| Posted | Nick | Remark | |
|---|---|---|---|
| #openstack-nova - 2025-02-25 | |||
| 16:41:29 | gibi | I think the next step there is to have PTG topic proposed for this | |
| 16:42:12 | sean-k-mooney | hertrste our main concerns would be likely testing, and building out a minimal supportrable feature set | |
| 16:42:36 | bauzas | yeah, looks to me a good PTG session | |
| 16:42:39 | sean-k-mooney | that would invovle defining a spec (if the propsal to add a new driver was green lit) | |
| 16:42:42 | bauzas | hertrste: can you attend it ? | |
| 16:42:44 | dansmith | I'd also be interested in knowing how widely it is used/deployed | |
| 16:42:44 | sean-k-mooney | to descibe the expecations | |
| 16:43:05 | dansmith | and also, why it's not just a libvirt driver :) | |
| 16:43:50 | sean-k-mooney | well i dont neesislay think we shoudl say all linux hyperviors shoudl be behind libvirt | |
| 16:43:55 | hertrste | I can very much attend a PTG. What would I need to prepare for that? When would that meeting take place? | |
| 16:43:57 | sean-k-mooney | it has its pros and cons | |
| 16:44:43 | dansmith | sean-k-mooney: no, doesn't have to be, but there's a lot of stuff to re-implement in nova if it's not, and so I'd expect there to be a good reason for it | |
| 16:44:50 | gibi | hertrste: https://openinfra.org/ptg/ | |
| 16:44:54 | bauzas | hertrste: see the above discussion about PTG | |
| 16:45:32 | Uggla | hertrste, Apr 7-11 | |
| 16:45:38 | sean-k-mooney | hertrste: i think the main things to prepare is an elevator pitch explaining why an operator may want ot use this | |
| 16:45:53 | sean-k-mooney | wwhat usecases and target workloads woudl it enable | |
| 16:46:02 | tpressure | libvirt has a poor hypervisor abstraction. If we would go the libvirt route, we would effectively have to maintain two components instead of only one. You cannot simply map qemu calls to cloud hypervisor | |
| 16:46:05 | dansmith | sean-k-mooney: especially since it appearently already exist: https://libvirt.org/drvch.html | |
| 16:46:19 | sean-k-mooney | and beyond that how you plan to test and develop supproted for it on an ongoing basis | |
| 16:46:58 | sean-k-mooney | tpressure: well we dont generate qemu calls today | |
| 16:47:10 | sean-k-mooney | nova generate a semi hypervior indepent xml | |
| 16:47:31 | sean-k-mooney | we "supprot" libvirt with lxc, qemu and i think openvz | |
| 16:47:47 | sean-k-mooney | althoug everything excpt for qemu is basiclly not tested or maintaiend anymore | |
| 16:48:19 | sean-k-mooney | tpressure: hertrste based on https://libvirt.org/drvch.html provied by dan there si already some supprot for cloud-hypervior in libvirt | |
| 16:48:31 | hertrste | yeah we know of that support | |
| 16:48:36 | sean-k-mooney | so the question woudl be what does a full virt driver provide that cant be done vai that | |
| 16:49:04 | dansmith | and more than that, why would it be worth maintaining that *and* a separate full nova driver | |
| 16:49:29 | dansmith | like, what will never be possible via libvirt that would be if we have a whole separate implementation in nova | |
| 16:49:31 | hertrste | we decided not to use it because we felt the overhead of dealing with the existing 14k LoC for the libvirt backend in Nova was not worth. at least for a proof of concept | |
| 16:49:53 | dansmith | because libvirt brings all kinds of things like network and storage abstraction that would have to be written from scratch in a nova driver | |
| 16:50:03 | hertrste | Further, libvirt only has very basic support for cloud hypervisor. so we basically would need to add features in 2 complex code bases | |
| 16:50:31 | sean-k-mooney | the main concern i would have iwth the current poc | |
| 16:50:41 | sean-k-mooney | is its directly invoking a command line client correct | |
| 16:50:52 | dansmith | hertrste: that's only true if you're talking about a feature that isn't supported at all by libvirt, which is honestly going to be a hard sell in nova anyway | |
| 16:51:01 | sean-k-mooney | which means you are commiting to providign a forward compatiable stable cli fro nova to use | |
| 16:51:40 | bauzas | folks, because we have another item to discuss, can we stop here ? | |
| 16:51:46 | dansmith | sean-k-mooney: and hopefully there is some way to not kill those instances when nova restarts.. I hope it doesn't make nova responsible for being the init system for those binaries... | |
| 16:51:59 | sean-k-mooney | sure we can move on | |
| 16:52:05 | dansmith | bauzas: yes, I have to run anyway.. but a preview of my concerns for PTG :) | |
| 16:52:06 | sean-k-mooney | dansmith: ack | |
| 16:52:19 | hertrste | thanks for the feedback | |
| 16:52:30 | bauzas | hertrste: ping me if you have any questions about the PTG, I'll try to answer your concerns | |
| 16:52:40 | bauzas | moving on then | |
| 16:52:50 | bauzas | (mzhang741) Add Burst Length Support to Cinder QoS | |
| 16:52:58 | bauzas | is mzhang741 here ? | |
| 16:53:05 | MengyangZhang[m] | yes | |
| 16:53:08 | bauzas | https://review.opendev.org/c/openstack/nova-specs/+/932653 | |
| 16:53:42 | bauzas | seems to me a design question | |
| 16:53:53 | bauzas | could we just do this in the gerrit change review ? | |
| 16:54:11 | bauzas | do we need a quorum consensus ? | |
| 16:55:58 | MengyangZhang[m] | besides that min version check question, also need review and approval of the spec to move forward | |
| 16:56:29 | bauzas | MengyangZhang[m]: that's our usual review cycle | |
| 16:56:44 | bauzas | but for the moment, even 2025.2 work hasn't started | |
| 16:56:59 | bauzas | so please understand that people have other priorities for now | |
| 16:57:34 | bauzas | MengyangZhang[m]: the best if you want is to have a cross-project discussion with the cinder folks at the PTG | |
| 16:57:46 | sean-k-mooney | bauzas: context for this | |
| 16:57:50 | bauzas | that would I guess answer most of the design questions, and it would be quick | |
| 16:58:01 | MengyangZhang[m] | understood, meanwhile can I have some clarity on that design question? I may shift my focus to other projects in my company and won't be able to follow this until q2 | |
| 16:58:06 | sean-k-mooney | i was orginally asking that we have a min version ceck to know that the compute node can supprot the new frontend qos option | |
| 16:58:24 | sean-k-mooney | it turns out that cinder allows you to update the qos on a volume type | |
| 16:58:28 | bauzas | sean-k-mooney: that's the usual upgrade pattern yeah | |
| 16:58:37 | sean-k-mooney | and it will take effect to all volumes of that type | |
| 16:58:42 | sean-k-mooney | on the next move op | |
| 16:58:50 | sean-k-mooney | or when we next update the attachment | |
| 16:59:06 | bauzas | so even old computes would see it ? | |
| 16:59:07 | sean-k-mooney | so cinder is not caching it liek we do with the falvor/image properties when the volume is created | |
| 16:59:10 | sean-k-mooney | yep | |
| 16:59:21 | sean-k-mooney | so this is a pre exisitng upgrade problem | |
| 16:59:24 | bauzas | that's an harder upgrade pattern to solve | |
| 16:59:30 | bauzas | yeah, sounds | |
| 16:59:43 | sean-k-mooney | so i dont think we can actully really protect agaisnt this in nova | |
| 16:59:43 | bauzas | like, someone has to do a pre-upgrade flight | |
| 17:00:04 | bauzas | we could say 'unsupported until all your computes are upgraded' | |
| 17:00:06 | sean-k-mooney | anyway we shoudl dicuss more with the cinder folks | |
| 17:00:32 | sean-k-mooney | but we cant just enforce "not supported until all upgraded" in our code just in docs | |
| 17:00:33 | bauzas | is there any API impact? tbh I haven't reviewed the spec | |
| 17:00:39 | bauzas | hah | |
| 17:01:00 | bauzas | sounds to me then a perfect cinder-nova PTG discussion | |
| 17:01:13 | bauzas | MengyangZhang[m]: could you join the PTG ? | |
| 17:01:29 | bauzas | anyway, we're on time | |
| 17:01:35 | bauzas | thanks all | |
| 17:01:39 | bauzas | #endmeeting | |
| 17:01:39 | opendevmeet | Meeting ended Tue Feb 25 17:01:39 2025 UTC. Information about MeetBot at http://wiki.debian.org/MeetBot . (v 0.1.4) | |
| 17:01:39 | opendevmeet | Minutes: https://meetings.opendev.org/meetings/nova/2025/nova.2025-02-25-16.00.html | |
| 17:01:39 | opendevmeet | Minutes (text): https://meetings.opendev.org/meetings/nova/2025/nova.2025-02-25-16.00.txt | |
| 17:01:39 | opendevmeet | Log: https://meetings.opendev.org/meetings/nova/2025/nova.2025-02-25-16.00.log.html | |
| 17:01:45 | MengyangZhang[m] | sure, do i need to register for the event? You mean the one from April 7-11, right? Let me know what I need to do | |
| 17:02:04 | MengyangZhang[m] | sorry would be my first time joining | |
| 17:02:40 | sean-k-mooney | bauzas: no api impact on our side or cinders becuase they dont version this part of the api | |
| 17:03:17 | sean-k-mooney | althogh that coudl depend on the ptg dicussion | |
| 17:03:25 | bauzas | sean-k-mooney: I definitely need to review the spec then | |
| 17:03:34 | sean-k-mooney | one topic MengyangZhang[m] was interested in was a way to refesh the qos on a volume live | |
| 17:03:37 | fwiesel | Thanks everyone | |
| 17:03:40 | sean-k-mooney | that woul likely need a new instance action | |
| 17:03:48 | bauzas | wow | |
| 17:03:54 | sean-k-mooney | but i dont think that is in the spec | |
| 17:04:04 | bauzas | 'taint my instance' | |
| 17:04:06 | sean-k-mooney | bauzas: libvirt supprot updatign them | |
| 17:04:12 | sean-k-mooney | we just dont | |