openstack.org/openstack/blazar-specs/specs/ussuri/blazar-preemptible-instances.html


and again it never completed to my knowladge

> I can assume there could be some custom scheduler filters/weighers in
> the wild (not 100% sure this can be done solely through scheduling
> though), but I personally haven't seen one so far.
> Though I was asked a couple of times during last year about exactly
> the same thing. So you're totally not alone looking for a solution for
> spot instances.
>
>

it is a potential usescase that could be supproted but the logic for
doign the reaping/premetion is non trvial to do correctly.

one approch we have rejected in the past is havign nova's sechuler call
out to another service if we cant find a host

or activly reaping premtiable instnace in that case.


> On Wed, Oct 16, 2024, 14:09 Mia <mikasa.ack1618@gmail.com> wrote:
>
>     Hello everyone,
>
>     I am working on a project in the OpenStack environment. More
>     precisely, I am looking into the implementation of spot instances
>     as a cost optimization strategy and better resource utilization.
>
>     If any community members could share their experiences and
>     insights related to the following areas, it would be greatly
>     appreciated.
>     Implementation Strategies: How did you go about implementing spot
>     instances in your cluster?
>     Challenges Faced: Mention some of the challenges or limitations.
>     Best Practices: Do you have any recommendations or best practices
>     that you would like to suggest for seamless deployment?
>
>     Thank you very much for your time and support.
>