Earlier  
Posted Nick Remark
#openstack-nova - 2018-08-30
14:12:19 bauzas if executed in separate workers, CONF.cpu_allocation_ratio wouldn't be defined for nova-scheduler
14:12:36 bauzas oh wait, sec
14:12:51 mriedem it doesn't need to be defined in config, we have a default
14:12:53 mriedem which is global
14:13:17 mriedem anyway, that doesn't really matter for this bug
14:13:28 mriedem the compute reports the inventory to placement and is reporting 0.0 allocation ratios
14:14:20 cdent mriedem: one thing that remains unclear for me (becuase apparently I can't read python code) is why the second inventory PUT (the one with the 0.0) is happening at all (and so soon)
14:18:03 bauzas mriedem: I think your working theory you stated in the bug comment is valid
14:18:22 bauzas I'm trying to wrap my head around on exactly when we pull the DB values
14:19:04 openstackgerrit Matt Riedemann proposed openstack/nova master: Revert "Update resources once in update_available_resource" https://review.openstack.org/598176
14:21:12 bauzas mriedem: I think we began having problems with https://github.com/openstack/nova/commit/7b95b4d60726b6c8d0e0fe939c408a91ada79e0c
14:21:36 bauzas I'm not saying it's all the bugs cause
14:21:57 bauzas just that it implicitly creates a dependency on us calling .save() after it
14:22:10 bauzas because if not, we would then have 0.0 values
14:23:48 mriedem well, it seems pretty obvious to me that we just shouldn't set 0.0 values on the compute node record in _copy_resources if the config is still just 0.0
14:24:31 bauzas mriedem: sure, we could leave the defaults
14:24:44 bauzas because once we pull the object, the facade fixes it for free
14:27:01 mriedem except we're no longer pulling the object in the RT
14:27:09 mriedem which is i think the problem
14:27:58 zigo mriedem: Sure, let me add it.
14:28:24 zigo mriedem: Yes, I package tags.
14:29:06 mriedem zigo: you don't want to add it
14:29:24 bauzas mriedem: sorry, you mean we're getting the CPU, RAM and disk values out of the DB directly ?
14:29:39 bauzas I thought we were still getting by id ?
14:29:42 mriedem zigo: i'm asking because https://review.openstack.org/#/c/520024/ is in master only, not rocky, but it looks like the culprit of the failure - but that wouldn't then explain how you'd be failing in rocky
14:30:17 bauzas me looks at https://github.com/openstack/nova/blob/f534495a427d1683bc536cf003ec02edbf6d8a45/nova/compute/resource_tracker.py#L85
14:31:35 zigo mriedem: I have rc2 packaged, not rc3.
14:31:38 zigo Maybe I should update?
14:32:08 mriedem yeah probably
14:32:13 mriedem or just the GA
14:32:16 mriedem which was released today?
14:32:36 mriedem https://github.com/openstack/nova/tree/18.0.0
14:32:59 mriedem yeah 20 minutes ago http://git.openstack.org/cgit/openstack/nova/tag/?h=18.0.0
14:35:59 zigo Ah, right !
14:36:01 zigo Doing that.
14:36:21 cdent I'm thinking that the positive way of looking at this is that the second _update has been masking a nasty bug for a long time
14:41:48 mriedem oh i'm not surprised that there would be a big pile of tight coupling tape holding this all together
14:42:05 mriedem and why i didn't want to merge that change before the GA
14:49:43 bauzas mriedem: again, the more I read, the more I think we possibly had the original problem once we had https://github.com/openstack/nova/commit/7b95b4d60726b6c8d0e0fe939c408a91ada79e0c
14:49:53 bauzas and .update() was just hiding it
14:50:12 bauzas mriedem: so, do you want me to modify the above and only set the values if not 0.0 ?
14:50:19 bauzas or are you working on this ?
14:52:34 bauzas disclaimer: looking at a long list of openstack-dev threads
15:00:27 mriedem Kevin_Zheng: yikun: you might be interested in https://review.openstack.org/#/c/591976/
15:00:47 mriedem bauzas: i'm working it
15:00:59 bauzas okay
15:01:21 Kevin_Zheng Got it
15:02:31 zigo Nova 18.0.0 built, doing a recheck...
15:03:01 openstackgerrit Merged openstack/nova master: Fix soft deleting vm fails after "nova resize" vm https://review.openstack.org/546920
15:04:36 melwitt .
15:16:00 melwitt stephenfin: on https://review.openstack.org/595592, if the bug is new for rocky, how did moshele run into it on OSP13 (queens)?
15:16:24 stephenfin melwitt: If he's using OSP, then it's because we backported it downstream
15:16:38 stephenfin Even if not, I'd imagine it's a feature backport
15:18:17 melwitt stephenfin: ohh, ok. I didn't think of that, backport of a feature
15:30:40 mriedem ?
15:30:40 mriedem efried: does any kind of nova/cyborg integration actually exist to do anything with servers in rocky/
15:31:02 mriedem b/c https://docs.openstack.org/releasenotes/cyborg/rocky.html says it does
15:31:36 mriedem 1) rocky release notes talk about queens specs
15:31:47 mriedem 2) it sounds like "we completed specs" rather than "we have functioning code"
15:32:51 Kevin_Zheng mriedem: you made me laugh
15:33:43 mriedem i just don't want people showing up in -nova saying "hey why can't i attach fpgas to my vm?"
15:38:28 efried mriedem: No, cyborg has nothing in nova atm
15:38:46 efried oh, yeah, that's poorly worded.
15:41:16 Kevin_Zheng mriedem: we were talking today, about the batch when listing patch
15:42:24 Kevin_Zheng The batch size could vary depending on sort key and dir
15:42:44 Kevin_Zheng Like for sort with uuid
15:43:01 Kevin_Zheng It could be evenly distributed
15:43:24 dansmith Kevin_Zheng: you mean the *optimal* batch size?
15:43:40 Kevin_Zheng dansmith: yeah
15:44:40 dansmith Kevin_Zheng: obviously if you're sorting by uuid it should be fairly evenly distributes and sorting by other things could be massively less well-distributed, but I'm not sure how we could (efficiently) optimize that at runtime
15:44:45 dansmith Kevin_Zheng: do you have ideas?
15:45:00 Kevin_Zheng I was thinking a tool that analyzes dB data
15:45:16 Kevin_Zheng And feed to nova periodically
15:45:30 Kevin_Zheng But that seems to much :)
15:45:36 dansmith yeah :)
15:46:08 dansmith it likely varies by tenant, sort_key, cloud layout, scheduler weights, etc
15:46:17 Kevin_Zheng Just came up when we introduced the new approach to our product team
15:46:18 dansmith it'd be hard to pin that down except for a single-tenant cloud I think
15:46:55 sean-k-mooney mriedem: today i belive you can use cyborg to program a pci device and then you can use nova to pass it through via a pci passthrough flavor alisa but there is no way to force landing on the host with the device you just programed
15:46:57 Kevin_Zheng I’d say it is a powerful tool:)
15:47:33 dansmith Kevin_Zheng: if the goal is to get larger batches from cells likely to have many results, we could do things like scale up the batch size each time you hit a cell again
15:48:03 dansmith Kevin_Zheng: so that if your query is likely to get most results from one cell, we get $batch_size, then $batch_size*2, then $batch_size*4, etc
15:48:25 dansmith but I think I'd want to see a benchmark showing that as worthwhile before I approved it,
15:48:34 Kevin_Zheng Hmm
15:48:51 Kevin_Zheng That could be a good way
15:48:51 dansmith because I expect that since the db query time is so small compared to the processing time, I'm not sure it matters that much (even your hyper-optimized batch sizing tool :)
15:49:26 Kevin_Zheng Yeah, they are just guessing as always
15:49:49 dansmith Kevin_Zheng: yeah :D
15:50:27 dansmith Kevin_Zheng: it's common trap: One big optimization on batch size gives 60% improvement, so assume there are more 60% improvements to be gained through hyper-optimization :)
15:50:34 openstackgerrit Merged openstack/nova-specs master: VMware: add support for live migration https://review.openstack.org/598163
15:59:27 mriedem leave some optimizations for the enterprise fellas
16:01:51 mriedem gibi: you were +2 on this before i robustified the test per mel's prodding https://review.openstack.org/#/c/588943/
16:03:51 Kevin_Zheng maybe left some place for them to be able to do that, like a call to my powerful tool backend :P
16:04:53 mriedem is the toronto lab already working on that?
16:05:15 mriedem research people gotta get grant money somehow
16:05:37 sean-k-mooney mriedem: i will likely be fixing a few things in cyborg in the near future. do you want me to fix the releases note regarding nova inetgration
16:05:43 mriedem need i remind everybody https://www.openstack.org/videos/vancouver-2018/revisiting-scalability-and-applicability-of-openstack-placement-1
16:05:58 mriedem sean-k-mooney: i guess?
16:06:05 mriedem revising release notes is sometimes a tricky business
16:06:47 sean-k-mooney well we update specs retroactivly i done really see release notes as any different

Earlier   Later