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#openstack-nova - 2018-01-22
15:24:18 mgoddard_ cdent, efried: I think a simple answer here is that the resource tracker will always have called set_inventory_for_provider prior to calling set_traits_for_provider, and this ensures that the RPs are present
15:25:21 efried mgoddard_ cdent Ohhh, are we worried about having populated the cache with the relevant provider at this point? I didn't pick up on that at all.
15:25:47 cdent efried: yes, my query has been, all along: is the provider tree active for this code path?
15:26:51 efried cdent That's definitely a legitimate concern, because as documented on set_traits_for_provider (https://github.com/openstack/nova/blob/master/nova/scheduler/client/report.py#L1042) we don't attempt to create the provider. But furthermore, we don't do _ensure_provider either, so there had better have been something prior that populated the cache for that guy.
15:27:37 efried cdent I'm sure I'm just being obtuse, but I didn't understand that from your comments at all :(
15:27:40 mgoddard_ efried: yes, it's set_inventory_for_provider
15:28:58 efried mgoddard_ That's good; and I think it's worth adding a code comment to that effect to affirm that it's been considered. Good call cdent
15:29:27 cdent mgoddard_: how/where does set_inventory_for_provider get involved in the management of the ProviderTree?
15:29:53 efried cdent It calls _ensure_resource_provider first thing.
15:29:57 openstackgerrit Matt Riedemann proposed openstack/nova master: Add the nova-multiattach job https://review.openstack.org/532689
15:30:06 efried cdent Which creates the provider if it doesn't exist, but in any case populates/refreshes the cache
15:31:02 cdent okay, that's the missing piece of the pie, thank you.
15:31:16 mgoddard_ efried: good call, I'll add a comment
15:31:31 efried cdent The other code path, update_compute_node, does the same (_ensure_resource_provider)
15:31:43 cdent I just wanted to be sure, because of what people had said earlier about the potential for confusion
15:32:27 cdent those comments about potential for confusion had made it seem like there was a chance that the provider tree could either be wrong or even not exist
15:32:37 cdent but since it is established by _ensure_* is cool
15:32:51 efried cdent I doubt it's perfect
15:33:30 cdent and how does that make you feel?
15:34:36 efried cdent Dirty. So dirty.
15:34:52 cdent woot
15:35:03 efried cdent For one thing, as noted above, I've convinced myself that concurrency isn't an issue YET.
15:35:33 efried cdent And we're also working on the theory of merge big stuff early so we can shake out the bugs.
15:35:50 efried cdent Not that I think it's a great policy to count on shaking out bugs later rather than avoiding them by careful inspection beforehand...
15:36:13 efried cdent But we also can't get into analysis paralysis. Gotta walk the line.
15:36:22 cdent i like merge big stuff early
15:36:33 cdent as long as we actually exercise
15:36:54 edleafe "early" != "days before feature freeze"
15:37:04 johnthetubaguy mriedem: gibi: apologies, lots of things been getting in my way, but I am +2 on the multi-attach now, went back though the merged chain, I don't feel qualified for +W for some reason, but gibi you might be happy with that?
15:37:16 efried Well, unless feature freeze is deliberately early in the cycle, to allow time to exercise.
15:38:49 mriedem johnthetubaguy: thanks; just cleaning up the patch that adds the CI job so it's run in the check/gate queue
15:39:11 johnthetubaguy mriedem: ah, cool, I did see the -1 on there
15:39:23 mriedem i think zuul got lost in the long chain of deps
15:39:24 mriedem rechecking it
15:39:34 johnthetubaguy cool
15:40:30 mriedem johnthetubaguy: sdague: we'll need this bug fix to get the multiattach job in - relies on not using pike UCA https://review.openstack.org/#/c/532214/
15:40:42 mriedem which means you can't snapshot a paused instance with older libvirt
15:43:39 gibi johnthetubaguy: thanks for the review
15:45:56 gibi mriedem: is it OK for you that I +W the multiattach api patch as john is +2 on it or I should wait for new job to run?
15:46:03 efried rgerganov If you're willing to have https://review.openstack.org/#/c/536348/ rebased onto https://review.openstack.org/#/c/535517/ instead of https://review.openstack.org/#/c/531260/ I'll keep it up to date as I work on those WIPs.
15:46:17 mriedem gibi: should be fine to +W - the CI results have already passed for awhile now
15:46:19 efried rgerganov At the moment you're off on a side branch
15:46:21 mriedem i'm just changing the job config
15:46:32 gibi mriedem: OK, thanks
15:47:41 efried gibi Thanks for the reviews! Knocking 'em out today
15:50:55 mriedem edleafe: looks like https://review.openstack.org/#/c/526436/ needs a rebase?
15:51:32 jaypipes cdent: I see you liked my country music song joke.
15:51:42 cdent quite
15:52:02 jaypipes there's been a plethora of jokes and movie references in reviews on efried's latest patch series.
15:52:11 jaypipes I've been having quite a bit of fun.
15:52:16 edleafe mriedem: working on it
15:52:39 edleafe multiattach stepped on RPC versions
15:53:31 mriedem oh yeah
15:53:34 mriedem it was a race
15:53:47 amorin hello everybody
15:54:36 jaypipes amorin: mornin.
15:54:59 amorin I'd like to know if there is a reason of this if iso9660 line:
15:55:02 amorin https://github.com/openstack/nova/blob/stable/newton/nova/virt/libvirt/driver.py#L6602
15:55:12 amorin I mean, other possibility is vfat afaik
15:55:34 amorin what if nova is transfering the config drive from remote if it is vfat?
15:56:31 amorin jaypipes: evenin :p
15:56:39 amorin (almost 5 pm here)
15:56:45 tovin07 mriedem, hi
15:57:59 jaypipes amorin: well, evening then :)
15:58:13 amorin :)
15:59:44 efried UGT
16:00:11 jaypipes amorin: as for your question... no idea. perhaps mdbooth or lyarwood might know the answer on that one.
16:00:42 amorin jaypipes mdbooth thanks
16:02:12 mdbooth amorin: What's the question?
16:02:46 mdbooth amorin: Ah, you're wondering why the handling difference between iso9660 and vfat?
16:02:49 amorin what if we copy the config-drive no matter its kind (vfat or iso)
16:02:55 amorin yup
16:03:04 efried cdent "For future reference, in the future this loop could be replaced with a single request to POST /allocations, clearing the allocations for all the consumers." <== This must have been a difficult comment to write. The war between "use lots of little API calls" and "use stuff I wrote!" :P
16:03:13 amorin I understand that libvirt is able to copy it if its vfat
16:03:28 amorin but it seems that if nova copy it first,
16:03:30 mdbooth It was (is? but I doubt it) a bug in libvirt/qemu in the handling of iso9660 disks
16:03:34 amorin then libvirt will do nothing
16:03:46 efried cdent Only joshing you of course. The POST is a great idea there.
16:03:50 mdbooth Did you look at the referenced lp bug?
16:03:56 amorin mdbooth: yes
16:04:12 amorin seems that libvirt is still failing with iso
16:04:39 amorin I was just wondering if copying vfat with nova is a bad idea or not
16:05:26 sean-k-mooney amorin: mdbooth i would guesss the bug in libvirt is related to iso beeing treated as cdroms and vfat ect disk being considered hdds or somthin in that vain?
16:06:12 sean-k-mooney amorin: well one way to check would be remove that line and look at the livemigration gate jobs. it might result in both nova and neutron coping the config drive
16:06:18 openstackgerrit Mark Goddard proposed openstack/nova master: Add get_traits() method to ComputeDriver https://review.openstack.org/532290
16:06:18 openstackgerrit Mark Goddard proposed openstack/nova master: Send traits to ironic on server boot https://review.openstack.org/508116
16:06:19 openstackgerrit Mark Goddard proposed openstack/nova master: Implement get_traits() for the ironic virt driver https://review.openstack.org/532288
16:06:20 amorin problem is, imagine you already spawn instances with iso kind, nova needs to copy it before (because of libvirt bug), but in the meantime, you updated the nova config, so CONF.config_drive = vfat
16:06:32 amorin then you never enter this if, and live-migration fail
16:07:11 mdbooth sean-k-mooney: Pretty sure it's something like that. Long time since I had this cached.
16:07:55 mdbooth amorin: So, the other thing that happened since then is that we explicitly specify which disks to migrate using migrateToURI3
16:07:56 amorin sean-k-mooney: I did try to remove it in my lab, seems to work, I'll try to submit and patch and see the results in gate jobs
16:08:46 amorin mdbooth: ok, got it, migrateToURI3 is then able to migrate the vfat config-drive
16:10:10 amorin mdbooth: but are we sure that migrateToURI3 is able to handle the iso kind?
16:10:12 amorin i'll check
16:10:13 mdbooth IIRC it's because cd-rom drives are read-only, and qemu won't let us write to a read-only disk, even during live migration
16:10:43 mdbooth amorin: The pertinent point about migrateToURI3 is that we specify a list of disks to block migrate explicitly
16:10:46 zzzeek jaypipes: my connection monitoring thing currently lets you put ?plugin=connmon on the SQLAlchemy URL. But Nova Cells shoves DB urls into the database the first time it runs and then they never change :(. So need to add a config flag to oslo.db. But then Nova hardcodes all the oslo flags :)
16:10:50 mdbooth Whereas before it was all disks
16:11:03 sean-k-mooney amorin: is there a reason we migate configdirve instead of recreating on remote side our of interest. technically with vfat it can be readwrite but they are intended to be readonly

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