Earlier  
Later
New Search
Posted Nick Remark
#openstack-nova - 2025-02-13
15:34:48 sean-k-mooney i think there is merrit in having the behavior/syntax mirror that of the exisitng metric weigher
15:34:59 sean-k-mooney mainly just for consitency
15:35:06 bauzas okay I can take a look
15:36:25 sean-k-mooney i dont know if that woudl satisfy all open concerns or not but that was the tldr, get the simple version workign and passing then follow patch to extend and discuss later if we finally want to implement supprot for prefered traits
15:36:47 bauzas gibi: reading your comments, you know that we only compare the host properties against the exact image requested properties, right ?
15:37:36 bauzas I originally tried to compare all props as equal, but I eventually considered only the calculation of how many requested props were present on the host
15:41:39 dansmith I think gibi's point is that many irrrelevant props may be requested that dilute the scoring
15:41:40 gibi I'm not sure I see the consequences of it as I don't know what host properties means in this context
15:41:47 gibi dansmith: yes
15:42:21 gibi preferred traits in image metadata implemented as a weigher seems interesting and promising but haven't spent the time to think it through
15:42:42 sean-k-mooney gibi: its something i have wanted since before we actully had required traits
15:42:47 gibi as that would mean each image defines what property it cares about
15:43:09 sean-k-mooney if we supported prefered traits i woudl want to supprot it for both flavor and image ideally
15:43:42 sean-k-mooney but same overall impleation just way the host based on teh prefernce using the provider summaries
15:44:16 bauzas gibi: I need to validate your example in https://review.opendev.org/c/openstack/nova/+/940642/comment/932beb0e_c4933c32/
15:46:13 bauzas gibi: because while I agree with the fact that VM1 will be on host1 and VM2 on host2, I need to calculate the weight for VM3
15:46:50 dansmith to make it fully automatic you need to automatically export the trait when an instance is booted on a host, so perhaps some conf knob to expose traits of a thing automatically? l
15:46:59 dansmith auto_expose_image_props = os_type
15:47:07 gibi bauzas: my understanding is more matching properties means higher weights
15:47:26 bauzas you're right indeed, I see the problem now
15:47:43 gibi dansmith: good point, a full dynamic approach needs dynamic traits
15:47:48 bauzas well, that's not really a problem, you're diluting your need into multiple pieces
15:47:49 dansmith I again assert that for a cloudy workload that probably gets stronger with lots of boots of the same image
15:48:18 bauzas I assumed less fine-grained image properties
15:48:19 dansmith if you have tons of snowflake pet images then for sure it will be a very weak force
15:48:22 dansmith right
15:48:38 dansmith and I assumed this was a soft clumping optimization and not a hard packing mechanism
15:48:45 bauzas yup, KISS
15:48:52 dansmith because if you want the latter, it should use stronger guarantees
15:48:57 gibi dansmith: VMs from the same image attract each other I agree. So if we only have a single windows image then the solution works
15:49:20 dansmith gibi: or some small number of them that are probably going to be similar
15:49:25 bauzas we have a meeting in 20 mins
15:49:28 bauzas 10 mins*
15:49:42 bauzas but I think we need a design discussion indeed
15:50:00 bauzas so if you want, let's do that after the internal meeting, ie. 1700UTC
15:50:24 bauzas would 1700UTC work for the three of you ? sean-k-mooney gibi dansmith
15:50:34 dansmith I figure not gibi
15:50:40 dansmith but wfm
15:51:44 bauzas OK, I refreshed my brain on the metricsweigher
15:51:56 sean-k-mooney sure
15:52:13 bauzas fun fact, there was a note with my name, so I already walked that code
15:52:27 gibi dansmith: yeah this is a balancing act. if you have more windows images or if the windows images have a lot of other prop than os_type then you are losing the feature. Now the question is is this compromise acceptable for the customer requesting the feature. Telling them to limit the number of different windows VMs or limit the number of image props (it is already a lot by default from glance) might
15:52:29 bauzas but gosh my brain is so bad at remembering things
15:52:33 gibi be OK or might not. I leaning towards no. But we can probably ask :)
15:53:00 gibi bauzas: I can take a 30 min meeting after our internal call
15:53:11 bauzas gibi: sean-k-mooney's approach mimicing the metricsweigher seems a reasonable trade-off as a follow-up patch
15:53:38 dansmith gibi: yeah, all goes to how strongly you expect it to work. I expected weak optimization because it needs to be fully automatic
15:53:55 dansmith or intended to be fully automatic I mean
15:54:01 bauzas basically, it makes the weigh multiplier less easy to configure but that gives you a possibility to weigh per prop
15:54:14 sean-k-mooney for hard affinity we have the "isolating aggrates with placement" feature
15:54:22 dansmith I pretty much assume any weigher implementation is just trying to make better-than-random decisions, but not anything you'd bet on
15:54:49 dansmith bauzas: you mean my suggestion of a dict of properties and weights?
15:55:26 dansmith I think that gets closer to gibi's goal, but I also offered that suggestion along with a good example of why it's too simplistic
15:55:27 sean-k-mooney the weigher multipler is for seting the relitve weight between weighers when nomalising
15:55:50 sean-k-mooney the per property weight is internal
15:56:03 sean-k-mooney to how we calulate a weight for a given host before we normalise
15:56:13 sean-k-mooney so they have 2 distinct usecases
15:57:13 sean-k-mooney anyway shall we pick this up in an hour
15:58:51 bauzas yup, let's see ourselves in 1 hour
15:58:55 bauzas I'll ping back here
15:59:05 bauzas others can chime if they want
17:02:01 gibi need 2 minutes and I can join
17:02:32 bauzas okay, I'm starting a gmeet
17:03:52 bauzas https://meet.google.com/vye-tjns-bai <= for discussing about https://review.opendev.org/c/openstack/nova/+/940642/
17:42:13 sean-k-mooney bauzas: gibi dansmith melwitt on an unrelated note. neutron removed linuxbridge supports weeks ago
17:42:25 sean-k-mooney os-vif and nova have linux bridge jobs
17:42:45 sean-k-mooney the nova one only tirggers on specific files
17:43:17 sean-k-mooney tehre was a mailing list post about this a while ago but i just want to get poeopel opions on how to move forward
17:43:34 sean-k-mooney first ill put up a patch to drop hte job form nova's check pipeline
17:44:09 sean-k-mooney beyond that there is a patch to remove the job form os-vif but i think we should also remove the linux brindge os-vif plugin
17:44:43 sean-k-mooney os-vif's policy has always been we only have pluggins for in tree neutron backends
17:45:16 sean-k-mooney so question 1 is do i defer the plugin removal to 2025.2 or do it in 2025.1/epoxy
17:45:51 sean-k-mooney second question is there is linux bridge speciric code in nova. wehn shoudl we remove that?
17:46:07 sean-k-mooney my propsoal is to formally deprecate the linux bridge support in nova this cycle
17:46:18 sean-k-mooney and remove the linux brdige code in nova in 2025.2
17:47:22 sean-k-mooney you would only be able to user linux brdige in nvoa as part fo 2025.1 if you had an older neutron but since we never deprecated support you could argure that that is the best path forward
17:47:34 sean-k-mooney we coudl also just be more agressive and delete the code now
17:48:28 sean-k-mooney bauzas: gibi dansmith melwitt ^ we dont have to decied now but let me know what ye woudl perfer
17:49:14 dansmith idk, deprecate and lag on removal I guess
17:50:43 sean-k-mooney if we go with that approch ill change my review on https://review.opendev.org/c/openstack/os-vif/+/941567
17:58:57 sean-k-mooney ill prepare patches to do the formal dpercations and unblock ci this evening and we can review in the irc meeting on tusday. the non clint lib freeze is next week so we need to do an os-vif release wiht the deprecation but i that thats ok
18:36:05 opendevreview sean mooney proposed openstack/os-vif master: Deprecate linux bridge supprot https://review.opendev.org/c/openstack/os-vif/+/941585
18:36:06 opendevreview sean mooney proposed openstack/os-vif master: remove linux bridge plugin https://review.opendev.org/c/openstack/os-vif/+/941586
18:37:08 opendevreview sean mooney proposed openstack/os-vif master: Deprecate linux bridge plugin https://review.opendev.org/c/openstack/os-vif/+/941585
18:37:09 opendevreview sean mooney proposed openstack/os-vif master: remove linux bridge plugin https://review.opendev.org/c/openstack/os-vif/+/941586
19:02:27 bauzas sean-k-mooney: still there ?
19:03:38 bauzas sean-k-mooney: just a question, given the logic of the conf options for the metricsweigher sound reasonable to me, I wonder whether I should duplicate those options for my specific weigher or reuse those metrics options by adding a doc modification saying that the ImageMetaWeigher could also use them ?
19:04:15 sean-k-mooney yep
19:04:40 sean-k-mooney you need to duplicate them
19:04:40 bauzas yep about which alternative ? dup or reuse ?
19:04:44 sean-k-mooney yep im here
19:04:44 bauzas ok
19:05:27 bauzas OK then let's go for specifying them
19:05:31 bauzas thanks
19:06:01 sean-k-mooney the other reason they have to be seperated is
19:06:32 sean-k-mooney with the new weither if the new config option is not defied we effectivly weigh each option as 1
19:06:35 sean-k-mooney i.e. evenly
19:07:03 sean-k-mooney but when its defiend we woudl only apply the weigts to the specified values and ignore the rest
19:07:30 sean-k-mooney where as for the metric weigher the cofnig option is required for it to work
19:07:40 sean-k-mooney instead of being optional

Earlier   Later